文献类型：期刊文献

英文题名：Zwitterionic π-Allyl-Pd Species Enabled [2σ+2π] Cycloaddition Reactions of Vinylbicyclo[1.1.0]butanes (VBCBs) with Alkenes, Carbonyls, and Imines

作者：Li, Tianxiang[1,2];Wang, Yao[1,2];Xu, Yang[1,2];Ren, Haosong[1,2];Lin, Zhongren[1,2];Li, Zhenyue[1,2];Zheng, Jun[1,2]

机构：[1]Minist Educ, Engn Res Ctr Pharmaceut Proc Chem, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Pharm, Shanghai 200237, Peoples R China

年份：2024

卷号：14

期号：24

起止页码：18799

外文期刊名：ACS CATALYSIS

收录：;EI(收录号：20245017524607);WOS:【SCI-EXPANDED(收录号:WOS:001374978100001)】；

基金：This work was supported by National Natural Science Foundation of China (22301075), Shanghai Scientific and Technological Innovation Projects (23ZR1417400), East China University of Science and Technology for startup funding, the Program of Introducing Talents of Discipline to Universities and the 111 Project (BP0719034)

语种：英文

外文关键词：palladium; asymmetric catalysis; cycloadditionreaction; bridged bicyclic scaffolds; vinyl bicyclo[1.1.0]butanes

摘要：Transition-metal-catalyzed cycloaddition reactions of strained small-ring compounds are powerful methods for constructing carbo- and heterocyclic structures of medicinal interest. However, the application of this strategy to bicyclo[1.1.0]butanes (BCBs), which are among the most strained carbocycles known, remains underdeveloped. Herein, we report vinylbicyclo[1.1.0]butane (VBCB) as a platform synthon for palladium-catalyzed formal [2 sigma+2 pi] cycloaddition reactions with various 2 pi-components, enabling the synthesis of BCHs, oxa-BCHs, and aza-BCHs under identical reaction conditions. The zwitterionic pi-allyl-Pd species generated through the palladium-catalyzed activation of VBCBs is the key to circumventing potential carbene reactivity and serves as a common intermediate for cycloadditions with diverse 2 pi-systems, including alkenes, aldehydes, ketones, and imines. Notably, by utilizing Pd2(dba)3 and an anthracene-derived Trost ligand, a wide array of BCHs bearing two vicinal chiral centers has been prepared in a highly diastereo-, and enantioselective manner. The generality and practicality of this method have been demonstrated by a broad substrate scope, scale-up reactions, and the versatile transformation of multiple functional groups into BCH scaffolds. Preliminary mechanistic studies support the formation of the pi-allyl-Pd species.