Organocatalytic asymmetric destruction of 1-benzylated Reissert compounds catalysed by quaternary cinchona alkaloids.

The enantiomeric enrichment of racemic 1-benzylated Reissert compounds under organocatalytic biphasic conditions is presented. The enrichment is the consequence of an asymmetric destruction of the racemic compounds resulting in the formation of the corresponding 1-benzylated isoquinolines. The highest selectivity has been achieved using quaternary cinchona alkaloids as phase-transfer catalysts. The resolution of a number of racemic 1-benzylated Reissert compounds reveals a significant substrate dependence and a proposal for the mechanism of the reaction is presented.