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Alkaloid-Catalyzed Enantioselective [3 + 2] Cycloaddition of Ketenes and Azomethine Imines.

ABSTRACT: A new asymmetric synthesis of bicyclic pyrazolidinones through an alkaloid-catalyzed formal [3 + 2] cycloaddition of in situ generated ketenes and azomethine imines is described. The products were formed in good to excellent yields (52-99% for 17 examples), with good to excellent diastereoselectivity (dr 5:1 to 27:1 for 11 examples), and with excellent enantioselectivity in all cases (?96% ee). This method represents the first unambiguous example of an enantioselective reaction between ketenes and a 1,3-dipole.

SUBMITTER: Mondal M

PROVIDER: S-EPMC5012990 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature

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Alkaloid-Catalyzed Enantioselective [3 + 2] Cycloaddition of Ketenes and Azomethine Imines.

Mondal Mukulesh M Wheeler Kraig A KA Kerrigan Nessan J NJ

Organic letters 20160808 16

A new asymmetric synthesis of bicyclic pyrazolidinones through an alkaloid-catalyzed formal [3 + 2] cycloaddition of in situ generated ketenes and azomethine imines is described. The products were formed in good to excellent yields (52-99% for 17 examples), with good to excellent diastereoselectivity (dr 5:1 to 27:1 for 11 examples), and with excellent enantioselectivity in all cases (≥96% ee). This method represents the first unambiguous example of an enantioselective reaction between ketenes a ...[more]

PMID: 27498770

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