The first diastereo-and enantioselective cyclopropanation reactions of electron-deficient allenes with donor-acceptor and diacceptor diazo reagents are described. The desired enantioenriched alkylidenecyclopropanes (ACPs) were obtained in high yields with high diastereo-and enantioselectivities in the presence of Rh 2 ((S)-TCPTAD) 4 or Rh 2 ((R)-BTPCP) 4 catalysts (up to 95 % yield, > 95 : 5 d.r. and 99 : 1 e.r.). This methodology gave a direct access to ACPs bearing multiple electron-deficient substituents and allows to further expand the availability of ACPs chemistry. Interestingly, during the examination of the scope of this reaction, the asymmetric intramolecular CÀ H insertion reaction into tert-butyl group was observed as a side reaction with up to 94 : 6 e.r.

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