N-Heterocyclic carbene-catalyzed [4＋2] cyclization of a-chloroaldehydes and aurones： Highly enantioselective synthesis of benzofuran-fused dihydropyran-2-ones  

作　　者：Yao Li Kunquan Chen Yan Zhang Dequn Sun Song Ye 

机构地区：[1]Marine College, Shandong University at Weihai, Weihai 264209, China [2]Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China [3]University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Chemical Letters》2018年第8期1209-1211,共3页中国化学快报（英文版）

基　　金：The Financial support from the National Natural Science Foundation of China (Nos. 21425207, 21521002);the Chinese Academy of Sciences is greatly acknowledged

摘　　要：The chiral N-heterocyclic carbene-catalyzed [4 ＋ 2] annulation of a-chloroaldehydes and aurones was developed, giving the corresponding benzofuran–fused dihydropyranones in good to high yields with good diastereoselectivities and excellent enantioselectivities. The catalytic cycle features with the generation of enolate from chloroaldehdye and its following [4 ＋ 2] cycloaddtion with aurones.The chiral N-heterocyclic carbene-catalyzed [4 ＋ 2] annulation of a-chloroaldehydes and aurones was developed, giving the corresponding benzofuran–fused dihydropyranones in good to high yields with good diastereoselectivities and excellent enantioselectivities. The catalytic cycle features with the generation of enolate from chloroaldehdye and its following [4 ＋ 2] cycloaddtion with aurones.

关 键 词：Carbene catalysis ANNULATION ENANTIOSELECTIVITY BENZOFURAN Dihydropranone 

分 类 号：O626[理学—有机化学]