Kumari Saloni, Joshi Abhisek, Borthakur Ishani, Kundu Sabuj
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, Uttar Pradesh, India.
J Org Chem. 2023 Aug 18;88(16):11523-11533. doi: 10.1021/acs.joc.3c00674. Epub 2023 Jul 31.
The transformation of ethanol to value-added chemicals has tremendous potential. However, generally, harsh reaction conditions are needed for the functionalization of ethanol due to its high dehydrogenation energy. Herein, a metal-free photo-mediated activation of challenging ethanol and higher aliphatic alcohols for the synthesis of differently functionalized benzimidazoles under mild conditions is disclosed. The interplay of a photocatalyst and a HAT reagent facilitated the activation of aliphatic alcohols. A wide array of diamines with different functional groups were well tolerated, and the protocol was also extended to -substituted diamines for the synthesis of industrially important benzimidazoles. A probable catalytic cycle was proposed based on various mechanistic studies.
