Cobalt-Catalyzed Chemoselective Transfer Hydrogenative Cyclization Cascade of Enone-Tethered Aldehydes
作者:Shuang-Shuang Ma、Biao-Ling Jiang、Zheng-Kun Yu、Suo-Jiang Zhang、Bao-Hua Xu
DOI:10.1021/acs.orglett.1c00992
日期:2021.5.21
The ligand-free Co-catalyzed chemoselective reductive cyclization cascade of enone-tethered aldehydes with i-PrOH as the environmentally benign hydrogen surrogate is developed by this study. Mechanistic studies disclosed that such a protocol is initiated by an ortho-enone-assisted Co(I)-catalyzed reduction of the aldehyde functionality with i-PrOH. Meanwhile, the selectivity from the Michael–Aldol
本研究开发了以i -PrOH为环境良性氢替代物的烯键式醛的无配体共催化化学选择性还原环化级联反应。机制研究揭示,这种协议是由发起邻-enone辅助的Co(I)催化还原的醛官能团与我的i-PrOH。同时,从Michael–Aldol环还原级联到oxa-Michael级联的选择性是可行的,并且可以通过添加空间Lewis碱(例如TEMPO和DABCO)轻松地进行调节,分别提供取代的1 H-茚和二氢异苯并呋喃。