Yan P, Zhong C, Zhang J, Liu Y, Fang H, Lu P. 3-(Methoxycarbonyl)Cyclobutenone as a Reactive Dienophile in Enantioselective Diels-Alder Reactions Catalyzed by Chiral Oxazaborolidinium Ions.
Angew Chem Int Ed Engl 2021;
60:4609-4613. [PMID:
33201584 DOI:
10.1002/anie.202014308]
[Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/16/2020] [Indexed: 11/06/2022]
Abstract
Cyclobutenone has been used as a highly reactive dienophile in Diels-Alder reactions, however, no enantioselective example has been reported. We disclose herein a chiral oxazaborolidine-aluminum bromide catalyzed enantioselective Diels-Alder reaction of 3-alkoxycarbonyl cyclobutenone with a variety of dienes. Furthermore, a total synthesis of (-)-kingianin F was completed for the first time via enantioenriched cycloadduct bicyclo[4.2.0]octane derivative.
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