Enantioselective α-Arylation of Aldehydes via Organo-SOMO Catalysis. An Ortho-Selective Arylation Reaction Based on an Open-Shell Pathway

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• 作者：Jay C. Conrad ; Jongrock Kong ; Brian N. Laforteza ; David W. C. MacMillan
• 刊名：Journal of the American Chemical Society
• 出版年：2009
• 出版时间：August 26, 2009
• 年：2009
• 卷：131
• 期：33
• 页码：11640-11641
• 全文大小：218K
• 年卷期：v.131,no.33(August 26, 2009)
• ISSN：1520-5126

文摘

The intramolecular α-arylation of aldehydes has been accomplished using singly occupied molecular orbital (SOMO) catalysis. Selective oxidation of chiral enamines (formed by the condensation of an aldehyde and a secondary amine catalyst) leads to the formation of a 3π-electron radical species. These chiral SOMO-activated radical cations undergo enantioselective reaction with an array of pendent electron-rich aromatics and heterocycles thus efficiently providing cyclic α-aryl aldehyde products (10 examples: ≥70% yield and ≥90% ee). In accordance with our radical mechanism, when there is a choice between arylation at the ortho or para position of anisole substrates, we find that arylation proceeds selectively at the ortho position.