Continuous Flow Esterification of a -Phosphinic Acid, and Transesterification of -phosphinates and -Phosphonates under Microwave Conditions.

The microwave (MW)-assisted direct esterification of phenyl--phosphinic acid, transesterification of the alkyl phenyl--phosphinates so obtained, and the similar reaction of dibenzyl phosphite (DBP) were investigated in detail, and the batch accomplishments were translated into a continuous flow operation that, after optimization of the parameters, such as temperature and flow rate, proved to be more productive. Alcoholysis of DBP is a two-step process involving an intermediate phosphite with two different alkoxy groups. The latter species are of synthetic interest, as precursors for optically active reagents.