<i>N</i>,<i>N-</i>Diethyl<i>O-</i>Carbamate: Directed Metalation Group and Orthogonal Suzuki−Miyaura Cross-Coupling Partner

Abstract

The first Suzuki-Miyaura cross-coupling of an aryl O-carbamate, a versatile and powerful directed metalation group (DMG) in directed ortho metalation (DoM) chemistry, is described using the inexpensive, bench-stable catalyst NiCl(2)(PCy(3))(2). Broad synthetic scope and good efficiency are demonstrated for aryl and heteroaryl O-carbamates. The role of water and hydrolysis equilibrium between free boronic acid and boroxine was established to be a crucial parameter for this transformation. When combined with DoM and traditional Pd-catalyzed Suzuki-Miyaura strategies, the methodology offers concise routes to uniquely substituted molecules, avoiding the need for protection/deprotection of the phenol and the use of strongly nucleophilic cross-coupling partners.