Organocatalytic asymmetric[2+2] cycloaddition of alkynes with quinones  

作　　者：Huai-Ri Sun Lan Yang Yu Li Le Yu Bo-Bo Gou Atif Sharif Qing-Song Jian Jie Chen Ling Zhou 

机构地区：[1]Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education,College of Chemistry&Materials Science,Northwest University,Xi’an,710127,China

出　　处：《Science China Chemistry》2023年第8期2292-2299,共8页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC 21672170);the Natural Science Basic Research Plan in Shaanxi Province of China(2021JZ-40);Shaanxi Fundamental Science Research Project for Chemistry&Biology(22JHQ007)。

摘　　要：A chiral phosphoric acid catalyzed enantioselective[2+2] cycloaddition of alkynylindols or alkynylnaphthols with quinones is disclosed.A class of functionalized cyclobutenes with excellent yields,diastereo-and enantioselectivities were prepared under mild reaction conditions(70 examples,up to 99%yield,99%ee,all>50:1 dr).Mechanistic studies revealed that a dearomatization of indole or naphthol occurred to initiate the cycloaddition,followed by an intramolecular Michael addition with in situ generated allene-iminium or vinylidene-quinone methide intermediate.The competitive[2+3] cycloaddition was prevented in this catalytic system.An interesting central to axial chirality conversion via a rearrangement process was realized during transformation of the product.

关 键 词：ORGANOCATALYSIS [2+2]cycloaddition asymmetric catalysis ALKYNES CYCLOBUTENES 

分 类 号：O621.251[理学—有机化学]