Suzuki−Miyaura Cross-Coupling of Aryl Carbamates and Sulfamates: Experimental and Computational Studies
作者:Kyle W. Quasdorf、Aurora Antoft-Finch、Peng Liu、Amanda L. Silberstein、Anna Komaromi、Tom Blackburn、Stephen D. Ramgren、K. N. Houk、Victor Snieckus、Neil K. Garg
DOI:10.1021/ja200398c
日期:2011.4.27
The first Suzuki-Miyaura cross-coupling reactions of the synthetically versatile aryl O-carbamate and O-sulfamate groups are described. The transformations utilize the inexpensive, bench-stable catalyst NiCl2(PCy3)(2) to furnish biaryls in good to excellent yields. A broad scope for this methodology has been demonstrated. Substrates with electron-donating and electron-withdrawing groups are tolerated, in addition to those that possess ortho substituents. Furthermore, heteroaryl substrates may be employed as coupling partners. A computational study providing the full catalytic cycles for these cross-coupling reactions is described. The oxidative addition with carbamates or sulfamates occurs via a five-centered transition state, resulting in the exclusive cleavage of the aryl C-O bond. Water is found to stabilize the Ni-carbamate catalyst resting state, which thus provides rationalization of the relative decreased rate of coupling of carbamates. Several synthetic applications are presented to showcase the utility of the methodology in the synthesis of polysubstituted aromatic compounds of natural product and bioactive molecule interest.
US3985896A
申请人:——
公开号:US3985896A
公开(公告)日:1976-10-12
Benzophenalenofurans
申请人:SmithKline Corporation
公开号:US03985896A1
公开(公告)日:1976-10-12
The compounds are benzophenalenofurans having pharmacological activity, in particular, coronary vasodilator activity.