Developing a sustainable catalytic method for reducing aryl carboxylates to methyl arenes is desirable and challenging. A well-defined cobalt-catalyzed reduction of carboxylate esters to methyl and allyl arene is developed. This catalytic transformation employs a sub-stoichiometric amount of base, and diethylsilane as a reductant. Diverse alkyl, aryl carboxylate, and cinnamate esters are amenable to this catalytic transformation. Mechanistic investigations revealed the involvement of silyl acetal and silyl ether intermediates and a radical pathway. Catalytic activation of the Si-H bond of silanes, C-O bond of ester and silyl ether intermediates by cobalt is crucial to the success of this exhaustive reduction reaction. Catalytically active Co(I) and Co (III) intermediates are established by mass spectral analyses and a relevant catalytic cycle operating via amine-amide metal-ligand cooperation is proposed.

Manas Kumar Sahu has completed his M.Sc. from Sambalpur University, India and currently pursuing Ph.D. at School of Chemical Sciences, National Institute of Science Education and Research (NISER). His research focuses on organic synthesis and the development of organometallic catalysis.