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Ligand-Controlled Copper-Catalyzed Highly Regioselective Difluoromethylation of allylic Chlorides/Bromides and Propargyl Bromides

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Chinese Journal of Chemistry 2018年第1期36卷 55-58页

作者： Yang Gu Changhui Lu Yucheng Gu Qilong Shen Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic Chemistry University of Chinese Academy Sciences Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China Syngenta Jealott's Hill International Research Cente Bracknell Berkshire RG42 6EY UK

Highly regiodivergent copper-catalyzed allylic/propargylic difluoromethylation reactions by employing different ligands are described. When 5,6-dimethyl-1,10-phenanthroline was used as the ligand, exclusively α-difluoromethylated products were obtained, while γ-selective difluoromethylated products were generated when N-heterocyclic carbene-SIPr was used as the ligand. Likewise, high α- vs. γ-selectivities were achieved in the presence of similar copper catalysts for the reactions of propargyl bromides. Moreover, a copper-catalyzed asymmetric allylic difluoromethylation reaction with moderate to good enantioselectivity by the use of chiral ligands was developed.

关键词： fluorine difluoromethyl copper asymmetric allylic substitution

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Rh(Ⅰ)-catalyzed regio-and enantioselective allylic alkylation of Meldrum's acid

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Chinese Chemical Letters 2021年第1期32卷 385-388页

作者： Min Liu Haiying Zhao Changkun Li Inner Mongolia Key Laboratory of Fine Organic Syrthesis Cllge of Chemistry and Chemical Enginpering Inner Mongolia UniversityHohhor 010021China Shanghai Key Laboratory for Molcular Engineering of Chirnl Drugs School of Chemistry and Chermical Engineering Shanghai Jiao Tong UiversitShanghai 200240China

A Rh(Ⅰ)-catalyzed highly regio-and enantioselective allylic alkylation of Meldrum acid with racemic allylic substrates bearing alkyl groups has been developed.The applying of chiral bisoxazopinephosphine ligand is essential for the high yields and selectivities.This method provides a rapid access to various chiral β-alkyl-γ,δ-unsaturated carboxylic acids and their derivatives.

关键词： Rhodium Bisoxazolinephosphine allylic substitution Meldrum’s acid Asymmetric catalysis

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A Pd/Cu Bimetallic Catalysis for the Asymmetric Synthesis of α,α-Disubstituted α-Amino Acid Derivatives

A Pd/Cu Bimetallic Catalysis for the Asymmetric Synthesis of...

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中国化学会第十三届全国有机合成化学学术研讨会

作者： Huo Xiaohong He Rui Zhang Wanbin School of Pharmacy Shanghai Jiao Tong University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University

Synergistic catalysis is gaining increasing attention due to its many perceived advantages such as improved catalytic activity,wide substrate scope,increased selectivity,and cost efficiency.1 Recently,we have developed several methodologies involving the synergistic combination of metal catalysts and organocatalysts.2 And this strategy has been utilized in asymmetric transformations with some success by using a chiral catalyst in conjunction with a second achiral catalyst.In comparison,the development of bimetallic catalysis with two distinct chiral metal catalysts remains underdeveloped.Herein,we describe a cooperative bimetallic catalysis system consisting of a chiral palladium complex and a chiral copper complex for the highly enantioselective allylic alkylation of aldimine Schiff base,offering a reliable catalytic process for the asymmetric synthesis of α,α-disubstituted α-amino-acid derivatives.

关键词： inter-bimetallic allylic substitution dual catalysis

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