Pd-Catalyzed asymmetric [5 + 2] cycloaddition of vinylethylene carbonates and cyclic imines: access to N-fused 1,3-oxazepines?

Organic & Biomolecular Chemistry Pub Date: 2020-11-23 DOI: 10.1039/D0OB02159H

Abstract

A Pd-catalyzed asymmetric [5 + 2] cycloaddition reaction was developed for the synthesis of N-fused 1,3-oxazepines using vinylethylene carbonates and sulfamate-derived cyclic imines. Under mild reaction conditions, a series of optically active N-fused 1,3-oxazepines were synthesized in good yields (up to 89%) and enantioselectivities (up to 90?:?10 er), indicating this method as a straightforward approach to enantiomerically enriched 1,3-oxazepine derivatives. The synthetic utility of the presented reaction was further demonstrated by the successful transformation of the resulting 1,3-oxazepines to useful polycyclic N-fused 1,3-oxazepanes.

Graphical abstract: Pd-Catalyzed asymmetric [5 + 2] cycloaddition of vinylethylene carbonates and cyclic imines: access to N-fused 1,3-oxazepines
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