Scheme 1. Synthesis of bicyclo[3.1.0]hexanes. (A) Synthetic strategies towards bicyclo[3.1.0]hexanes. (B) (3 + 2) cycloaddition to access hetero bicyclo[3.1.0]hexanes from cyclopropenes. (C) Reported syntheses of bicyclo[3.1.0]hexanes from cyclopropenes. (D) This work: (3 + 2) annulation of aminocyclopropanes and cyclopropenes).
