Chen Nuan, Zhou Ting, Zhang Hong, Zhu Yuqi, Lang Ming, Wang Jian, Peng Shiyong
School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, People's Republic of China.
School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry & Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, People's Republic of China.
J Org Chem. 2021 Mar 19;86(6):4714-4732. doi: 10.1021/acs.joc.1c00104. Epub 2021 Mar 5.
An unprecedented copper-catalyzed tandem reaction of 1,6-enynes with diazo compounds via a cross-coupling/[2 + 2] cycloaddition sequence was reported. A library of methylenecyclobutane-fused ring systems including cyclobuta[]indolines, cyclobuta[]benzofuran, benzo[]cyclobuta[]thiophene, and bicyclo[3.2.0] structures were obtained in moderate to excellent yields under very mild reaction conditions. The reaction exhibited high proximal-regioselectivity and diastereoselectivity. Moreover, 1,6-allenene has proven to be the key intermediate and proceeds via a thermally promoted [2 + 2] cycloaddition in the absence of copper catalyst.
报道了一种前所未有的铜催化的1,6-烯炔与重氮化合物通过交叉偶联/[2 + 2]环加成序列的串联反应。在非常温和的反应条件下，以中等至优异的产率获得了一系列包括环丁烷并[ ]吲哚啉、环丁烷并[ ]苯并呋喃、苯并[ ]环丁烷并[ ]噻吩和双环[3.2.0]结构的亚甲基环丁烷稠环体系。该反应表现出高的近端区域选择性和非对映选择性。此外，已证明1,6-丙二烯是关键中间体，并且在没有铜催化剂的情况下通过热促进的[2 + 2]环加成进行反应。
