Aminoalkylphosphinic acids synthesis

Chen, S. and Coward, J.K., A general method for the synthesis of N-protected a-aminoalkylphosphinic acids, Tetrahedron Lett., 37, 4335, 1996. 

The first enantioselective synthesis of 1-aminoalkylphosphinic acids (319) based on the addition of phenylphosphinate (320) to chiral imines (321) and standard removal of protecting groups from the adducts (322) has been realized (Scheme 86). 

The ready oxidation of (l-aminoalkyl)phosphonous acids (aminoalkylphosphinic acids) with aqueous bromine, to give (l-aminoalkyl)phosphonic acids, raises still further the potential usefulness of the former. In a useful modification to one synthesis, the reaction between an aldehyde and either (R)- or (5 )-l-phenylethylamine hypophosphite salt yields the A-substituted (l-aminoalkyl)phosphinic acid which is simultaneously oxidized and deprotected when treated with bromine water. ... 

Scheme 13 Synthesis of a-Aminoalkylphosphinates from Phosphinic Acid 56"59 ...

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