Practical Synthesis of Enantiomerically Pure 2-(Diphenylphosphanyl)ferro­cene Carboxylic Acid

Abstract

A practical synthesis of both enantiomers of ortho-diphenylphosphanylferrocene carboxylic acid (o-DPPFA) starting from ferrocene is described. Key steps include the synthesis of the racemic title compound from ferrocene in two steps followed by resolution by way of diastereomeric ester formation with glucose diacetonide. The synthesis allows for preparation of gram quantities of both optical antipodes of o-DPPFA (3) in good yields and enantiomerically pure form (>99% ee).