Selective catalysed decompositions of one diazo group in the presence
of another are discussed. A range of bis(diazo) compounds was prepared
in which the two diazo groups are differentially substituted. Rhodium
(II) acetate catalysed decomposition in the presence of methanol resul
ted in exclusive O-H insertion reaction at the more reactive diazo gro
up, the less reactive diazophosphonate remaining intact. With the more
active rhodium(II) trifluoroacetamide as catalyst, both diazo groups
decomposed simultaneously. (C) 1998 Elsevier Science Ltd. All rights r
eserved.