Enantioselective tandem formation and [2,3]-sigmatropic rearrangement of cyclic propargylic oxonium ylides catalyzed by dirhodium(II) tetrakis[N-phthaloyl-(S)-tert-leucinate]
This paper describes the first examples of catalyst-dependent asymmetric induction in the periselective [2,3]-sigmatropic rearrangement of propargylic oxonium ylides generated by catalytic diazo decomposition. Catalysis of α-diazo-β-keto esters 4a-g using