Copper Catalyzed Direct C-H Double Methylation of Aromatic Aldehydes Employing Methanol as an Alkylating Agent

Abstract

A mild sustainable protocol for the direct C-H double methylation of aromatic aldehydes has been accomplished by using un-activated methanol as a C1 source. Readily available, inexpensive copper sulfate has been utilized as a greener catalyst at room temperature. This methodology represents the first example of direct synthesis of tertiary alcohols from aromatic aldehydes operating via a concerted radical mediated pathway with the elimination of H2O2. The successful gram-scale synthesis of the product indicates the feasibility of this protocol in industrial applications.