Organic Letters 2014-10-03

O-Monoacyltartaric acid catalyzed enantioselective conjugate addition of a boronic acid to dienones: application to the synthesis of optically active cyclopentenones.

Masaharu Sugiura, Ryo Kinoshita, Makoto Nakajima

Index: Org. Lett. 16(19) , 5172-5, (2014)

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Abstract

Enantioselective conjugate addition of styrylboronic acid to dienones was effectively catalyzed by an O-monoacyltartaric acid to afford monostyrylated products with good enantioselectivity. The RCM of the monostyrylated products using the Hoveyda-Grubbs II catalyst afforded optically active cyclopentenones, including a synthetic intermediate of the antitumor agent TEI-9826. The study shows that a diene additive such as 1,6-heptadiene or diallyl ether was essential for the RCM.