A practical and efficient method for the resolution of 3‐phospholene 1‐oxides via coordination complex formation 1

A simple, efficient, and economical method based on the combination of the exceptional behavior of o , o′ ‐dibenzoyl‐ or o , o′ ‐di‐ p ‐toluyl‐( 2R , 3R )‐tartaric acid in chiral recognition processes, and the coordination ability of calcium or magnesium ion was developed for the resolution of phospholene oxides 1 . The calcium or magnesium salt of (−)‐ o , o′ ‐dibenzoyl‐( 2R , 3R )‐tartaric acid 2 , 4 ‐ 6 or calcium hydrogen (−)‐ o , o′ ‐di‐ p ‐toluyl‐( 2R , 3R )‐tartrate 3 may form crystalline diastereomeric coordination complexes with the appropriate antipode of substituted 3‐phospholene oxides 1 that makes possible efficient resolutions. Optically active phospholene oxides 1 were prepared directly by simply crystallization and digestion of the corresponding diastereomeric complexes so formed. Thermal behavior of the crystalline diastereomeric complexes was studied by simultaneous TG/DTA. The novel method may be of more general value in respect of the resolution of tertiary phosphine oxides. Chirality, 2010. © 2010 Wiley‐Liss, Inc.