Synthesis of Hydroxyl Functionalized Aryl/Alkyl Ketones via Visible-Light-Driven Cross-coupling of Benzoquinones and Alcohols at Room Temperature

Abstract

We developed a low-energy visible-light-mediated synthesis of 2,5-dihydroxyaryl /alkyl ketones and 2,5-dihydroxybenzaldehyde using inexpensive and readily available starting materials, benzoquinone and alcohols, at room temperature. Herein, triplet excited state benzoquinone and singlet oxygen (1O2) play an essential role in the hydroacylation of benzoquinone. The current photochemical method is simple, green, economically feasible, and works for both aromatic and aliphatic alcohols. Moreover, acyl hydroquinones are important precursors for the synthesis of various pharmaceutical drugs, including Cynandione A and anti-cancer drugs. Whereas, 2,5-dihydroxybenzaldehyde is an essential precursor for the synthesis of Gentisic acid.