Gold(I)-Catalyzed Intermolecular Cycloaddition ofAllenamides with α,β-Unsaturated Hydrazones: EfficientAccess to Highly Substituted Cyclobutanes.

α,β-Unsaturated N,N-dialkyl hydrazones undergo a mild [2+ 2] cycloaddition to allenamideswhen treated with a suitable gold catalyst. The method, which representsthe first application of N,N-dialkylhydrazones in gold catalysis, is compatible with a wide variety ofsubstituents at the alkenyl moiety of the hydrazone component, proceedswith excellent levels of regio- and diastereoselectivity, and providesdensely substituted cyclobutanes with good to excellent yields. [ABSTRACT FROM AUTHOR]