Diphenylphosphinoyl protection

A new general synthesis of primary and secondary amines utilizes phase-transfer-catalysed alkylation of diphenylphosphinic amide, which is readily available (Scheme 3), The alkylation step is limited to primary alkyl halides as alkylating agents, but the diphenylphosphinoyl protecting group is superior to the diethoxyphosphonyl group reported previously/... 

The chiral acetals (10) are attacked by triethyl phosphite at low temperatures in the presence of titanium(IY) chloride to give 1-alkoxyphosphonates (1 la,b) with a high degree of diastereoselecti-vity the main diastereomers (11a) were purified and used to prepare pure (S)-enantiomers of a-aminophosphonic acids. Phosphono-, phenylphosphinico-, and diphenylphosphinoyl-sarcosine (12) have been prepared in improved yields by Arbuzov reactions on the protected sarcosine derivative (13).7... 

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