Bis(amino)cyclopropenium salt Catalyzed 1,6-Conjugate Addition of Thiols to p-Quinone Methides

Abstract

Bis(amino)cyclopropenium salt has been utilized as a H-bond donor catalyst for the 1,6- conjugate addition of thiols to para-quinone methides. Here the bis(amino)cyclopropenium salt acts as a Brønsted acid for the catalysis. The transformation occurs at mild conditions and is tolerant to a variety of functional groups. This protocol provides an easy and simple access to various unsymmetrical diarylmethyl thioether in good to excellent yield.