CuI in biorenewable basic medium: Three novel and low E-factor Suzuki-Miyaura cross-coupling reactions

Abstract

• First use of waste-derived material for Cu-Catalyzed Suzuki-Miyaura coupling. • Utilization of biorenewable waste derived materials. • Actual application of waste to industrially relevant transformation. • Very low E-factor and improved TON and TOF values. • Sustainable synthesis of biaryls using challenging Cu-Catalyst. • Large scope for future investigations. • Ease of handling and wide substrate scope. In this article, we have disclosed three inexpensive and novel copper-catalyzed C(sp 2 )–C(sp 2 ) coupling reactions of substituted aryl/heteroaryl halides with arylboronic acids by employing water extract of pomegranate ash (WEPA) as biorenewable base and aqueous reaction medium. CuI/WEPA, CuI/WEPA/DABCO, CuI/WEPA/SPhos catalytic systems were developed for the present Suzuki-Miyaura coupling. WEPA has been found to be the effective base and reaction medium for copper-catalysed Suzuki-Miyaura reactions with and without ligands to provide good to high yields of coupling products. This method has remarkable advantages like inexpensive and waste-derived biorenewable base, low catalyst loading, moderate temperature, replacement of precious palladium with abundant copper, no or negligible contamination of copper in products, low E-factor, high chemoselectivity and a large substrate scope.