Gold-catalyzed ketene dual functionalization and mechanistic insights:divergent synthesis of indenes and benzo[d]oxepines  

作　　者：Ming Bao Jinzhou Chen Chao Pei Sujie Zhang Jinping Lei Wenhao Hu Xinfang Xu 

机构地区：[1]Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery,School of Pharmaceutical Sciences,Sun Yat-sen University,Guangzhou 510006,China

出　　处：《Science China Chemistry》2021年第5期778-787,共10页中国科学（化学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(21971262,92056201);the National Postdoctoral Program for Innovative Talents(BX20190399);Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery(2019B030301005);the National Mega-project for Innovative Drugs(2019ZX09721001-006-001);the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2016ZT06Y337);the Fundamental Research Funds for the Central Universities(20ykpy113,18843407).

摘　　要：An unprecedented gold-catalyzed ketene C=O/C=C bifunctionalization method has been developed.Mechanistic studies and density function theory(DFT)calculations indicate that the reaction is initiated by gold-catalyzed Wolff rearrangement of diazoketone to form the ketene intermediate,followed by intermolecular nucleophilic addition and terminated with two divergent cyclization processes via enol intermediates.In the case with alcohols as the nucleophiles,the reaction goes through a C-5-endodig carbocyclization to give the indene products;whereas,O-7-endo-dig cyclization occurs dominantly when indoles/pyrroles are used as the nucleophiles,delivering the 7-membered benzo[d]oxepines.In comparison with the well-documented cycloaddition and nucleophilic addition reactions,this cascade reaction features a novel reaction pattern for the ketene dual functionalization through addition with nucleophile and electrophile in sequence.

关 键 词：metal carbene ketene dual functionalization Wolff rearrangement gold catalysis INDENE benzo[d]oxepine 

分 类 号：O621.251[理学—有机化学]