Xiao Fu, Wei‐Tian Loh, Yan Zhang, Tao Chen Dr., Ting Ma, Hongjun Liu, Jianmin Wang and Choon‐Hong Tan Prof.
Angewandte Chemie International Edition, 2009, 40, 7387–7390. (Highlighted by Synfacts 2009, 11, 1281-1281; contributors: Benjamin List, Lars Ratjen)
Abstract: Zero, one, or two? Guanidinium catalyst 1⋅HBArF4 (ArF=3,5‐(CF3)2C6H3, Bn=benzyl, Ts=4‐toluenesulfonyl) was obtained in a single step from a commercially available diamine. By using this catalyst an asymmetric phospha‐Mannich reaction has been developed, involving secondary phosphine oxides and H‐phosphinates as the P nucleophile. A series of enantiomerically enriched α‐amino phosphine oxides (2), α‐amino phosphinate, and H‐phosphinates containing a P‐chiral center were prepared.
Paper download: https://doi.org/10.1002/anie.200903971