- The Mechanism of the Palladium-catalysed Reaction of Allylic Acetates with Carbonyl Compounds via Electrochemical Reduction
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The mechanism of Pd-catalysed reaction of allylic acetates with carbonyl compounds in the presence of zinc chloride via electroreduction is reported.
- Zhang, Pingping,Zhang, Wuchang,Zhang, Tingfang,Wang, Zhiqin,Zhou, Wenjuan
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- New computational and experimental evidence for the mechanism of the Sakurai reaction
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Reaction of aldehydes with allyltrimethylsilane promoted by BF3 (Sakurai reaction) affords fluorotrimethylsilane and a borylated homoallylic alcohol in a noncatalytic fashion. These reaction products have been identified through 13C
- Bottoni, Andrea,Costa, Anna Luisa,Di Tommaso, Donata,Rossi, Ivan,Tagliavini, Emilio
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- Synthesis of 4-aminotetrahydropyran scaffolds for drug discovery
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Functionalised tetrahydropyran scaffolds were prepared using a tethered enol-ether Prins cyclisation and elaborated to show their potential use in library synthesis. The key 4-hydroxytetrahydropyran scaffold could be readily manipulated to the 4-azidotetr
- Nortcliffe, Andrew,Milne, Gavin D.S.,Hamza, Daniel,Moody, Christopher J.
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- Preparation of active zinc by reduction of zinc chloride with sodium in liquid ammonia and its use in the Barbier reaction
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Active zinc powder produced by reduction of anhydrous zinc chloride with solution of sodium in liquid ammonia exhibits high reactivity in the Barbier type reaction both in THF and liquid ammonia solution.
- Makosza, Mieczysaw,Grela, Karol
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- Synthesis of a new C2-symmetric chirat diol: Application to asymmetric allylboration.
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New C2-symmetric chiral diol 1b was prepared from diol 3a, by a thionyl chloride mediated double elimination, hydrogenation and deprotection sequence. A comparative study of the asymmetric allylboration of benzaldehyde with the allylboronates 1
- Mears, Richard J.,De Silva, Harshani,Whiting, Andrew
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- Reaction Pathway and Transition State of the Zn-Promoted Barbier-Type Reactions of Benzaldehyde and Benzophenone with Allylic Iodides
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The carbonyl-14C kinetic isotope effects and the substituent effects on the reactivity of the Zn-promoted Barbier-type reaction of allyl iodide (3-iodo-1-propene) with benzaldehyde and benzophenone were determined in THF at 25 deg C.The observed normal ca
- Yamataka, Hiroshi,Nishikawa, Kazuyoshi,Hanafusa, Terukiyo
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- Simultaneous coordination and double activation phenomena of carbonyl and epoxy oxygen by bis-titanium reagent as a bidentate lewis acid catalyst
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The new bidentate Ti catalyst, (anthraquinone-1,8- dioxy)bis(triisopropoxy-titanium) (1) can be successfully designed and utilized for the simultaneous coordination to carbonyl substrates. The high double-activation ability of the bidentate Ti catalyst 1 toward carbonyls is emphasized using several synthetic examples in comparison with the corresponding monodentate Ti catalyst. The intermediary coordination complex formation of bidentate 1 with DMF or epoxycyclohexane as a carbonyl or epoxy substrate is characterized by 13C NMR spectroscopy.
- Asao, Naoki,Kii, Satoshi,Hanawa, Hideo,Maruoka, Keiji
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- Chemoselective RuO4 oxidation of phenyl or p-methoxyphenyl groups to carboxylic acid functions in the presence of a tetrahydropyran ring
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We describe the first example of a chemoselective oxidation of phenyl and p-methoxyphenyl groups to carboxylic acid functions in the presence of a tetrahydropyran ring, using 0.02 mol% of RuCl3 and a co-oxidant. The use of NaIO4 as c
- Miranda,Vasconcellos
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- Isostructural mesoporous ionic crystals as a tunable platform for acid catalysis
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Eleven isostructural mesoporous ionic crystals (meso-PICs) are synthesized. The initial activities of the Barbier-Grignard reaction, which is a typical C-C bond formation reaction, catalyzed by the meso-PICs are dependent on the acid dissociation constant
- Kikukawa, Yuji,Kitao, Takashi,Ogiwara, Naoki,Shimoyama, Yuto,Uchida, Sayaka,Weng, Zhewei
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- Structure-activity relationship of formamides as organocatalysts: The significance of formamide structure and conformation
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The impact of the structure and conformation of formamides as organocatalysts was investigated and reported herein as a structure-activity relationship. Selected formamides and some amides were evaluated for their ability to activate allyltrichlorosilane
- Nguyen, Dieu,Akhani, Ravish K.,Sheppard, Cody I.,Wiskur, Sheryl L.
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- Visible Light-Promoted Recyclable Carbon Nitride-Catalyzed Dioxygenation of β,γ-Unsaturated Oximes
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A visible-light-induced dioxygenation of β,γ-unsaturated oximes for the synthesis of diverse useful isoxazolines bearing a hydroxyl moiety was developed by employing graphitic carbon nitride (g-C3N4) as a heterogeneous photocatalyst under an air atmosphere. Noted that, the eminent advantages of this metal-free protocol include step economy, easy operation, a recyclable photocatalyst, external reductant-/oxidant-free and mild reaction conditions. Additionally, mechanistic studies indicated hydroxyl radical was generated under the photocatalysis of g-C3N4.
- Fu, Xiao-Yang,Si, Ya-Feng,Qiao, Li-Peng,Zhao, Yu-Fen,Chen, Xiao-Lan,Yu, Bing
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supporting information
p. 574 - 580
(2021/11/13)
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- Copper-Catalyzed Enantioconvergent Cross-Coupling of Racemic Alkyl Bromides with Azole C(sp2)?H Bonds
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The development of enantioconvergent cross-coupling of racemic alkyl halides directly with heteroarene C(sp2)?H bonds has been impeded by the use of a base at elevated temperature that leads to racemization. We herein report a copper(I)/cinchona-alkaloid-derived N,N,P-ligand catalytic system that enables oxidative addition with racemic alkyl bromides under mild conditions. Thus, coupling with azole C(sp2)?H bonds has been achieved in high enantioselectivity, affording a number of potentially useful α-chiral alkylated azoles, such as 1,3,4-oxadiazoles, oxazoles, and benzo[d]oxazoles as well as 1,3,4-triazoles, for drug discovery. Mechanistic experiments indicated facile deprotonation of an azole C(sp2)?H bond and the involvement of alkyl radical species under the reaction conditions.
- Chang, Xiao-Yong,Chen, Ji-Jun,Gu, Qiang-Shuai,Jiang, Sheng-Peng,Li, Zhong-Liang,Liu, Lin,Liu, Xiao-Dong,Liu, Xin-Yuan,Su, Xiao-Long,Wang, Fu-Li,Yang, Chang-Jiang,Ye, Liu
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supporting information
p. 380 - 384
(2020/10/30)
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- Remote Arylative Substitution of Alkenes Possessing an Acetoxy Group via β-Acetoxy Elimination
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Palladium-catalyzed remote arylative substitution was achieved for the reaction of arylboronic acids with alkenes possessing a distant acetoxy group to provide arylation products having an alkene moiety at the remote position. The use of β-acetoxy elimination as a key step in the catalytic cycle allowed for regioselective formation of unstabilized alkenes after chain walking. This reaction was applicable to various arylboronic acids as well as alkene substrates.
- Kakiuchi, Fumitoshi,Kochi, Takuya,Kumagai, Takaaki,Muto, Kazuma
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supporting information
p. 24500 - 24504
(2021/10/19)
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- Structure-Activity Studies of Truncated Latrunculin Analogues with Antimalarial Activity
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Malarial parasites employ actin dynamics for motility, and any disruption to these dynamics renders the parasites unable to effectively establish infection. Therefore, actin presents a potential target for malarial drug discovery, and naturally occurring actin inhibitors such as latrunculins are a promising starting point. However, the limited availability of the natural product and the laborious route for synthesis of latrunculins have hindered their potential development as drug candidates. In this regard, we recently described novel truncated latrunculins, with superior actin binding potency and selectivity towards P. falciparum actin than the canonical latrunculin B. In this paper, we further explore the truncated latrunculin core to summarize the SAR for inhibition of malaria motility. This study helps further understand the binding pattern of these analogues in order to develop them as drug candidates for malaria.
- Varghese, Swapna,Rahmani, Rapha?l,Drew, Damien R.,Beeson, James G.,Baum, Jake,Smith, Brian J.,Baell, Jonathan B.
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p. 679 - 693
(2020/11/30)
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- Asymmetric Allylation Catalyzed by Chiral Phosphoric Acids: Stereoselective Synthesis of Tertiary Alcohols and a Reagent-Based Switch in Stereopreference
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The substrate scope of the asymmetric allylation with zinc organyls catalyzed by 3,3-bis(2,4,6-triisopropylphenyl)-1,1-binaphthyl-2,2-diyl hydrogenphosphate (TRIP) has been extended to non-cyclic ester organozinc reagents and ketones. Tertiary chiral alcohols are obtained with ee's up to 94% and two stereogenic centers can be created. Compared to the previous lactone reagent the stereopreference switches almost completely, proving the fact that the nature of the organometallic compound is of immense importance for the asymmetry of the product. (Figure presented.).
- Lazzarotto, Mattia,Hartmann, Peter,Pletz, Jakob,Belaj, Ferdinand,Kroutil, Wolfgang,Payer, Stefan E.,Fuchs, Michael
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supporting information
p. 3138 - 3143
(2021/04/28)
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- Photoredox Allylation Reactions Mediated by Bismuth in Aqueous Conditions
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Organometallic allylic reagents are widely used in the construction of C?C bonds by Barbier-type reactions. In this communication, we have described a photoredox Barbier allylation of aldehydes mediated by bismuth, in absence of other metals as co-reductants. Mild reaction conditions, tolerance of oxygen, and use of aqueous solvent make this photoredox methodology attractive for green and sustainable synthesis of homoallylic alcohols.
- Potenti, Simone,Gualandi, Andrea,Puggioli, Alessio,Fermi, Andrea,Bergamini, Giacomo,Cozzi, Pier Giorgio
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supporting information
p. 1624 - 1627
(2021/02/05)
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- Silylcyclopropanes by Selective [1,4]-Wittig Rearrangement of 4-Silyl-5,6-dihydropyrans
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4-Silyl-5,6-dihydropyrans undergo remarkably selective [1,4]-Wittig rearrangements to give silylcyclopropanes in good yields. The selectivity is independent of the silyl group, but it is influenced by the electronic character of the migrating center. Elec
- Mori-Quiroz, Luis M.,Maloba, Emmanuel W.,Maleczka, Robert E.
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supporting information
p. 5724 - 5728
(2021/07/31)
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- Nickel-Catalyzed Reductive Allylation of Aldehydes with Allyl Acetates
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Carbonyl allylation reactions constitute an important step in the formation of carbon-carbon reactions, and involve various related reactions that chiefly use allylmetal reagents. This report presents a nickel-catalyzed carbonyl allylation reaction using allyl acetate, which produces homoallyl alcohols in moderate to good yields, as an efficient methodology under reductive coupling conditions.
- Suzuki, Hiroyuki,Yamaguchi,Itoh, Akichika
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p. 1489 - 1494
(2020/12/13)
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- Catalytic Photoredox Allylation of Aldehydes Promoted by a Cobalt Complex
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The preparation of homoallylic alcohols by addition of organometallic allyl compounds to carbonyls is an important strategy in organic chemistry. Allylating organometallic cobalt species can be generated employing stoichiometric quantities of Zn acting as reductant. To avoid the employment of stoichiometric amount of Zn, we have developed an allylation reaction of aromatic and aliphatic aldehydes promoted by photoredox catalysis in the presence of a cobalt complex, and we present herein a full account of our research. In the presence of the abundant CoBr2 (10 mol %), 4,4′-di-tert-butyl-2,2′-dipyridyl (dtbbpy, 10 mol %), allyl acetate (3 equiv.), [Ir(dtbbpy)(ppy)2]PF6 (ppy=2-phenylpyridine, 2 mol %), and N,N-diisopropylethylamine (4 equiv.), an allylation of aldehydes is taking place, in moderate to good yields. Substrates scope, limitations, and photophysical investigations of this new process are reported. (Figure presented.).
- Gualandi, Andrea,Rodeghiero, Giacomo,Perciaccante, Rossana,Jansen, Thomas Paul,Moreno-Cabrerizo, Cristina,Foucher, Charles,Marchini, Marianna,Ceroni, Paola,Cozzi, Pier Giorgio
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supporting information
p. 1105 - 1111
(2021/01/04)
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- Photocatalytic Umpolung Synthesis of Nucleophilic π-Allylcobalt Complexes for Allylation of Aldehydes
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The concept of "umpolung"reactivity of π-allylmetal complexes has been developed as a powerful method for the allylation of aldehydes. This paper describes the photocatalytic umpolung strategy for the synthesis of nucleophilic allylcobalt complexes through a single-electron-transfer (SET) process. This strategy enables the metallaphotoredox allylation of carbonyls with allyl acetate using organic N,N-diisopropylethylamine as the terminal reductant bypassing the use of a stoichiometric amount of metals. Ultraviolet-visible spectroscopy was used to monitor the redox changes of cobalt in the reaction.
- Shi, Caizhe,Li, Fusheng,Chen, Yuqing,Lin, Shuangjie,Hao, Erjun,Guo, Zhuowen,Wosqa, Urwa Tul,Zhang, Dandan,Shi, Lei
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p. 2992 - 2998
(2021/03/09)
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- Indium-mediated allylation of carbonyl compounds in deep eutectic solvents
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This study describes, for the first time, the in situ generation of indium organometallic reagents in environmentally friendly deep eutectic solvents (DESs). The allylation process of different carbonyl compounds is achieved mediated by indium metal and u
- González-Gallardo, Nerea,Saavedra, Beatriz,Guillena, Gabriela,Ramón, Diego J.
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- Rhodium-Catalyzed Remote Isomerization of Alkenyl Alcohols to Ketones
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We develop herein an efficient rhodium-catalyzed remote isomerization of aromatic and aliphatic alkenyl alcohols into ketones. This catalytic process, with a commercially available catalyst and ligand ([RhCl(cod)]2 and Xantphos), features high efficiency, low catalyst loading, good functional group tolerance, a broad substrate scope, and no (sub)stoichiometric additive. Preliminary mechanistic studies suggest that this transformation involves an iterative dissociative β-hydride elimination-migration insertion process.
- Dong, Wenke,Yang, Hongxuan,Yang, Wen,Zhao, Wanxiang
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supporting information
(2020/02/28)
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- Highly Enantioselective Construction of Dihydrooxazines via Pd-Catalyzed Asymmetric Carboetherification
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A straightforward synthesis of highly enantioenriched 5,6-dihydro-4H-1,2-oxazines is realized by Pd-catalyzed asymmetric carboetherification of γ,δ-alkenyl oximes with (hetero)aryl and alkenyl halides in the presence of a commercially available bisphosphine ligand. The enantioenriched products can be facilely converted to functionalized alcohols with high fidelity of chiral transfer.
- Li, Na,Sun, Baozhen,Liu, Shuang,Zhao, Jinbo,Zhang, Qian
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supporting information
p. 190 - 193
(2020/01/02)
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- Enantioselective Synthesis of Isoxazolines Enabled by Palladium-Catalyzed Carboetherification of Alkenyl Oximes
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Reported here is a highly efficient Pd/Xiang-Phos catalyzed enantioselective carboetherification of alkenyl oximes with either aryl or alkenyl halides, delivering various chiral 3,5-disubstituted and 3,5,5-trisubstituted isoxazolines in good yields with u
- Chen, Mingjie,Li, Wenbo,Wang, Lei,Wang, Yuzhuo,Zhang, Junliang,Zhang, Kenan
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supporting information
p. 4421 - 4427
(2020/02/11)
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- Regioselective Synthesis of Arylsulfonyl Benzophenones via Aerobic Oxidative [3+3] Benzannulation Reactions
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Regioselective synthesis of 3-arylsulfonyl benzophenone derivatives via base mediated, aerial-oxidative [3+3] benzannulation of α,β-unsaturated aldehydes and 4-sulfonyl butenones is reported. A variety of readily available acyclic building blocks are tran
- Yadav, Deepak,Joshi, Prabhakar R.,Sharma, Sunil K.,Menon, Rajeev S.
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p. 6370 - 6374
(2020/10/19)
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- Cp2TiCl2-Catalyzed Photoredox Allylation of Aldehydes with Visible Light
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A Barbier-type Cp2TiCl2-mediated (10 mol %) photoredox allylation of aldehydes under irradiation with visible light (blue light-emitting diodes (LEDs), 450 nm) and in the presence of an organic dye (3DPAFIPN, 5 mol %) with allylbromides is described.
- Bergamini, Giacomo,Calogero, Francesco,Cozzi, Pier Giorgio,Fermi, Andrea,Gualandi, Andrea,Guazzi, Simone,Mazzarini, Martino
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p. 3857 - 3863
(2020/03/26)
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- Copper-Impregnated Magnesium-Lanthanum Mixed Oxide: A Reusable Heterogeneous Catalyst for Allylation of Aldehydes and Ketones
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Copper-impregnated magnesium-lanthanum mixed oxide [Cu(II)/Mg?La] was used as catalyst in synthesis of homoallylic alcohols from aldehydes and ketones using allyltributylstannane as the allylating source. The present protocol provides a great application
- Laha, Soumi,Likhar, Pravin R.,Pogula, Jaya,Sreedhar, B.
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supporting information
(2020/02/11)
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- NHC Core Phosphonium Ylide-based Palladium(II) Pincer Complexes: The Second Ylide Extremity Makes the Difference
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The coordinating properties of N-heterocyclic carbene (NHC) (A), phenolate (B), and phosphonium ylide (C) moieties were investigated systematically through the preparation of a family of NHC, phosphonium ylide-based pincer ligands, where the third donor e
- Taakili, Rachid,Barthes, Cécile,Go?ffon, Amel,Lepetit, Christine,Duhayon, Carine,Valyaev, Dmitry A.,Canac, Yves
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p. 7082 - 7096
(2020/05/13)
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- Recyclable Polyisobutylene-Bound HMPA as an Organocatalyst in Recyclable Poly(α-olefin) Solvents
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This work describes the synthesis of a PIB-bound hexamethylphosphoramide (HMPA) analog and its applications as a recyclable catalyst in allylation of aldehydes and reduction of enones in a recyclable poly(α-olefin) (PAO) polymeric solvent. Kinetic studies of the allylation reaction show that this PIB-bound HMPA analog is as active as HMPA in dichloromethane and PAO and that this PIB-bound catalyst is comparably reactive in heptane and in a PAO solvent. The PIB-bound HMPA catalyst has high phase selective solubility in PAO versus a polar solvent. By using this catalyst in a nonvolatile separable PAO solvent, this catalyst recyclability can be coupled to solvent recyclability, something that is less feasible in a conventional heptane solvent. The result is good recycling of catalyst and solvent through at least 5 cycles using simple gravity-based liquid/liquid extractions. This is in contrast to HMPA or conventional solvents which are less recyclable.
- Fu, Ying-Hua,Bergbreiter, David E.
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p. 6050 - 6058
(2020/10/19)
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- Application of metallocene rare earth metal complex in catalyzing aldehyde and allyl boric acid reaction
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The invention discloses a preparation method of allyl alcohol. The preparation method comprises the following steps of: in an anhydrous anaerobic environment and an inert gas atmosphere, adding a tricyclopentadienyl rare earth metal complex into a reaction flask; adding n-heptaldehyde, performing uniform mixing; and adding allylboronic acid, and carrying out a reaction to prepare allyl alcohol. The method has the advantages of mild reaction conditions, improvement of the catalytic activity, reduction of the preparation difficulty of a catalyst, and reduction of post-treatment cost.
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Paragraph 0016; 0023-0028
(2020/10/19)
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- Photochemical oxidation of benzylic primary and secondary alcohols utilizing air as the oxidant
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A mild and green photochemical protocol for the oxidation of alcohols to aldehydes and ketones was developed. Utilizing thioxanthenone as the photocatalyst, molecular oxygen from air as the oxidant and cheap household lamps or sunlight as the light source, a variety of primary and secondary alcohols were converted into the corresponding aldehydes or ketones in low to excellent yields. The reaction mechanism was extensively studied.
- Nikitas, Nikolaos F.,Tzaras, Dimitrios Ioannis,Triandafillidi, Ierasia,Kokotos, Christoforos G.
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p. 471 - 477
(2020/02/13)
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- Development of a Practical, Biocatalytic Synthesis of tert-Butyl (R)-3-Hydroxyl-5-hexenoate: A Key Intermediate to the Statin Side Chain
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The HMG-CoA reductase inhibitors, statins, are one of the most effective and bestselling cholesterol-lowering drugs. The use of statins has greatly extended people's lives and improved the quality of their life. Development of a more efficient, stereoselective, and sustainable synthesis of statins is continuingly of utmost importance. In the present study, through screening of ketoreductases (KREDs) and reaction optimization, we have successfully performed a highly stereoselective reduction of ketoester 1a catalyzed by KRED-06 at a pilot-plant scale without the addition of exogenous NADP+, generating 3.21 kg of enantiomerically pure tert-butyl (R)-3-hydroxyl-5-hexenoate ((R)-2a) (96.2% yield, >99.9% enantiomeric excess (ee)). This newly developed biocatalytic process alleviates the cryogenic conditions (-40 °C) employed in our first-generation synthesis of (R)-2a using NaBH4 and (l)-tartaric acid. Coupled with our previously established synthesis of bromocarbonate 3a via a one-pot diastereoselective carboxylation/bromocyclization of (R)-2a, we have developed an innovative, practical synthesis route to statin side chain, possessing great potential to be implemented into industrial production of statins.
- Chen, Fener,Hu, Chen,Huang, Zedu,Liu, Minjie,Yue, Xiaoping
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supporting information
p. 1700 - 1706
(2020/10/26)
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- Copper-Catalyzed Aerobic Cyclization of β,γ-Unsaturated Hydrazones with Concomitant CC Bond Cleavage
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A Cu-catalyzed aerobic oxidative cyclization of β,γ-unsaturated hydrazones for the preparation of pyrazole derivatives has been developed. The hydrazonyl radical promoted the cyclization, along with a concomitant CC bond cleavage of β,γ-unsaturated hydrazones. This process has been verified via several control experiments, including a radical-trapping study, an 18O-labeling method, and the identification of the possible byproducts. The advantages of this reaction include operational simplicity, a broad reaction scope, and a mild selective reaction process.
- Fan, Zhenwei,Feng, Jiahao,Hou, Yuchen,Rao, Min,Cheng, Jiajia
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p. 7981 - 7985
(2020/11/02)
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- Photocontrolled Cobalt Catalysis for Selective Hydroboration of α,β-Unsaturated Ketones
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Selectivity between 1,2 and 1,4 addition of a nucleophile to an α,β-unsaturated carbonyl compound has classically been modified by the addition of stoichiometric additives to the substrate or reagent to increase their “hard” or “soft” character. Here, we demonstrate a conceptually distinct approach that instead relies on controlling the coordination sphere of a catalyst with visible light. In this way, we bias the reaction down two divergent pathways, giving contrasting products in the catalytic hydroboration of α,β-unsaturated ketones. This includes direct access to previously elusive cyclic enolborates, via 1,4-selective hydroboration, providing a straightforward and stereoselective route to rare syn-aldol products in one-pot. DFT calculations and mechanistic experiments confirm two different mechanisms are operative, underpinning this unusual photocontrolled selectivity switch.
- Beltran, Frédéric,Bergamaschi, Enrico,Funes-Ardoiz, Ignacio,Teskey, Christopher J.
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supporting information
p. 21176 - 21182
(2020/09/17)
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- Helicity Induction and Its Static Memory of Poly(biphenylylacetylene)s Bearing Pyridine N-Oxide Groups and Their Use as Asymmetric Organocatalysts
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Novel poly(biphenylylacetylene) derivatives carrying different types of pyridine N-oxide units with a bulky or less-bulky substituent at a different position as the functional pendant groups (poly-2a and poly-2b) were synthesized by the rhodium-catalyzed
- Ando, Mitsuka,Ishidate, Ryoma,Ikai, Tomoyuki,Maeda, Katsuhiro,Yashima, Eiji
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p. 2481 - 2490
(2019/11/03)
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- Cationic Cobalt Porphyrin-Catalyzed Allylation of Aldehydes with Allyltrimethylsilanes
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Cationic cobalt porphyrin-catalyzed allylation of aldehydes with allyltrimethylsilanes is developed. The formation of the aldehyde-cobalt porphyrin complex, the key intermediate for the addition of allylsilanes, is confirmed by theoretical studies and syn
- Tomifuji, Rei,Masuda, Shota,Kurahashi, Takuya,Matsubara, Seijiro
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supporting information
p. 3834 - 3837
(2019/05/24)
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- Synthesis of Enantiomerically Pure 5,6-Dihydropyran-2-ones via Chemoenzymatic Sequential DKR-RCM Reaction
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The enantiomerically pure 5,6-dihydropyran-2-ones play a crucial role as the building blocks in the synthesis of various bioactive compounds. A new straightforward protocol toward enantiomerically pure 5,6-dihydropyran-2-ones based on enzymatic dynamic ki
- Koszelewski, Dominik,Borys, Filip,Brodzka, Anna,Ostaszewski, Ryszard
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supporting information
p. 1653 - 1658
(2019/01/24)
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- Method for synthesizing 8th-site substituted-3,4,7,8-tetrahydro-2H-oxocin-2-one octatomic ring
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The invention discloses a method for synthesizing 8th-site substituted-3,4,7,8-tetrahydro-2H-oxocin-2-one octatomic ring. The synthesis method includes the following steps: performing Grignard reaction on an aldehyde or ketone to obtain an allyl alcohol compound; and performing condensation reaction with 2-(tert-butylsulfonyl)acetic acid to obtain an allyl (tert-butylsulfonyl)acetate compound; performing olefin cross-metathesis reaction under the action of a second generation Grubbs catalyst to obtain a methoxycarbonyl (tert-butylsulfonyl)acetate compound; performing intramolecular reaction byusing anhydrous N,N-dimethylformamide as a solvent in the presence of a catalyst palladium acetate and a ligand triphenylphosphine, so as to produce a 3-tert-butylsulfonyl 8th-site substituted-3,4,7,8-tetrahydro-2H-oxocin-2-one octatomic ring lactone compound; and finally removing tert-butylsulfonyl in a reaction solution of sodium amalgam and acetic acid by taking ethanol as a solvent, so as toobtain 8th-site substituted-3,4,7,8-tetrahydro-2H-oxocin-2-one octatomic ring lactone compound. The yield of the method is high, and a solution with a very dilute reaction concentration is not neededin the synthesis of various substituted octatomic ring lactones through intramolecular catalysis by palladium, so the process conditions are simple and universal.
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Paragraph 0018-0023
(2019/10/01)
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- In Situ Generated Gold Nanoparticles on Active Carbon as Reusable Highly Efficient Catalysts for a Csp3 ?Csp3 Stille Coupling
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Gold nanoparticle catalysts are important in many industrial production processes. Nevertheless, for traditional Csp2-Csp2 cross-coupling reactions they have been rarely used and Pd catalysts usually give a superior performance. Herein we report that in situ formed gold metal nanoparticles are highly active catalysts for the cross coupling of allylstannanes and activated alkylbromides to form Csp3-Csp3 bonds. Turnover numbers up to 29 000 could be achieved in the presence of active carbon as solid support, which allowed for convenient catalyst recovery and reuse. The present study is a rare case where a gold metal catalyst is superior to Pd catalysts in a cross-coupling reaction of an organic halide and an organometallic reagent.
- Holz, Julia,Pfeffer, Camilla,Zuo, Hualiang,Beierlein, Dennis,Richter, Gunther,Klemm, Elias,Peters, René
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supporting information
p. 10330 - 10334
(2019/06/27)
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- A chemoenzymatic synthesis of ceramide trafficking inhibitor HPA-12
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A chemoenzymatic synthesis of the title compound has been developed using an efficient and highly enantioselective lipase-catalyzed acylation in a hydrophobic ionic liquid, [bmim][PF6], followed by a diastereoselective asymmetric dihydroxylatio
- Kanojia, Seema V.,Chatterjee, Sucheta,Chattopadhyay, Subrata,Goswami, Dibakar
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supporting information
p. 490 - 496
(2019/03/07)
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- Use of allylzinc halide as a source of halide: Differential addition of nucleophiles to Ts-aziridines and aldehydes under similar reaction conditions
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We have observed that the allylic zinc halide under identical reaction conditions acts in different modes for different electrophiles. For Ts-aziridines the halide part of the allylic halide has been introduced as a nucleophile and for the carbonyl compou
- Chatterjee, Rana,Samanta, Satyajit,Mukherjee, Anindita,Santra, Sougata,Zyryanov, Grigory V.,Majee, Adinath
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supporting information
p. 276 - 283
(2019/01/04)
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- Synthesis of Cage-Shaped Aluminum Aryloxides: Efficient Lewis Acid Catalyst for Stereoselective Glycosylation Driven by Flexible Shift of Four- To Five-Coordination
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Monomeric cage-shaped aluminum aryl oxides 1Al were synthesized using tripodal triphenolic ligands. The Lewis acidity and catalytic activity of the obtained 1Al·py were investigated. The Lewis acidity of 1Al·py originates from the flexible change in the c
- Tanaka, Daiki,Kadonaga, Yuichiro,Manabe, Yoshiyuki,Fukase, Koichi,Sasaya, Shota,Maruyama, Hikaru,Nishimura, Sota,Yanagihara, Mayu,Konishi, Akihito,Yasuda, Makoto
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supporting information
p. 17466 - 17471
(2019/10/14)
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- BICYCLIC COMPOUNDS FOR USE AS RIP1 KINASE INHIBITORS
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The invention provides novel compounds having the general formula (I) or pharmaceutically acceptable salts thereof, wherein RA, RB1, RB2, the A ring and the B ring are as described herein, pharmaceutical compositions inclu
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Page/Page column 43
(2019/05/07)
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- N-[4-OXO-2,3-DIHYDRO-1,5-BENZOXAZEPIN-3-YL]-5,6-DIHYDRO-4H-PYRROLO[1,2-B]PYRAZOL E-2-CARBOXAMIDE DERIVATIVES AND RELATED COMPOUNDS AS RIP1 KINASE INHIBITORS FOR TREATING E.G. IRRITABLE BOWEL SYNDROME (IBS)
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The invention provides compounds having the general formula (I): or pharmaceutically acceptable salts thereof, wherein X, Y, R1, R2, R7a, R7b, X, RB1, RB2, n, p, q, the A ring and the B ring are as described herein, pharmaceutical compositions including the compounds, and the compounds for use as receptor-interacting protein-1 (RIP1) kinase inhibitors in methods of treating e.g. Parkinson's or Alzheimer's disease, irritable bowel disorders (IBD), Crohn's disease, respiratory distress syndrome (ARDS) or chronic obstructive pulmonary disease (COPD). An exemplary compound is e.g. (4S,6S)-4-fluoro-6-phenyl-N-[(3S)-5-methyl-4-oxo-2,3-dihydro-l,5- benzoxazepin-3-yl]-5,6-dihydro-4H-pyrrolo[l,2-b]pyrazole-2- carboxamide (example 11) with a Ki (uM) in a RIP1 assay of 0.0044 uM..
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Page/Page column 37; 41
(2019/11/12)
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- BICYCLIC KETONE COMPOUNDS AND METHODS OF USE THEREOF
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The invention provides novel compounds having the general formula (I): (I) wherein R1, the A ring and the B ring are as described herein, pharmaceutical compositions including the compounds, and methods of using the compounds.
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Page/Page column 53; 54
(2019/02/02)
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- Synthesis of helical π-conjugated polymers bearing pyridine: N -oxide pendants and asymmetric allylation of aldehydes in the helical cavity
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Catalytically active chiral π-conjugated polymers (poly-1(NO)r) bearing pyridine N-oxide pendants were synthesized by ternary copolymerization of a d-glucose-bound diethynyl compound with two types of thieno[3,4-b]thiophene comonomer, one of wh
- Ikai, Tomoyuki,Yoshida, Takumu
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p. 8537 - 8540
(2019/10/02)
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- Allylation of aldehydes by dual photoredox and nickel catalysis
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Here we report the application of dual nickel/photoredox catalysis to the allylation of aliphatic, aromatic and heteroaromatic aldehydes by using commercially available reagents. The process utilizes the combination of a Ni(ii) complex, [Ru(bpy)3]2+ as a photoredox catalyst, and allylacetate under blue LED irradiation, and allows the synthesis of a large variety of homoallylic alcohols.
- Gualandi, Andrea,Rodeghiero, Giacomo,Faraone, Adriana,Patuzzo, Filippo,Marchini, Marianna,Calogero, Francesco,Perciaccante, Rossana,Jansen, Thomas Paul,Ceroni, Paola,Cozzi, Pier Giorgio
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supporting information
p. 6838 - 6841
(2019/06/18)
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- Synthesis of new bipyridine N,N′-dioxides and their application in asymmetric allylation of benzaldehyde and aldol addition to acetophenone
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Abstract: Two methods for the synthesis of new axially chiral bipyridine N,N′-dioxides based on catalytic [2+2+2] cyclotrimerization of diynes with nitriles were developed. The N,N′-dioxides were used as catalysts in enantioselective allylation of benzaldehyde with allyltrichlorosilane and aldol reaction of trichlorosilyl ketene acetal of methyl acetate with acetophenone. Graphical abstract: [Figure not available: see fulltext.].
- Bedná?ová, Eva,Ne?as, David,Císa?ová, Ivana,Du?ek, Michal,Lamaty, Frédéric,Kotora, Martin
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- Highly Focused Library-Based Engineering of Candida antarctica Lipase B with (S)-Selectivity Towards sec-Alcohols
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Candida antarctica lipase B (CALB) is one of the most extensively used biocatalysts in both academia and industry and exhibits remarkable (R)-enantioselectivity for various chiral sec-alcohols. Considering the significance of tailor-made stereoselectivity in organic synthesis, a discovery of enantiocomplementary lipase mutants with high (R)- and (S)-selectivity is valuable and highly desired. Herein, we report a highly efficient directed evolution strategy, using only 4 representative amino acids, namely, alanine (A), leucine (L), lysine (K), tryptophan (W) at each mutated site to create an extremely small library of CALB variants requiring notably less screening. The obtained best mutant with three mutations W104V/A281L/A282K displayed highly reversed (S)-selectivity towards a series of sec-alcohol with E values up to 115 (conv. 50%, ee 94%). Compared with the previously reported (S)-selective CALB variant, W104A, a single mutation provided less selectivity, while the synergistic effects of three mutations in the best variant endow better (S)-selectivity and a broader substrate scope than the W104A variant. Structural analysis and molecular dynamics simulation unveiled the source of reversed enantioselectivity. (Figure presented.).
- Cen, Yixin,Li, Danyang,Xu, Jian,Wu, Qiongsi,Wu, Qi,Lin, Xianfu
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p. 126 - 134
(2018/12/05)
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- Synthesis of Benzylic Alcohols by C-H Oxidation
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Selective methylene C-H oxidation for the synthesis of alcohols with a broad scope and functional group tolerance is challenging due to the high proclivity for further oxidation of alcohols to ketones. Here, we report the selective synthesis of benzylic alcohols employing bis(methanesulfonyl) peroxide as an oxidant. We attempt to provide a rationale for the selectivity for monooxygenation, which is distinct from previous work; a proton-coupled electron transfer mechanism (PCET) may account for the difference in reactivity. We envision that our method will be useful for applications in the discovery of drugs and agrochemicals.
- Tanwar, Lalita,B?rgel, Jonas,Ritter, Tobias
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supporting information
p. 17983 - 17988
(2019/11/14)
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- Catalytic Nucleophilic Allylation Driven by the Water-Gas Shift Reaction
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The ruthenium-catalyzed allylation of aldehydes with allylic pro-nucleophiles has been demonstrated to be an efficient means to form carbon-carbon bonds under mild conditions. The evolution of this reaction from the initial serendipitous discovery to its general synthetic scope is detailed, highlighting the roles of water, CO, and amine in the generation of a more complete catalytic cycle. The use of unsymmetrical allylic pro-nucleophiles was shown to give preferential product formation through the modulation of reaction conditions. Both (E)-cinnamyl acetate and vinyl oxirane were efficiently used to form the anti-branched products (up to >20:1 anti/syn) and E-linear products (up to >20:1 E/Z) in high selectivity with aromatic, α,β-unsaturated, and aliphatic aldehydes, respectively. Attempts to render the reaction enantioselective are highlighted and include enantioenrichment of up to 75:25 for benzaldehyde.
- Denmark, Scott E.,Matesich, Zachery D.,Nguyen, Son T.,Milicevic Sephton, Selena
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supporting information
p. 23 - 48
(2018/02/19)
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- Copper-Catalyzed One-Pot Borylative Aldolisation β-Fluoride Elimination for the Formal Addition of Acrylates to Carbonyl Moieties
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Herein, we report the copper-catalyzed domino borylation/aldolisation of methyl 2-fluoroacrylate with carbonyl compounds followed by an elimination to give Morita–Baylis–Hillman (MBH) analogues. The optimal conditions described were shown to be compatible
- Rasson, Corentin,Stouse, Adrien,Boreux, Arnaud,Cirriez, Virginie,Riant, Olivier
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supporting information
p. 9234 - 9237
(2018/06/04)
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- Multicatalytic Stereoselective Synthesis of Highly Substituted Alkenes by Sequential Isomerization/Cross-Coupling Reactions
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Starting from readily available alkenyl methyl ethers, the stereoselective preparation of highly substituted alkenes by two complementary multicatalytic sequential isomerization/cross-coupling sequences is described. Both elementary steps of these sequences are challenging processes when considered independently. A cationic iridium catalyst was identified for the stereoselective isomerization of allyl methyl ethers and was found to be compatible with a nickel catalyst for the subsequent cross-coupling of the in situ generated methyl vinyl ethers with various Grignard reagents. The method is compatible with sensitive functional groups and a multitude of olefinic substitution patterns to deliver products with high control of the newly generated C=C bond. A highly enantioselective variant of this [Ir/Ni] sequence has been established using a chiral iridium precatalyst. A complementary [Pd/Ni] catalytic sequence has been optimized for alkenyl methyl ethers with a remote C=C bond. The final alkenes were isolated with a lower level of stereocontrol. Upon proper choice of the Grignard reagent, we demonstrated that C(sp2) - C(sp2) and C(sp2) - C(sp3) bonds can be constructed with both systems delivering products that would be difficult to access by conventional methods.
- Romano, Ciro,Mazet, Clément
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supporting information
p. 4743 - 4750
(2018/04/10)
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- Water-Compatible Synthesis of 2-Trifluoromethyl-1,3-Dioxanes
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A water-compatible method for the diastereoselective synthesis of 2-trifluormethyl-1,3-dioxanes is described. The reaction proceeds under mild reaction conditions using simple inorganic bases; it has a very good substrate scope and can be performed with different Michael acceptors. Additionally, the reaction products can be further functionalized, showing an excellent perspective for future applications.
- Becerra-Figueroa, Liliana,Tiniakos, Alexander F.,Prunet, Jo?lle,Gamba-Sánchez, Diego
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supporting information
p. 6929 - 6932
(2018/11/25)
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- Bi-mediated allylation of aldehydes in [bmim][Br]: A mechanistic investigation
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The inexpensive room temperature ionic liquid (RTIL), [bmim][Br] has been found to be a superior medium for the Bi-mediated Barbier-type allylation of aldehydes compared to other conventional solvents. It plays the dual role of a solvent and a metal activ
- Koli, Mrunesh,Chatterjee, Sucheta,Chattopadhyay, Subrata,Goswami, Dibakar
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supporting information
p. 2198 - 2203
(2018/09/04)
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- Photocatalytic Barbier reaction-visible-light induced allylation and benzylation of aldehydes and ketones
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We report a photocatalytic version of the Barbier type reaction using readily available allyl or benzyl bromides and aromatic aldehydes or ketones as starting materials to generate allylic or benzylic alcohols. The reaction proceeds at room temperature under visible light irradiation with the organic dye 3,7-di(4-biphenyl)1-naphthalene-10-phenoxazine as a photocatalyst and DIPEA as sacrificial electron donor. The proposed cross-coupling mechanism of a ketyl- and an allyl or benzyl radical is supported by spectroscopic investigations and cyclic voltammetry measurements.
- Berger, Anna Lucia,Donabauer, Karsten,K?nig, Burkhard
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p. 7230 - 7235
(2018/10/02)
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- Indium-mediated allylation of carbonyl compounds in ionic liquids: Effect of salts in ionic liquids
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The In-mediated allylation of carbonyl compounds can be performed in various types of solvents including ionic liquids. However, we have found that in [bmim][BF4] (where bmim = 1-butyl-3-methylimidazolium), the In-mediated coupling of crotyl bromide with benzaldehyde gives a complex mixture, and some additives, such as halides and amines, are crucial for the successful conversion to the corresponding γ-adduct. Instead, the addition of alcohols or water promotes the formation of the α-adduct. An asymmetric induction with up to 62% enantiomeric excess (ee) was observed employing cinchonidine as an additive in a binary solvent consisting of an ionic liquid and dichloromethane.
- Hirashita, Tsunehisa,Takahashi, Fusako,Noda, Takayuki,Takagi, Yuji,Araki, Shuki
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- Syntheses of 4-Acetoxy-or acetylthio-2-substituted tetrahydrothiophene
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The generality of a three-step route for the preparation of 4-Acetoxy-2-Alkyltetrahydrothiophenes was investigated, which started from 1-Alken-4-ols including epoxidation, mesylation and intramolecular nucleophilic substitution. 4-Acetoxy-2-Alkyltetrahydr
- Li, Yaxi,Ding, Rui,Liu, Yongguo,Ma, Bianbian,Sun, Baoguo,Tian, Hongyu
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p. 254 - 272
(2018/02/22)
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- Practical way for the synthesis of 3,3′-bis-substituted benzo[d][1,2]oxaphosphole 2-oxides by phosphonylation of in situ generated o-quinone methides
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Phosphonylation of the pretreated 2-(hydroxymethyl)phenol derivatives with acetic anhydride using trialkylphosphites as the nucleophilic reagents was reported, providing a practical way to the synthesis of novel highly steric 3,3′-bis-substituted benzo[d][1,2]oxaphosphole 2-oxides.
- He, Xinchun,Lv, Wenwen,Shi, Xiaomeng,Wei, Hao,Shi, Min,Wang, Feijun
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p. 1038 - 1041
(2018/02/23)
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