Enantioselective copper-catalyzed cyclization of γ-alkenylsulfonamides and a δ-alkenylsulfonamide in the presence of a range of vinyl arenes results in variously functionalized 2-substituted chiral nitrogen heterocycles via a formal alkene C-H functionalization process. Application of this reaction to the concise synthesis of a 5-HT(7) receptor antagonist is demonstrated.
Enantio- and diastereoselective addition of thioacetic acid to nitroalkenes via N-sulfinyl urea catalysis
作者:Kyle L. Kimmel、MaryAnn T. Robak、Stephen Thomas、Melissa Lee、Jonathan A. Ellman
DOI:10.1016/j.tet.2012.01.048
日期:2012.3
The enantioselective addition of thioacetic acid to nitroalkenes was achieved using N-sulfinyl urea catalysis. In this report, the scope of the reaction was extended to the enantio- and diastereoselective thioacetic acid addition to cyclic alpha,beta-disubstituted nitroalkenes. Additionally, the role of the sulfinyl group was investigated by replacing it with a variety of aryl and sulfonyl groups. Of 15 urea catalysts synthesized and tested, none displayed comparable selectivity to the sulfinyl catalysts, highlighting the importance of the sulfinyl group in attaining high enantioselectivity in the thioacetic acid addition. (C) 2012 Elsevier Ltd. All rights reserved.