Photoinduced, Metal-Free Hydroacylation of Aromatic Alkynes for Synthesis of α,β-Unsaturated Ketones via C(sp<sup>3</sup>)–H Functionalization
Ambuj Kumar Kushwaha, Arsala Kamal, Himanshu Kumar Singh, Suresh Kumar Maury, Tusar Mondal, Sundaram Singh
Abstract
Despite the notable advancements made over the past decade in achieving carbon–carbon bonds by transition-metal-catalyzed cross-coupling processes, metal-free cross-coupling reactions for hydroacylation of aromatic alkynes via C(sp 3 )–H functionalization are still rare and highly desired. Here we report a metal-free reliable approach for the synthesis of α,β-unsaturated ketones (chalcones) via C(sp 3 )–H functionalization using MeCN:H 2 O as green solvent, Eosin Y as organic photocatalyst, and ambient air as oxidant. More significantly, this strategy can effectively transform a variety of methyl arenes and aromatic alkynes into the desired product. With high atom efficiency, use of green solvents, metal-free nature, environmental friendliness, and visible light as a renewable energy source, this method is compatible with biologically active molecules.