Asymmetric Multicomponent Propargylations via Carbon Dioxide Shuttling and Fixation
Zi‐Han Li, Jiang-Shan Ma, Han-Yu Lu, Guo‐Qiang Lin, Zhi‐Tao He
Abstract
Catalytic asymmetric propargylic substitution reactions have received phenomenal progress and applications, but no study focuses on CO 2 gas capture and fixation in this area. The released CO 2 gas from the carbonate leaving group is usually taken as a waste. Herein, we describe a feasible strategy for unexplored asymmetric propargylation and alkynylallylic substitutions with CO 2 shuttling and CO 2 fixation. In addition, the Cu-catalyzed asymmetric multicomponent propargylation is also established, through which 13 C-labeled CO 2 is easily anchored into enantioenriched skeletons. With these two protocols, a series of valuable oxazolidinones, amino alcohols, and azetidine are prepared in high yields and enantioselectivities and applied to the concise asymmetric synthesis of natural product (−)-Cytoxazone. Extensive mechanistic experiments suggest the favorable role of DABCO in CO 2 capture and the carboxylative cyclization as a potential rate-limiting process.