Dynamic Kinetic Resolution Processes Based on the Switchable Configurational Instability of Allenyl Copper Reagents.

The configurational instability of allenyl copper reagents is unveiled. An experimental study highlights the crucial role of Li and of the reaction temperature in the control of the configurational stability of allenyl copper reagents. A judicious choice of the reaction conditions allows efficient dynamic kinetic resolution processes and gives a one-pot access to homopropargylic alcohols or amines bearing up to four contiguous defined stereogenic centers.