A Gentle Method for the Preparation of a Variety of Ylides (As, Sb, Bi, S, Te, Thiouronium) from Diazo Compounds

Abstract
Bis(hexafluoroacetylacetonato)copper(II) is a very effective catalyst for the preparation of ylides from diazo compounds under mild conditions even down to room temperature. It appears that the lower the temperature at which the reaction can be conducted the purer the product which results. Its use in preparing arsonium, stibonium, bismuthonium, sulphonium, telluronium, and thiouronium ylides is described.