Chiral Guanidinium Salt Catalyzed Enantioselective Phospha‐Mannich Reactions

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. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.