N–H insertion reactions of rhodium carbenoids. Part 1. Preparation of α-amino acid and α-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 α-diazobenzylphosphonate 5 constitute a simple route to aminophosphonates 6.