Département de chimie moléculaire

α‐Diazo β‐hydroxyamino esters, readily obtained by the addition of lithiated ethyl diazoacetate to cyclic nitrones, react smoothly in the presence of metal catalysts to produce ketonitrones. This transformation results from a selective 1,2‐hydride shift of the metal carbenoid intermediates. The process is particularly efficient for diazo‐N‐hydroxypyrrolidine systems. For diazo‐N‐hydroxypiperidine substrates, C–H insertion can be a competitive reaction.