- Electrochemically driven catalytic Pd(0)/Cr(II) mediated coupling of organic halides with aldehydes. The Nozaki-Hiyama-Kishi reaction
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An electrochemically driven, catalytic, Pd(0)/Cr(II) mediated coupling of organic halides with aldehydes is described. The reaction proceeds under mild conditions and the influence of reaction conditions and the mechanism are briefly discussed.
- Grigg, Ronald,Putnikovic, Bogdan,Urch, Christopher J.
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Read Online
- Bio-inspired asymmetric aldehyde arylations catalyzed by rhodium-cyclodextrin self-inclusion complexes
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Transition-metal catalysts are powerful tools for carbon-carbon bond-forming reactions that are difficult to achieve using native enzymes. Enzymes that exhibit inherent selectivities and reactivities through host-guest interactions have inspired widesprea
- Asahi, Kaoru,Fujiwara, Shin-Ichi,Iwasaki, Takanori,Kambe, Nobuaki,Takahashi, Ryota,Tsuda, Susumu,Ueda, Ryoji,Yamauchi, Hiroki
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supporting information
p. 801 - 807
(2022/02/03)
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- Catalytic Aldehyde and Alcohol Arylation Reactions Facilitated by a 1,5-Diaza-3,7-diphosphacyclooctane Ligand
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We report a catalytic method to access secondary alcohols by the coupling of aryl iodides. Either aldehydes or alcohols can be used as reaction partners, making the transformation reductive or redox-neutral, respectively. The reaction is mediated by a Ni catalyst and a 1,5-diaza-3,7-diphosphacyclooctane. This P2N2ligand, which has previously been unrecognized in cross-coupling and related reactions, was found to avoid deleterious aryl halide reduction pathways that dominate with more traditional phosphines and NHCs. An interrupted carbonyl-Heck type mechanism is proposed to be operative, with a key 1,2-insertion step forging the new C-C bond and forming a nickel alkoxide that may be turned over by an alcohol reductant. The same catalyst was also found to enable synthesis of ketone products from either aldehydes or alcohols, demonstrating control over the oxidation state of both the starting materials and products.
- Isbrandt, Eric S.,Nasim, Amrah,Newman, Stephen G.,Zhao, Karen
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supporting information
p. 14646 - 14656
(2021/09/18)
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- Binaphthyl-prolinol chiral ligands: Design and their application in enantioselective arylation of aromatic aldehydes
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Binaphthyl-prolinol ligands were designed and applied in enantioselective arylation of aromatic aldehydes and sequential arylation-lactonization of methyl 2-formylbenzoate. Under optimized conditions, the reactions provided the desired diarylmethanols and 3-aryl phthalides in up to 96% yields with up to 99% ee and up to 89% yields with up to 99% ee, respectively. In particular, essentially optically pure 3-aryl phthalides (over 99% ee) were obtained in large quantities through recrystallization. This journal is
- Yao, Chao,Chen, Yaoqi,Sun, Ruize,Wang, Chao,Huang, Yue,Li, Lin,Li, Yue-Ming
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supporting information
p. 3644 - 3655
(2021/05/04)
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- Asymmetric Deoxygenative Cyanation of Benzyl Alcohols Enabled by Synergistic Photoredox and Copper Catalysis?
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Summary of main observation and conclusion. An enantioselective deoxygenative cyanation of benzyl alcohols was accomplished for the first time through the synergistic photoredox and copper catalysis. This reaction features the use of organic photosensitizer and low-cost 3d metal catalyst, simple and safe operations, and extremely mild conditions. A variety of chiral benzyl nitriles were produced in generally good yields and high level of enantiocontrols from readily available feedstocks (22 examples, up to 93% yield and 92% ee).
- Chen, Hong-Wei,Lu, Fu-Dong,Cheng, Ying,Jia, Yue,Lu, Liang-Qiu,Xiao, Wen-Jing
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supporting information
p. 1671 - 1675
(2020/11/03)
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- Bulky N-Heterocyclic-Carbene-Coordinated Palladium Catalysts for 1,2-Addition of Arylboron Compounds to Carbonyl Compounds
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The synthesis of primary, secondary, and tertiary alcohols by the 1,2-addition of arylboronic acids or boronates to carbonyl compounds, including unactivated ketones, using novel bulky yet flexible N-heterocyclic carbene (NHC)-coordinated 2,6-di(pentan-3-yl)aniline (IPent)-based cyclometallated palladium complexes (CYPs) as catalysts is reported. The PhS-IPent-CYP-catalyzed reactions are efficient at low catalyst loadings (0.02–0.3 mol% Pd), and the exceptional catalytic activity for 1,2-addition is attributed to the steric bulk of the NHC ligand. These reactions can yield a wide range of functionalized benzylic alcohols that are difficult to synthesize by classical protocols using highly active organomagnesium or lithium reagents.
- Okuda, Yuta,Nagaoka, Masahiro,Yamamoto, Tetsuya
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p. 6291 - 6300
(2020/11/30)
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- Transition-Metal-Free Reductive Functionalization of Tertiary Carboxamides and Lactams for α-Branched Amine Synthesis
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A new method for the synthesis of α-branched amines by reductive functionalization of tertiary carboxamides and lactams is described. The process relies on the efficient and controlled reduction of tertiary amides by a sodium hydride/sodium iodide composite, in situ treatment of the resulting anionic hemiaminal with trimethylsilyl chloride and subsequent coupling with nucleophilic reagents including Grignard reagents and tetrabutylammonium cyanide. The new method exhibits broad functional-group compatibility, operates under transition-metal-free reaction conditions, and is suitable for various synthetic applications on both sub-millimole and on multigram scales.
- Chiba, Shunsuke,Dixon, Darren J.,Fan, Dongyang,Ong, Derek Yiren
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supporting information
p. 11903 - 11907
(2020/05/22)
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- Nickel Catalyzed Intermolecular Carbonyl Addition of Aryl Halide
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In this study, we develop a nickel-catalyzed carbonyl arylation reaction employing aldehydes with aryl and allyl halides. Various aryl, α,β-unsaturated aldehyde and aliphatic aldehydes can be converted into their corresponding secondary alcohols in moderate-to-high yields. In addition, we extended this approach to develop an asymmetric reductive coupling reaction that combines nickel salts with chiral bisoxazoline ligands to give secondary alcohols with moderate enantioselectivity.
- Ishida, Seima,Suzuki, Hiroyuki,Uchida, Seiichiro,Yamaguchi, Eiji,Itoh, Akichika
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supporting information
p. 7483 - 7487
(2019/12/11)
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- Combined Photoredox/Enzymatic C?H Benzylic Hydroxylations
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Chemical transformations that install heteroatoms into C?H bonds are of significant interest because they streamline the construction of value-added small molecules. Direct C?H oxyfunctionalization, or the one step conversion of a C?H bond to a C?O bond, could be a highly enabling transformation due to the prevalence of the resulting enantioenriched alcohols in pharmaceuticals and natural products,. Here we report a single-flask photoredox/enzymatic process for direct C?H hydroxylation that proceeds with broad reactivity, chemoselectivity and enantioselectivity. This unified strategy advances general photoredox and enzymatic catalysis synergy and enables chemoenzymatic processes for powerful and selective oxidative transformations.
- Betori, Rick C.,May, Catherine M.,Scheidt, Karl A.
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supporting information
p. 16490 - 16494
(2019/11/03)
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- Asymmetric Hydrophosphination of Heterobicyclic Alkenes: Facile Access to Phosphine Ligands for Asymmetric Catalysis
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Asymmetric hydrophosphination is the most atomically economical and straightforward approach to the construction of chiral organophosphorus compounds. Good stereoselectivities have been achieved in asymmetric hydrophosphination of an electron-deficient C=
- Lu, Zhiwu,Zhang, Haoyang,Yang, Zhiping,Ding, Ning,Meng, Ling,Wang, Jun
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p. 1457 - 1463
(2019/02/01)
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- Super electron donor-mediated reductive desulfurization reactions
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The desulfurization of thioacetals and thioethers by a pyridine-derived electron donor is described. This methodology provides efficient access to the reduced products in high yields and does not require the use of transition-metals, elemental alkali-metals, or hydrogen atom donors.
- Nozawa-Kumada, Kanako,Ito, Shungo,Noguchi, Koto,Shigeno, Masanori,Kondo, Yoshinori
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supporting information
p. 12968 - 12971
(2019/11/05)
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- C2-Symmetric Hindered "sandwich" Chiral N-Heterocyclic Carbene Precursors and Their Transition Metal Complexes: Expedient Syntheses, Structural Authentication, and Catalytic Properties
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We present here a new family of C2-symmetric "sandwich" NHC ligands abbreviated as SITLAr and BzITLAr and their complexes. The chiral fragments incorporate bulky yet flexible cyclohexyl groups with α-stereocenters joined to nitrogens individually, which set up chiral pockets around pivotal carbene carbons (less than 2.5 ?). Full characterization revealed unique structures with roughly parallel aryl moieties above and below imidazoline and benzimidazole planes in the Z-shaped arrangement. Extra hydrogen bonding interactions and steric stress between the square-planar frameworks and aryl groups led to the exceptional confinement and reversed the configurations in the iridium complexes. In accordance with Tolman's electronic parameters and topographic steric maps of well-established metalated complexes, these new ligands possess strong electron-donating properties and exceptionally steric demands. Additionally, the preliminary results employing the BzITLAr ligands allowed appropriate activities and provided potential applications for asymmetric induction in the enantioselective aryl transfer and hydrosilylation reactions with moderate enantioselectivity.
- Liu, Cong,Shen, Hong-Qiang,Chen, Mu-Wang,Zhou, Yong-Gui
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supporting information
p. 3756 - 3769
(2018/10/20)
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- Employing Arynes for the Generation of Aryl Anion Equivalents and Subsequent Reaction with Aldehydes
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Arynes are highly reactive intermediates, which are utilized for the electrophilic arylation of various X-H bonds (X = O, N, S etc.). Herein, a new synthetic strategy is demonstrated, where arynes are converted into aryl anion equivalents by treatment with phosphines and a base. The addition of phosphines to arynes form the phosphonium salts, which in the presence of a carbonate base generates the aryl anion equivalent. Subsequent addition of the aryl anions with aldehydes afforded the secondary alcohols.
- Gaykar, Rahul N.,Bhunia, Anup,Biju, Akkattu T.
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p. 11333 - 11340
(2018/07/21)
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- Control of tandem isomerizations: Flow-assisted reactions of: O -lithiated aryl benzyl ethers
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Tandem chemical changes are often difficult to control at will, because they proceed rapidly through multiple unstable reactive intermediates. It is desirable to develop a novel method for controlling such tandem changes to obtain desired products with high selectivity. Herein, we report a flow microreactor platform for controlling tandem isomerizations of o-lithiated aryl benzyl ethers based on precise residence time control.
- Lee, Hyune-Jea,Kim, Heejin,Yoshida, Jun-Ichi,Kim, Dong-Pyo
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supporting information
p. 547 - 550
(2018/01/19)
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- [Ir(COD)Cl]2/tris(2,4-di-t-butylphenyl)phosphite-catalyzed addition reactions of arylboronic acids with aldehydes
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[Ir(COD)Cl]2/tris(2,4-di-t-butylphenyl)phosphite-catalyzed addition reactions of arylboronic acids with aldehydes were described. The Ir(I) catalyst, generated from [Ir(COD)Cl]2 and tris(2,4-di-t-butylphenyl)phosphite, was an efficient catalyst system for the addition reactions of a variety of arylboronic acids with aromatic and aliphatic aldehydes. The easy availability of the catalyst and good yields make these reactions potentially useful in organic synthesis.
- Liao, Yuan-Xi,Dong, Jie,Hu, Qiao-Sheng
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supporting information
p. 1548 - 1550
(2018/03/26)
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- Chiral terpene auxiliaries IV: new monoterpene PHOX ligands and their application in the catalytic asymmetric transfer hydrogenation of ketones
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New PHOX ligands, derived in three steps from (1R, 2S, 3R, 5R)-3-amino-apopinan-2-ol 1 and (1R, 2R, 3S, 5R)-3-amino-pinan-2-ol 2 were applied as chiral ligands for the formation of ruthenium catalysts. The catalysts were used in asymmetric transfer hydrogenations of prochiral ketones producing the corresponding alcohols in moderate to high yields and enantioselectivity.
- Kmieciak, Anna,Krzemiński, Marek P.
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p. 467 - 472
(2017/03/24)
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- Chiral thiophosphoramide catalyzed asymmetric aryl transfer reactions for the synthesis of functional diarylmethanols
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In this investigation, chiral thiophosphoramide 3d was easily prepared from chiral (1R,2R)-1,2-diphenylethylenediamine and then applied as an efficient chiral ligand in the catalytic asymmetric arylation reactions of various aromatic aldehydes. The corresponding diarylmethanol products were produced with good to excellent yields (up to 98%) and enantioselectivities (up to 94%). The recovery of chiral ligand 3d could be as high as 96%.
- Wang, Yabai,Zong, Hua,Huang, Huayin,Song, Ling
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- AlCl3 catalyzed coupling of: N-benzylic sulfonamides with 2-substituted cyanoacetates through carbon-nitrogen bond cleavage
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A new cross-coupling reaction of N-benzylic sulfonamides with 2-substituted cyanoacetates for the synthesis of 2-substituted benzylbenzene was reported. In the presence of AlCl3, a broad range of N-benzylic sulfonamides reacted smoothly with 2-substituted cyanoacetates to afford structurally diverse benzylbenzenes in moderate to excellent yields. The conversion could be enlarged to gram-scale efficiently. The practicability of this approach was further manifested in the synthesis of a related bioactive agent with high anti-inflammatory activity.
- Hu, Chen,Hong, Gang,Qian, Xiaofei,Kim, Kwang Rim,Zhu, Xiaoyan,Wang, Limin
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supporting information
p. 4984 - 4991
(2017/07/10)
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- Exploring the Reactivity of α-Lithiated Aryl Benzyl Ethers: Inhibition of the [1,2]-Wittig Rearrangement and the Mechanistic Proposal Revisited
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By carefully controlling the reaction temperature, treatment of aryl benzyl ethers with tBuLi selectively leads to α-lithiation, generating stable organolithiums that can be directly trapped with a variety of selected electrophiles, before they can undergo the expected [1,2]-Wittig rearrangement. This rearrangement has been deeply studied, both experimentally and computationally, with aryl α-lithiated benzyl ethers bearing different substituents at the aryl ring. The obtained results support the competence of a concerted anionic intramolecular addition/elimination sequence and a radical dissociation/recombination sequence for explaining the tendency of migration for aryl groups. The more favored rearrangements are found for substrates with electron-poor aryl groups that favor the anionic pathway.
- Velasco, Rocío,Silva López, Carlos,Nieto Faza, Olalla,Sanz, Roberto
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supporting information
p. 15058 - 15068
(2016/10/11)
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- Kinetic resolution of secondary carbinols by a chiral N,N-4-dimethylaminopyridine derivative containing a 1,1′-binaphthyl unit: Hydrogen bonding affects catalytic activity and enantioselectivity
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We developed an acylative kinetic resolution of secondary carbinols using a binaphthyl-based N,N-4-dimethylaminopyridine (DMAP) derivative 1d with tert-Alcohol substituents. The reaction proceeded with a wide range of carbinols with moderate to high selectivity (s) (up to s = 79.5). Kinetic studies revealed that catalyst 1d was more catalytically active than the corresponding bis-methyl ether 1d′ or DMAP. Hydrogen bonding between tert-Alcohols of the catalyst and secondary carbinols was responsible for the enhanced reaction rate and high enantioselectivity.
- Fujii, Kazuki,Mitsudo, Koichi,Mandai, Hiroki,Suga, Seiji
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p. 1081 - 1092
(2016/10/11)
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- Catalytic Asymmetric Addition of Organolithium Reagents to Aldehydes
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Herein we report an efficient catalytic system for the titanium-promoted enantioselective addition of organolithium reagents to aldehydes, based on chiral Ar-BINMOL ligands. Unprecedented yields and enantioselectivities are achieved in the alkylation reactions of aliphatic aldehydes. Remarkably, methyllithium can be added to a wide variety of aromatic and aliphatic aldehydes, providing versatile chiral methyl carbinol units in a simple one-pot procedure under mild conditions and in very short reaction times.
- Veguillas, Marcos,Solà, Ricard,Shaw, Luke,Maciá, Beatriz
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p. 1788 - 1794
(2016/04/05)
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- Enantioselective addition of organozinc reagents to carbonyl compounds catalyzed by a camphor derived chiral γ-amino thiol ligand
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In this article, the design and synthesis of the chiral camphor derived γ-amino thiol ligand 17 and its application in catalytic enantioselective carbon-carbon forming reactions through the addition of organozinc reagents to carbonyl compounds is described. The catalytic activity and enantioselectivity of ligand 17 is demonstrated in the enantioselective addition of various organozinc reagents to aldehydes and ketoesters, offering the corresponding alcohols in high yields and enantioselectivities. The role of the mercapto group in the highly enantioselective 1,2-addition reaction of organozincs to aldehyde is also discussed.
- Wu, Hsyueh-Liang,Wu, Ping-Yu,Cheng, Ying-Ni,Uang, Biing-Jiun
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p. 2656 - 2665
(2016/05/10)
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- Synthesis of new benzimidazolium salts and their application in the asymmetric arylation of aldehydes
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A series of novel chiral benzimidazolium salts, the precursor of N-heterocyclic carbene ligands, were designed and synthesized from 1,2-dibromobenzene. In situ prepared corresponding carbenes were tested in asymmetric Rh-catalyzed arylation of aromatic aldehydes, affording chiral diarylmethanols with high yields and moderate enantioselectivities.
- He, Wei-Ping,Zhou, Bi-Hui,Zhou, Ya-Li,Li, Xiang-Rong,Fan, Li-Mei,Shou, Hao-Wen,Li, Jie
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supporting information
p. 3152 - 3155
(2016/07/06)
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- Putting corannulene in its place. Reactivity studies comparing corannulene with other aromatic hydrocarbons
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A series of aromatic hydrocarbons were investigated so as to compare the reactivity of corannulene with planar aromatic hydrocarbons. Corannulene was found to be more reactive than benzene, naphthalene and triphenylene to Friedel-Crafts acylation whilst electrophilic aromatic bromination was also used to confirm that triphenylene was less reactive than corannulene and that pyrene, perylene and acenaphthene were more so. The stabilisation of a neighbouring carbocation by the various aromatic systems was investigated through consideration of the rates of methanolysis of a series of benzylic alcohols. The reactivity series was found to parallel that observed for the electrophilic aromatic substitutions and both series are supported by computational studies. As such, a reactivity scale was devised that showed that corannulene was less reactive than would be expected for an aromatic planar species of similar pi electron count.
- George, Stephen R. D.,Frith, Thomas D. H.,Thomas, Donald S.,Harper, Jason B.
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p. 9035 - 9041
(2015/09/01)
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- The carbonyl group tuned electron-deficient phosphorus ligands and their application in Rhodium catalyzed arylation to aldehydes
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Acylphosphines, which could be efficiently prepared from acid chlorides and secondary phosphines, were developed as a type of carbonyl group tuned electron-deficient phosphorus ligand. They were found to be a kind of efficient ligand in Rhodium catalyzed arylation to aldehydes through accelerating the transmetalation process. Chiral acylphosphine ligands could be generated from carboxylic acids bearing the chiral framework correspondingly.
- Yang, Jiefang,Chen, Xingyu,Wang, Zhiqian
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supporting information
p. 5673 - 5675
(2015/09/15)
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- MELANIN PRODUCTION INHIBITOR
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Disclosed is a melanin production inhibitor which has an excellent inhibitory activity on the production of melanin and is highly safe. The melanin production inhibitor is represented by general formula (1) (excluding clotrimazole) and/or a pharmacologically acceptable salt thereof. In the formula, A1, A2 and A3 are independently selected from a hydrogen atom, an aryl group which may have a substituent, and an aromatic heterocyclic group which may have a substituent. At least one of A1, A2 and A3 is selected from the aryl group and the aromatic heterocyclic group, the total number of carbon atoms contained in A1, A2 and A3 is 6 to 50 and, when at least two of A1, A2 and A3 represent the aryl groups or the aromatic heterocyclic groups, the adjacent two aryl or aromatic heterocyclic groups may be bound to each other via an alkyl chain or an alkenyl chain to form a ring; m represents an integer of 0 to 2; X represents a hetero atom, a hydrogen atom, or a carbon atom; R1 and R2 are independently selected from a hydrogen atom and an oxo group. When one of R1 and R2 is an oxo group, the other is not present. R3 is selected from a hydrogen atom, and a C1-8 hydrocarbon group in which one or some of hydrogen atoms or carbon atoms may be substituted by a hetero atom or hetero atoms. The number of R3's present in the compound corresponds to X and, when two or more R3's are present, the R3's are independently present and the adjacent two R3's may be bound to each other to form, together with X, a ring, and the terminal of R3 may be bound to a carbon atom to which A1, A2 and A3 are bound, thereby forming a ring.
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Paragraph 0220 - 0223
(2015/12/17)
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- Enantioselective synthesis of α-phenyl- and α-(dimethylphenylsilyl)alkylboronic esters by ligand mediated stereoinductive reagent-controlled homologation using configurationally labile carbenoids
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Chain extension of boronic esters by the action of configurationally labile racemic lithium carbenoids in the presence of scalemic bisoxazoline ligands was explored for the enantioselective synthesis of the two title product classes. Enantioenriched 2° carbinols generated by oxidative work-up (NaOOH) of initial α-phenylalkylboronate products were obtained in 35-83% yield and 70-96% ee by reaction of B-alkyl and B-aryl neopentyl glycol boronates with a combination of O-(α-lithiobenzyl)-N,N-diisopropylcarbamate and ligand 3,3-bis[(4S)-4,5-dihydro-4-isopropyloxazol-2-yl] pentane in toluene solvent (-78 °C to rt) with MgBr2·OEt2 additive. Enantioenriched α-(dimethylsilylphenylsilyl)alkylboronates were obtained in 35-69% yield and 9-57% ee by reaction of B-alkyl pinacol boronates with a combination of lithio(dimethylphenylsilyl)methyl 2,4,6-triisopropylbenzoate and ligand 2,2-bis[(4S)-4,5-dihydro-4-isopropyloxazol-2-yl]propane in cumene solvent (-45 °C to -95 °C to rt). The stereochemical outcome of the second type of reaction depended on the temperature history of the organolithium·ligand complex indicating that the stereoinduction mechanism in this case involves some aspect of dynamic thermodynamic resolution. This journal is
- Barsamian, Adam L.,Wu, Zhenhua,Blakemore, Paul R.
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p. 3781 - 3786
(2015/03/30)
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- Enantioselective addition of ArTi(OiPr)3 to aldehydes catalyzed by a titanium complex of an N-sulfonylated amino alcohol
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Asymmetric additions of ArTi(OiPr)3 to aldehydes catalyzed by a titanium catalyst of N-sulfonylated amino alcohols were reported, and results showed that the chiral N-sulfonylated amino alcohol with two stereogenic centers could catalyze the asymmetric addition of ArTi(OiPr)3 to aldehydes to afford desired secondary alcohols in good yields with good to excellent enantioselectivities of up to 95% ee.
- Chang, Shih-Ju,Zhou, Shuangliu,Gau, Han-Mou
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p. 9368 - 9373
(2015/02/19)
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- Palladium-catalyzed arylation of aldehydes with bromo-substituted 1,3-diaryl-imidazoline carbene ligand
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The combination of 0 valent palladium precursor and bromo-substituted 1,3-diaryl-imidazoline carbene ligand precursor such as 1-(2-bromophenyl)-3-(2,6-diisopropylphenyl)-imidazolinium chloride 1a exhibited high catalytic activity for the 1,2-addition of arylboronic acids to aldehydes including aqueous formaldehyde.
- Yamamoto, Tetsuya,Furusawa, Takuma,Zhumagazin, Azamat,Yamakawa, Tetsu,Oe, Yohei,Ohta, Tetsuo
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- Solvent control of product diversity in palladium-catalyzed addition of arylboronic acid to aryl aldehydes
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In Pd-catalyzed arylboronic acid addition to aryl aldehydes, the expected carbinol or asymmetrical ether can be obtained as the major product by altering aqueous solvent composition. Exploiting this methodology with 2-formylbiphenyls as reaction partner, a fluorene scaffold can be readily constructed in two steps.
- Das, Tuluma,Chakraborty, Amarnath,Sarkar, Amitabha
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supporting information
p. 5174 - 5178
(2014/12/10)
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- Synthesis of triarylmethanes by palladium-catalyzed c-h/c-o coupling of oxazoles and diarylmethanol derivatives
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A PdCl2(MeCN)2/PPhCy2 catalyst couples oxazoles with diarylmethyl carbonates or pivalates to form the corresponding triarylmethanes in good yields. The catalysis involves successive secondary benzylic sp3 C-O and heteroaromatic sp2 C-H cleavages and provides an effective access to heteroarene-containing triarylmethanes from nonhalogenated and nonmetalated starting materials, which is complementary to precedented cross-coupling technologies with organic halides and organometallic reagents.
- Tabuchi, Sho,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
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p. 5401 - 5411
(2014/07/08)
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- Synthesis of enantiomerically enriched triarylmethanes by enantiospecific suzuki-miyaura cross-coupling reactions
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The Suzuki-Miyaura cross-coupling of chiral, enantiomerically enriched dibenzylic boronic esters is described. The reaction proceeds with almost complete retention of stereochemistry, providing access to triarylmethanes, compounds that have high biologica
- Matthew, Smitha C.,Glasspoole, Ben W.,Eisenberger, Patrick,Crudden, Cathleen M.
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p. 5828 - 5831
(2014/05/20)
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- A chiral ruthenium-monophosphine catalyst for asymmetric addition of arylboronic acids to aryl aldehydes
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A novel ruthenium catalyst on the basis of a chiral monophosphorus ligand is efficient for the asymmetric addition of arylboronic acids to aryl aldehydes, providing a series of chiral diarylmethanols in excellent yields and enantioselectivities (up to 92% ee). Preliminary study has shown that this process is catalyzed by a Ru complex with a single monophosphorus ligand.
- Li, Ke,Hu, Naifu,Luo, Renshi,Yuan, Weicheng,Tang, Wenjun
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p. 6350 - 6355
(2013/07/26)
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- Retention or inversion in stereospecific nickel-catalyzed cross-coupling of benzylic carbamates with arylboronic esters: Control of absolute stereochemistry with an achiral catalyst
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Stereospecific coupling of benzylic carbamates and pivalates with aryl- and heteroarylboronic esters has been developed. The reaction proceeds with selective inversion or retention at the electrophilic carbon, depending on the nature of the ligand. Tricyclohexylphosphine ligand provides the product with retention, while an N-heterocyclic carbene ligand provides the product with inversion.
- Harris, Michael R.,Hanna, Luke E.,Greene, Margaret A.,Moore, Curtis E.,Jarvo, Elizabeth R.
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supporting information
p. 3303 - 3306
(2013/04/10)
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- Catalytic asymmetric addition of alkyllithium reagents to aromatic aldehydes
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Herein, we report the first efficient catalytic system for the asymmetric alkylation of aldehydes with organolithium reagents in the presence of titanium(IV) isopropoxide. A variety of alkyllithium reagents can be added to aromatic aldehydes in good yields with high enantioselectivities in a simple one-pot procedure under mild conditions. Herein, we report the first efficient catalytic system for the asymmetric alkylation ofaldehydes with organolithium reagents in the presence of titanium(IV) isopropoxide. A variety of alkyllithium reagents can be added to aromatic aldehydes in good yields with high enantioselectivities in a simple one-pot procedure under mild conditions. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
- Fernandez-Mateos, Emilio,MacIa, Beatriz,Yus, Miguel
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supporting information; body text
p. 3732 - 3736
(2012/09/21)
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- Preparation and catalytic performances of a molecularly imprinted RU-complex catalyst with an NH2 binding site on a SiO2 surface
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A catalyst surface with an active metal site, a shape-selective reaction space, and an NH2 binding site for o-fluorobenzophenone was designed and prepared by the molecular imprinting of a supported metal complex on a SiO2 surface. A ligand of a SiO2-supported Ru complex that has a similar shape to the product of o-fluorobenzophenone hydrogenation was used as a template. An NH2 binding site for o-fluorobenzophenone was spatially arranged on the wall of a molecularly imprinted cavity with a similar shape to the template. The structures of the SiO2-supported and molecularly imprinted Ru catalysts were characterized in a step-by-step manner by means of solid-state magic angle spinning (MAS) NMR, XPS, UV/Vis, N 2 adsorption, XRF, and Ru K-edge EXAFS. The molecularly imprinted Ru catalyst exhibited excellent shape selectivity for the transfer hydrogenation of benzophenone derivatives. It was found that the NH2 binding site on the wall of the molecularly imprinted cavity enhanced the adsorption of o-fluorobenzophenone, of which the reduction product was imprinted, whereas there was no positive effect in the case of o-methylbenzophenone, which cannot interact with the NH2 binding site through hydrogen bonding. Tailoring a pocket: A molecularly imprinted Ru-complex catalyst with an NH 2 binding site for o-fluorobenzophenone has been successfully designed and prepared on a SiO2 surface for shape-selective transfer hydrogenation (see scheme). Copyright
- Yang, Yong,Weng, Zhihuan,Muratsugu, Satoshi,Ishiguro, Nozomu,Ohkoshi, Shin-Ichi,Tada, Mizuki
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experimental part
p. 1142 - 1153
(2012/03/26)
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- Kinetic resolution of diarylmethanols using a mutated variant of lipase CALB
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An enzymatic kinetic resolution of diarylmethanols via acylation has been developed. This was achieved by the use of a mutated variant of CALB that accepts larger substrates compared to the wild type. By the use of diarylmethanols with two differently sized aryl groups, enantioselective transformations were achieved. A larger size-difference led to a higher enantioselectivity. In addition, substrates with electronically different aryl groups, such as phenyl and pyridyl, also gave an enantioselective reaction. The highest E value was observed with a substrate where steric and electronic effects were combined.
- Engstr?m, Karin,Vallin, Michaela,Hult, Karl,B?ckvall, Jan-E.
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body text
p. 7613 - 7618
(2012/09/07)
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- METHOD FOR SYNTHESIS OF SECONDARY ALCOHOLS
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A method for synthesis of secondary alcohols is provided for pharmaceutical secondary alcohol by addition of organoboronic acids with aldehydes in presence of the cobalt ion and bidentate ligands as the catalyst. In addition, an enantioselective synthesis method for secondary alcohols is also herein provided in the present invention. The present invention has advantages in using less expensive cobalt ion and commercially available chiral ligands as the catalyst, wide scope of organoboronic acids and aldehydes compatible with this catalytic reaction and achieving excellent yields and/or enantiomeric excess.
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Page/Page column 2
(2012/06/16)
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- Synthesis of enantioenriched triarylmethanes by stereospecific cross-coupling reactions
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Coupling with inversion: Chiral diarylmethanol derivatives undergo a stereospecific nickel-catalyzed cross-coupling reaction with aryl Grignard reagents (see scheme). The reaction proceeds with inversion of configuration and high enantiospecificity. The m
- Taylor, Buck L. H.,Harris, Michael R.,Jarvo, Elizabeth R.
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supporting information; experimental part
p. 7790 - 7793
(2012/10/08)
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- Catalytic enantioselective addition of organoaluminum reagents to aldehydes
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An efficient catalyst for the asymmetric addition of organoaluminum reagents to aldehydes is presented. The system is based on a readily available binaphthyl derivative as a chiral ligand and an excess of titanium tetraisopropoxide. The asymmetric methylation, ethylation, and propylation of a wide variety of aromatic and aliphatic aldehydes proceeded with good yields and with high enantioselectivities in a simple one-pot procedure under mild conditions.
- Fernandez-Mateos, Emilio,MacIa, Beatriz,Yus, Miguel
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experimental part
p. 789 - 794
(2012/09/05)
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- CAMPHOR-DERIVED COMPOUNDS, METHOD FOR MANUFACTURING THE SAME, AND APPLICATION THEREOF
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Camphor-derived compounds are disclosed, which are represented as the following formula (I): wherein R1, R2, R3, and R4 each are defined as described in the specification. In addition, a method for manufacturing the camphor-derived compounds and application thereof are disclosed.
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Page/Page column 16-17
(2012/04/05)
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- PROCESS FOR PRODUCING OPTICALLY ACTIVE ALCOHOL
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Disclosed is a method for producing an optically active alcohol including reacting a titanium compound, an aromatic magnesium compound and a carbonyl compound in the presence of an optically active biphenol compound having a predetermined structure and an ether compound having a predetermined structure.
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Page/Page column 23
(2012/02/14)
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- Synthesis of fluorenone derivatives through Pd-catalyzed dehydrogenative cyclization
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Palladium-catalyzed dual C-H functionalization of benzophenones to form fluorenones by oxidative dehydrogenative cyclization is reported. This method provides a concise and effective route toward the synthesis of fluorenone derivatives, which shows outstanding functional group compatibility.
- Li, Hu,Zhu, Ru-Yi,Shi, Wen-Juan,He, Ke-Han,Shi, Zhang-Jie
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supporting information
p. 4850 - 4853,4
(2012/12/12)
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- Chiral terpene auxiliaries II. Spiroborate esters derived from α-pinene - New catalysts for asymmetric borane reduction of prochiral ketones
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New spiroborate esters derived from (1R,2R,3S,5R)-3-aminopinan-2-ol and ethylene glycol, propane-1,3-diol, pinacol, catechol, (1S,2S,3R,5S)-pinane-2,3- diol, and (1R,2R,3S,5R)-pinane-2,3-diol were used as catalysts in the borane reduction of acetophenone and other prochiral aryl alkyl ketones producing the corresponding alcohols in high yields. The influence of the spiroborate structure on the enantioselectivity and configuration of the product alcohols was examined.
- Krzemiński, Marek P.,?wiklińska, Marta
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experimental part
p. 3919 - 3921
(2011/08/09)
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- Instantaneous room-temperature and highly enantioselective ArTi(O-i-Pr)3 additions to aldehydes
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Direct asymmetric additions of ArTi(O-i-Pr)3 to aldehydes catalyzed by a titanium catalyst of (R)-H8-BINOL are reported. The reactions proceed instantaneously at room temperature, affording alcohols in ≥90% ee. Importantly, the ArTi(O-i-Pr)3 reagent differentiates the ligand effectiveness in an order of H8-BINOL > BINOL > TADDOL > diol 3 > disulfonamide 2.
- Wu, Kuo-Hui,Zhou, Shuangliu,Chen, Chien-An,Yang, Mao-Chi,Chiang, Ruei-Tang,Chen, Chi-Ren,Gau, Han-Mou
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scheme or table
p. 11668 - 11670
(2011/11/29)
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- Asymmetric additive-free aryl addition to aldehydes using perhydrobenzoxazines as ligands and boroxins as aryl source
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A highly efficient enantioselective aryl addition to aldehydes using boroxins as aryl source and conformationally restricted perhydro-1,3- benzoxazines as ligands is reported. Both enantiomeric forms of chiral arylphenylmethanols and 1,1′-disubstituted diarylmethanols are afforded with excellent yields and enantioselectivities using the same ligand by means of an appropriate combination of boroxin and aromatic aldehyde. The enantiocontrol is not significantly influenced by electronic effects or steric hindrance, even with substituted boroxins. Very homogeneous ee's are reached when substituted arylboroxins are employed, without the use of any class of additive or pre-treatment.
- Infante, Rebeca,Nieto, Javier,Andres, Celia
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experimental part
p. 6691 - 6699
(2011/11/04)
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- Catalytic enantioselective aryl transfer to aldehydes using chiral 2,2'-bispyrrolidine-based salan ligands
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Chiral C2-symmetric diamines have emerged as versatile auxiliaries or ligands in numerous asymmetric transformations. Chiral 2,2'-bispyrrolidine-based salan ligands were prepared and applied to the asymmetric aryl transfer to aldehydes with arylboronic acids as the source of transferable aryl groups. The corresponding diarylmethanols were obtained in high yields with moderate to good enantioselectivitives of up to 83% ee.
- Jia, Xuefeng,Lin, Aijun,Mao, Zhijie,Zhu, Chengjian,Cheng, Yixiang
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experimental part
p. 2971 - 2981
(2011/05/19)
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- CuCl/bipyridine-catalyzed addition reactions of arylboroxines with aldehydes, α,β-unsaturated ketones, and N-tosyl aldimines
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CuCl/bipyridine-catalyzed addition reactions of arylboroxines with aldehydes and α,β-unsaturated ketones at elevated temperatures were described. By using the microwave energy, CuCl/bipyridine-catalyzed addition reactions of arylboroxines with aldimines were also realized.
- Liao, Yuan-Xi,Hu, Qiao-Sheng
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experimental part
p. 7602 - 7607
(2011/11/12)
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- Selective arylation of aldehydes with di-rhodium(II)/NHC catalysts
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Here is described the preparation of four new rhodium(II) complexes bearing axial NHC ligands. The presence of electron-withdrawing bridging ligands resulted in an enhanced reactivity in the arylation of aldehydes with boronic acids when compared with the tetraacetate counterparts. Complex 15 (Rh 2tfa4(IPr)2) proved to be the most active catalyst for this transformation allowing the selective conversion of aromatic, aliphatic and vinyl aldehydes into the respective alcohols in excellent yields. It was demonstrated that the good group tolerance could be further extended to aromatic and conjugated ketones. DFT calculations carried out on this system showed the complementarily of the bridging ligands and axial ligand in these dinuclear complexes. It was also disclosed that Rh(II)/NHC catalytic system can promote the racemization of 1-phenyl ethanol.
- Trindade, Alexandre F.,André, Vania,Duarte, M. Teresa,Veiros, Luís F.,Gois, Pedro M.P.,Afonso, Carlos A.M.
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supporting information; experimental part
p. 8494 - 8502
(2010/11/18)
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- Palladium-imidazolinium carbene-catalyzed arylation of aldehydes with arylboronic acids in water
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The catalytic arylation of aldehydes with arylboronic acids in only water was found to be achieved using the palladium/thioether-imidazolinium chloride system in good to excellent yields. This catalytic process showed high tolerance for a broad range of substrates, giving a variety of carbinol derivatives with 2.0-3.0 mol % of the catalyst.
- Kuriyama, Masami,Ishiyama, Natsuki,Shimazawa, Rumiko,Onomura, Osamu
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experimental part
p. 6814 - 6819
(2010/10/02)
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- Cobalt-catalyzed addition reaction of organoboronic acids with aldehydes: Highly enantioselective synthesis of diarylmethanols
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Predicted outcomes: The addition reaction of organoboronic acids with aldehydes in the presence of K2CO3 catalyzed by CoI 2/ACHTUNGRE(R,R)-BDPP gives chiral secondary alcohols in excellent yields with 90-99 % enantiomeric excess (see scheme; (R,R)-BDPP = (2R,4R)-(+)-2,4-bis(diphenyl-phosphino)pentane). This method provides an alternative to prepare an R and S enantiomeric pair by using the same chiral ligand and allows the stereochemical outcome of the reaction to be predicted.
- Karthikeyan, Jaganathan,Jeganmohan, Masilamani,Cheng, Chien-Hong
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supporting information; experimental part
p. 8989 - 8992
(2010/10/02)
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