Nickel‐Catalyzed Enantioselective Synthesis of 2,3,4‐Trisubstituted 3‐Pyrrolines.

The development of synthetic methods to produce highly functionalized chiral 3‐pyrrolines is of indisputable importance because of their prevalence in natural and synthetic bioactive molecules. Unfortunately, previous general cycloaddition approaches using allenoates, could not synthesize 3,4‐disubstituted 3‐pyrrolines. Herein, an original approach to yield 2,3,4‐trisubstituted 3‐pyrrolines with chirality at the 2‐position is presented. A NiII/Fc‐i‐PrPHOX catalytic system facilitated a redox‐neutral highly stereoselective process that exhibited an enantioselectivity of up to 99 %. Enantioenriched 3‐pyrrolines can be converted to other valuable classes of N‐heterocycles. [ABSTRACT FROM AUTHOR]