Ag-Catalyzed Remote Unactivated C(sp3)-H Heteroarylation of Free Alcohols in Water

Org Lett. 2021 Feb 5;23(3):722-726. doi: 10.1021/acs.orglett.0c03944. Epub 2021 Jan 13.

Abstract

Catalyzed by silver salt, the unactivated C(sp3)-H heteroarylation of free alcohol at the δ position is realized under gentle thermal conditions in water through a radical procedure. Both protonic acids and Lewis acids are found to be efficient for activating pyridines for this Minisci-type reaction. The reaction enjoys a good functional group tolerance and substrate scope. Terminal secondary and tertiary alcohols are suitable substrates. With either electron-donating or -withdrawing groups, the electron-deficient heteroarene substrates generate the target products in moderate to good yields. A gram-scale experiment can be successfully operated. A radical blocking experiment and a radical clock experiment are studied to support the radical mechanism.