A diastereo- and enantioselective synthesis of diazobicyclic oxadiazines was developed through an organocatalytic cycloaddition reaction. Asymmetric catalytic [3+3]-cycloaddition of γ-hydroxy-α,β-unsaturated carbonyls with N,N′-cyclic azomethine imines, using a squaramide-based catalyst, provided biologically important enantioenriched diazobicyclic oxadiazines in good yields with moderate to high diastereo- and enantioselectivities (up to 10:1 dr and 79:21 er).

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A novel approach of [3+3]‐cycloaddition of N,N′‐cyclic azomethine imines with γ‐hydroxy‐α,β‐unsaturated carbonyls was developed. Bicyclic oxadiazines were readily obtained in moderate to good yields from the reactions of various γ‐hydroxy‐α,β‐unsaturated ketones, including aromatic and aliphatic ketones, with N,N′‐cyclic azomethine imines under mild conditions, demonstrating the broad substrate scope.

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