Transition Metal‐Free Vinylcyclopropanation of Olefins via Carbolithiation Reactions: Synthesis of 3‐Azabicyclo[3.1.0]hexanes

A formal vinylcyclopropanation of olefins from N ‐allyl N ‐(3‐alkoxymethyl‐2‐lithioallyl) amines acting as carbenoid equivalents is described. The reaction proceeds through a tandem 5‐ exo carbolithiation/3‐ exo S _N ʹ affording 1‐vinylazabicyclo[3.1.0]hexanes. Different substituents can be located at any of the other positions of the azabicycle, leading in most cases to high diastereoselectivities. DFT studies have been performed to account for the observed stereoselectivities that could not be rationalized in all cases through the expected chair‐like transition states.