A Highly Efficient Asymmetric Synthesis of Quaternary Stereocenter-Containing Indolizidine and Quinolizidine Alkaloids Using Aldehydes, Nitroalkenes, and Unactivated Cyclic Ketimines.

A highly efficient approach for the construction of indolizidines and quinolizidines bearing a bridged quaternary stereocenter has been established in a one-pot fashion using aldehydes, nitroalkenes, and cyclic ketimines with excellent enantioselectivities and in high yields. Moreover, this method could be applied to the synthesis of indolizidines in the gram scale.