Gold-Catalyzed Oxidative Ring Expansions and Ring Cleavages of Alkynylcyclopropanes by Intermolecular Reactions Oxidized by Diphenylsulfoxide
作者:Chia-Wen Li、Kamalkishore Pati、Guan-You Lin、Shariar Md. Abu Sohel、Hsiao-Hua Hung、Rai-Shung Liu
DOI:10.1002/anie.201004647
日期:2010.12.17
A golden opportunity: A novel gold‐catalyzed oxidativering‐expansion of unactivated cyclopropylalkynes using Ph2SO has been developed (see scheme). For substrates bearing a donor group at the cyclopropane ring, preliminary results reveal a distinct cleavage of the cyclopropane unit; such a ringcleavage is further applicable to the synthesis of 2H‐pyrans. L=P(tBu)2(o‐biphenyl), Tf=triflate.
Divergent Construction of Fully Substituted Pyrroles and Cyclopentadiene Derivatives by Ynamide Annulations: 1,2-Cyclopropyl Migration versus Proton Transfer
作者:Wenqing Zang、Yin Wei、Min Shi
DOI:10.1021/acs.orglett.0c01819
日期:2020.7.17
cyclopropyl ynamide cyclization to construct fully substituted pyrroles and cyclopentadienederivatives in the presence of a gold catalyst was developed. In this version of pyrrole generation, a novel method to furnish gold vinylidenes through [1,2]-cyclopropyl migration was described. On the contrary, the production of cyclopentadienes proceeded through a proton-transfer step. These intriguing mechanisms