N-H insertion reactions of rhodium carbenoids .1. Preparation of alpha-amino acid and alpha-aminophosphonic acid derivatives

Rhodium(II) acetate-catalysed decomposition of diazophenylacetates 1 and 3 in the presence of a range of N-H compounds results in an N-H insertion reaction of the intermediate carbenoids and formation of N-substituted phenylglycine derivatives 2 and 4. The corresponding reactions of dimethyl alpha-diazobenzylphosphonate 5 constitute a simple route to aminophosphonates 6.