Investigation of the transition-metal- and acid-catalyzed reactions of β-(N-tosyl)amino diazo carbonyl compounds

A series of beta-(N-tosyl)amino diazo carbonyl compounds have been prepared by nucleophilic condensation of N-tosylimines with acyldiazomethanes. The diazo decomposition of these diazo carbonyl compounds under various catalytic conditions, including Rh(II) carboxylates, Cu(I) and Cu(II) complexes, PhCO2Ag/Et3N, TsOH, and SnCl2.2H(2)O, has been investigated. It was found that, in most cases, the diazo decomposition gave preferentially 1,2-aryl migration product, but 1,2-hydride migration predominated when PhCO2Ag/Et3N was the catalytic system. Hammett correlation has been applied in the analysis of the electronic effects of 1,2-aryl migration. The factors that govern the migratory preference and the mechanistic aspects of the reaction are discussed.