Department of Chemistry, University of Chicago, Chicago, IL, 60637, USA.
College of Chemical Engineering, Nanjing University of Science & Technology, Nanjing, 210094, P. R. China.
Angew Chem Int Ed Engl. 2018 Mar 1;57(10):2702-2706. doi: 10.1002/anie.201712487. Epub 2018 Feb 6.
The development of a catalytic intramolecular "cut-and-sew" transformation between cyclobutanones and alkynes to construct cyclohexenone-fused rings is described herein. The challenge arises from the need for selective coupling at the more sterically hindered proximal position, and can be addressed by using an electron-rich, but less bulky, phosphine ligand. The control experiment and C-labelling study suggest that the reaction may start with cleavage of the less hindered distal C-C bond of cyclobutanones, followed by decarbonylation and CO reinsertion to enable Rh insertion at the more hindered proximal position.
本文描述了一种在环丁酮和炔烃之间进行催化分子内“切和缝”转化的方法，以构建环己烯酮稠合环。挑战在于需要在空间位阻更大的近位选择性偶联，可以通过使用富电子但体积较小的膦配体来解决。对照实验和 C 标记研究表明，反应可能首先从环丁酮的非位阻较小的远端 C-C 键断裂开始，然后脱羰和 CO 重新插入，以在空间位阻更大的近位允许 Rh 插入。
