- Photoacid-Enabled Synthesis of Indanes via Formal [3 + 2] Cycloaddition of Benzyl Alcohols with Olefins
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An environmentally friendly and highly diastereoselective method for synthesizing indanes has been developed via a metastable-state photoacid system containing catalytic protonated merocyanine (MEH). Under visible-light irradiation, MEH yields a metastable spiro structure and liberated protons, which facilitates the formation of carbocations from benzyl alcohols, thus delivering diverse molecules in the presence of various nucleophiles. Mainly, a variety of indanes could be easily obtained from benzyl alcohols and olefins, and water is the only byproduct.
- Dong, Kui,Li, Xiang-Sheng,Liu, Qiang,Wu, Li-Zhu,Yang, Biao
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supporting information
(2022/03/17)
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- Olefination via Cu-Mediated Dehydroacylation of Unstrained Ketones
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The dehydroacylation of ketones to olefins is realized under mild conditions, which exhibits a unique reaction pathway involving aromatization-driven C-C cleavage to remove the acyl moiety, followed by Cu-mediated oxidative elimination to form an alkene between the α and β carbons. The newly adopted N′-methylpicolinohydrazonamide (MPHA) reagent is key to enable efficient cleavage of ketone C-C bonds at room temperature. Diverse alkyl- and aryl-substituted olefins, dienes, and special alkenes are generated with broad functional group tolerance. Strategic applications of this method are also demonstrated.
- Dong, Guangbin,Xu, Yan,Zhou, Xukai
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supporting information
p. 20042 - 20048
(2021/12/03)
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- Facile Synthesis of Chiral Arylamines, Alkylamines and Amides by Enantioselective NiH-Catalyzed Hydroamination
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Regio- and enantioselective hydroarylamination, hydroalkylamination and hydroamidation of styrenes have been developed by NiH catalysis with a simple bioxazoline ligand under mild conditions. A wide range of enantioenriched benzylic arylamines, alkylamines and amides can be easily accessed by nitroarenes, hydroxylamines and dioxazolones, respectively as amination reagents. The chiral induction in these reactions is proposed to proceed through an enantiodifferentiating syn-hydronickellation step.
- Meng, Lingpu,Yang, Jingjie,Duan, Mei,Wang, You,Zhu, Shaolin
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supporting information
p. 23584 - 23589
(2021/09/28)
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- Bifunctional Metal-Organic Layers for Tandem Catalytic Transformations Using Molecular Oxygen and Carbon Dioxide
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Tandem catalytic reactions improve atom- and step-economy over traditional synthesis but are limited by the incompatibility of the required catalysts. Herein, we report the design of bifunctional metal-organic layers (MOLs), HfOTf-Fe and HfOTf-Mn, consisting of triflate (OTf)-capped Hf6 secondary building units (SBUs) as strong Lewis acidic centers and metalated TPY ligands as metal active sites for tandem catalytic transformations using O2 and CO2 as coreactants. HfOTf-Fe effectively transforms hydrocarbons into cyanohydrins via tandem oxidation with O2 and silylcyanation whereas HfOTf-Mn converts styrenes into styrene carbonates via tandem epoxidation and CO2 insertion. Density functional theory calculations revealed the involvement of a high-spin FeIV (S = 2) center in the challenging oxidation of the sp3 C-H bond. This work highlights the potential of MOLs as a tunable platform to incorporate multiple catalysts for tandem transformations.
- Jiang, Xiaomin,Lan, Guangxu,Lin, Wenbin,Ni, Kaiyuan,Quan, Yangjian,Shi, Wenjie,Song, Yang,Wang, Cheng
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supporting information
p. 16718 - 16724
(2021/10/21)
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- Anti-Markovnikov hydroazidation of activated olefins via organic photoredox catalysis
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Organic azides serve as synthetically useful surrogates for primary amines, a functional group which is ubiquitous in bioactive and medicinally relevant molecules. Historically, the formal hydroazidation of simple activated olefins and styrenes has proven
- Nicewicz, David A.,Onuska, Nicholas P. R.,Rosario Collazo, José L.,Schutzbach-Horton, Megan E.
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supporting information
p. 55 - 59
(2019/12/30)
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- Visible photocatalysis of novel oxime phosphonates: Synthesis of β-aminophosphonates
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A novel type of oxime phosphonate was synthesized and used in the intermolecular cascade radical addition reaction of alkenes to access β-aminophosphonates via visible-light-driven N-centered iminyl radical-mediated and redox-neutral selective C-P single-bond cleavage in an active phosphorus radical route. The procedure is characterized by its ability to achieve the construction of Csp3-P and Csp3-N bonds without the requirement for oxidants and bases.
- Li, Yong-Hong,Wang, Chun-Hai,Gao, Su-Qian,Qi, Feng-Ming,Yang, Shang-Dong
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supporting information
p. 11888 - 11891
(2019/10/11)
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- Nickel-Catalyzed Stille Cross Coupling of C-O Electrophiles
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Aryl sulfamates, tosylates, and mesylates undergo efficient Ni-catalyzed cross coupling with diverse organostannanes in the presence of relatively unhindered alkylphosphine ligands and KF. The coupling is valuable for difficult bond constructions, such as aryl - heteroaryl, aryl - alkenyl, and aryl - alkynyl, using nontriflate phenol derivatives. A combination of experimental and computational studies implicates an unusual mechanism for transmetalation involving an 8-centered cyclic transition state. This reaction is inhibited by chloride sources due to slow transmetalation of organostannanes at a Ni(II) - chloride intermediate. These studies help to explain why prior efforts to achieve Ni-catalyzed Stille coupling of phenol derivatives were unsuccessful.
- Russell, John E. A.,Entz, Emily D.,Joyce, Ian M.,Neufeldt, Sharon R.
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p. 3304 - 3310
(2019/03/26)
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- Palladium-catalyzed salt-free double decarboxylative aryl allylation
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This report describes a palladium-catalyzed decarboxylative aryl allylation between unactivated benzoic acids and allylic carbonates. This transformation successfully couples a variety of carbonates and benzoic acids in good yield (up to 94%) using 1 mol% palladium. This salt free allyl-arylation proceeds without added base, copper, or silver. The only stoichiometric byproducts are carbon dioxide and tert-butanol.
- Daley, Ryan A.,Topczewski, Joseph J.
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supporting information
p. 1709 - 1713
(2019/02/20)
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- Tropylium-promoted carbonyl-olefin metathesis reactions
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The carbonyl-olefin metathesis (COM) reaction is a highly valuable chemical transformation in a broad range of applications. However, its scope is much less explored compared to analogous olefin-olefin metathesis reactions. Herein we demonstrate the use of tropylium ion as a new effective organic Lewis acid catalyst for both intramolecular and intermolecular COM and new ring-opening metathesis reactions. This represents a significant improvement in substrate scope from recently reported developments in this field.
- Tran, Uyen P.N.,Oss, Giulia,Pace, Domenic P.,Ho, Junming,Nguyen, Thanh V.
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p. 5145 - 5151
(2018/06/21)
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- Cobalt-Catalyzed Allylic C(sp3)-H Carboxylation with CO2
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Catalytic carboxylation of the allylic C(sp3)-H bond of terminal alkenes with CO2 was developed with the aid of a Co/Xantphos complex. A wide range of allylarenes and 1,4-dienes were successfully transformed into the linear styrylacetic acid and hexa-3,5-dienoic acid derivatives in moderate to high yields, with excellent regioselectivity. The carboxylation showed remarkable functional group tolerability, so that selective addition to CO2 occurred in the presence of other carbonyl groups such as amide, ester, and ketone. Since styrylacetic acid derivatives can be readily converted into optically active γ-butyrolactones through Sharpless asymmetric dihydroxylation, this allylic C(sp3)-H carboxylation showcases a facile synthesis of γ-butyrolactones from simple allylarenes via short steps.
- Michigami, Kenichi,Mita, Tsuyoshi,Sato, Yoshihiro
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supporting information
p. 6094 - 6097
(2017/05/08)
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- Simple synthesis method of olefin
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The invention discloses a simple synthesis method of olefin, and relates to the technical field of preparation of an organic compound, i.e., olefin. The olefin is prepared by taking tertiary alcohol as a raw material, sodium bisulfate monohydrate as a catalyst and water as a solvent. Compared with the conventional method, the method provided by the invention has the advantages that the raw materials are simple and readily available, the cost is low, the process time is short, the reaction conditions are mild, and the reaction is easy to operate; the simple synthesis method is a simple method for synthesizing an olefin compound.
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Paragraph 0012; 0019; 0020
(2017/04/28)
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- Enantiospecific intramolecular heck reactions of secondary benzylic ethers
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Enantioenriched methylenecyclopentanes are synthesized by stereospecific, nickel-catalyzed Heck cyclizations of secondary benzylic ethers. The reaction proceeds in high yield and enantiospecificity for benzylic ethers of both π-extended and simple arenes. Ethers with pendant 1,2-disubstituted olefins form trisubstituted olefins with control of both absolute configuration and alkene geometry. Diastereoselective synthesis of a polycyclic furan is demonstrated.
- Harris, Michael R.,Konev, Mikhail O.,Jarvo, Elizabeth R.
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supporting information
p. 7825 - 7828
(2014/06/23)
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- Stereospecific nickel-catalyzed cross-coupling reactions of alkyl grignard reagents and identification of selective anti-breast-cancer agents
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Alkyl Grignard reagents that contain β-hydrogen atoms were used in a stereospecific nickel-catalyzed cross-coupling reaction to form C(sp 3)-C(sp3) bonds. Aryl Grignard reagents were also utilized to synthesize 1,1-diarylalkanes. Sev
- Yonova, Ivelina M.,Johnson, A. George,Osborne, Charlotte A.,Moore, Curtis E.,Morrissette, Naomi S.,Jarvo, Elizabeth R.
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supporting information
p. 2422 - 2427
(2014/03/21)
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- Functional-group-tolerant, nickel-catalyzed cross-coupling reaction for enantioselective construction of tertiary methyl-bearing stereocenters
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The first Negishi nickel-catalyzed stereospecific cross-coupling reaction of secondary benzylic esters is reported. A series of traceless directing groups is evaluated for ability to promote cross-coupling with dimethylzinc. Esters with a chelating thioether derived from commercially available 2-(methylthio)acetic acid are most effective. The products are formed in high yield and with excellent stereospecificity. A variety of functional groups are tolerated in the reaction including alkenes, alkynes, esters, amines, imides, and O-, S-, and N-heterocycles. The utility of this transformation is highlighted in the enantioselective synthesis of a retinoic acid receptor agonist and a fatty acid amide hydrolase inhibitor.
- Wisniewska, Hanna M.,Swift, Elizabeth C.,Jarvo, Elizabeth R.
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p. 9083 - 9090
(2013/07/26)
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- Nickel-catalyzed cross-couplings of benzylic pivalates with arylboroxines: Stereospecific formation of diarylalkanes and triarylmethanes
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We have developed a stereospecific nickel-catalyzed cross-coupling of benzylic pivalates with arylboroxines. The success of this reaction relies on the use of Ni(cod)2 as the catalyst and NaOMe as a uniquely effective base. This reaction has broad scope with respect to the arylboroxine and benzylic pivalate, enabling the synthesis of a variety of diarylalkanes and triarylmethanes in good to excellent yields and ee's.
- Zhou, Qi,Srinivas, Harathi D.,Dasgupta, Srimoyee,Watson, Mary P.
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p. 3307 - 3310
(2013/04/23)
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- Stereospecific nickel-catalyzed cross-coupling reactions of alkyl ethers: Enantioselective synthesis of diarylethanes
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Secondary benzylic ethers undergo stereospecific substitution reactions with Grignard reagents in the presence of nickel catalysts. Reactions proceed with inversion of configuration and high stereochemical fidelity. This reaction allows for facile enantio
- Taylor, Buck L. H.,Swift, Elizabeth C.,Waetzig, Joshua D.,Jarvo, Elizabeth R.
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supporting information; experimental part
p. 389 - 391
(2011/04/16)
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- Oxocarbons and related compounds. Part 28. Polycycle-fused dihydrobenzocyclobutenediones and benzocyclobutenediones. Synthesis of cyclobuta[c]- and cyclobuta[a]-phenanthrene-1,2-diones and cyclobuta[a]triphenylene-11,12-dione
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The Diels-Alder reaction of semisquaric chloride 5 with 1-(alk-1-enyl)naphthalenes, 2-(alk-1-enyl)naphthalenes and 9-vinylphenanthrene is used to prepare dihydrocyclobuta[c]phenanthrene-1,2-diones 8a-c, dihydrocyclobuta[a]phenanthrene-1,2-diones 12a-c, and dihydrocyclobuta[a]triphenylene-11,12-dione 18, respectively. Treatment of the dihydrocyclobutaarenediones with bromine effects aromatization and opens up a route for the synthesis of cyclobuta[c]phenanthrene-1,2-diones 9a-c, cyclobuta[a]phenanthrene-1,2-diones 13a-c and cyclobuta[a]triphenylene-11,12-dione 19. The range of Diels-Alder reactions with semisquaric chloride 5 is extended to the use of 4-(prop-1-enyl)-1,2-dihydronaphthalene 14. Tetrahydrocyclobuta[a]phenanthrene-1,2-dione 15 is obtained in 69% yield, which can be oxidized, stepwise or at once, to give cyclobuta[a]phenanthrene-1,2-dione 13b in good yields.
- Schmidt, Arthur H.,Kircher, Gunnar,Zylla, Joerg,Veit, Stephan
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p. 409 - 414
(2007/10/03)
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- Novel Thermal Cyclisation of o-Methylstyrylalkynes to give 2-Alkenylnaphthalenes
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Formation of o-methylstyrylalkynes by flash vacuum pyrolysis of the corresponding stabilised phosphorus ylides at 900 deg C is accompanied by unexpected cyclisation to give 2-alkenylnaphthalenes and deuterium labelling has been used to elucidate the mechanisms involved.
- Aitken, R. Alan,Boeters, Christine,Morrison, John J.
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p. 1303 - 1306
(2007/10/02)
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