Copper Photoredox Catalyzed A3’ Coupling of Arylamines, Terminal Alkynes, and Alcohols through a Hydrogen Atom Transfer Process

Abstract

The first successful example of the three-component coupling of N-alkylanilines,terminal alkynes,and alcohols was achieved at room temperature by av isible-light-mediated copper-catalyzed photoredox hydrogen-atom transfer process. This method allows preparation of propargylamines through uniquely selective a-C À Hb ond activation of unactivated alkylalcohols.P reliminary studies indicate that formation of a-oxy radical is operative.T his approach facilitates rapid access to biologically important propargylamines from methanol as an abundant feedstock. Scheme 1. Transition metal catalyzed activation of methanol.

Visible‐Light‐Induced Photocatalyst‐Free Oxidative Cyclization of Primary Alcohols by Selectfluor via HAT Process: Synthesis of Quinazolinones and Benzothiadiazines

“…[15][16][17][18] Past few years, visible light mediated metal and metal-free photoredox catalysts have been employed for α C(sp 3 )À H functionalization of alcohols. [19][20][21][22][23][24] For examples, in 2019, Xu et al [25] has reported visible light mediated one pot synthesis of quinazolinones by selective oxidation of alcohols via hydrogen atom transfer (HAT) using organic dye as photosensitizer. Recently, Sarma et al [26] developed visible light mediated synthesis of quinazolinones and quinoxalines in the presence of TBHP as an oxidizing agent in aqueous medium without photoredox catalysts.…”