Generation and Chemical Properties of Dicyclopropylcarbene. Ring Expansion, Chlorine Abstraction, C-H Insertion, and Alkene Addition Reactions

Article abstract of DOI:10.1021/ja00355a026

Thermolysis of 5,5-dicyclopropyl-2-methoxy-2-methyl-Δ³-1,3,4-oxadiazoline in solution at 80 deg C affords dicycloproylcarbene and methyl acetate in high yields.Dicyclopropylcarbene undergoes a variety of reactions including ring expansion to 1-cyclopropylcyclobutene, chlorine atom abstraction from carbon tetrachloride, and efficient insertion into the CH bond of chloroform.A rationale for the very different reactions of the carbene with CCl4 and CHCl3 is suggested.Carbene trapping by addition to tetrachloroethylene, using the oxadiazoline as the carbene source, is illustrated with the preparation of an adduct.