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Copper-catalyzed condensation of imines and ?-diazo-?-dicarbonyl compounds: modular and regiocontrolled synthesis of multisubstituted pyrroles.

ABSTRACT: In the presence of a copper(ii) catalyst, enolizable imines bearing various N-substituents and ?-diazo-?-ketoesters undergo denitrogenative and dehydrative condensation to afford highly substituted pyrroles in moderate to good yields with exclusive regioselectivity. The reaction likely involves nucleophilic addition of the imine nitrogen to a copper carbenoid, tautomerization of the resulting azomethine ylide to an ?-enaminoketone, and a subsequent enamine-ketone cyclocondensation. With Yb(OTf)₃ as a unique cocatalyst, ?-diazo-?-diketones also participate in the same condensation reaction. The present reaction is applicable to acyclic, exocyclic, and endocyclic imines with tolerance of a broad range of functional groups and heterocyclic moieties, thus opening a new convenient route for the synthesis of the lamellarin family of natural products.

SUBMITTER: Tan WW

PROVIDER: S-EPMC6054072 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature

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