A New Synthesis of Dihydropyridin-2-ones from Brassard’s Diene and Imines
摘要:
A new method for the synthesis of dihydropyridin-2-ones from various N-2-nitrobenzenesulfonyl (nosyl) imines and 1,3-diethoxy-1-trimethylsiloxy-1,3-butadiene (Brassard's diene) under weakly-basic conditions is described. This synthesis of dihydropyridin-2-ones involves the initial addition reaction of Brassard's diene to imines to afford the adducts followed by a cyclization reaction that forms the corresponding 4-ethoxy-5,6-dihydro-1H-pyridin-2-ones in moderate to good yields after deprotection of its nosyl group from the adducts.
Expanding the Utility of Brønsted Base Catalysis: Biomimetic Enantioselective Decarboxylative Reactions
作者:Yuanhang Pan、Choon Wee Kee、Zhiyong Jiang、Ting Ma、Yujun Zhao、Yuanyong Yang、Hansong Xue、Choon-Hong Tan
DOI:10.1002/chem.201100687
日期:2011.7.18
of simple esters, the use of them as nucleophiles in directasymmetric transformations is a long‐standing challenge in synthetic organic chemistry. Nature approaches this difficulty through a decarboxylative mechanism, which is used for polyketide synthesis. Inspired by nature, we report guanidine‐catalyzed biomimetic decarboxylative CC and CN bond‐formation reactions. These highly enantioselective