Synthesis of α-nitro-α-diazocarbonyl derivatives and their applications in the cyclopropanation of alkenes and in O-H insertion reactions

A facile and highly efficient method for the preparation of alpha-nitro-alpha-diazocarbonyl derivatives by a diazo-transfer reaction involving (trifluoromethyl)sulfonyl azide has been developed. These substrates undergo a rhodium-catalyzed cyclopropanation reaction with a variety of alkenes. A systematic study of the reaction indicated that the diastereoselectivity of the cyclopropanation could be effectively controlled through the modification of the steric hulk of the diazo reagent. A novel O - H insertion reaction of the metal - carbene complex derived from the alpha-nitro-alpha-diazocarbonyl reagent afforded the corresponding, novel alpha-nitro-alpha-alkoxy carbonyl derivatives.