Catalyst-free reductive hydrogenation or deuteration of aryl–heteroatom bonds induced by light

Abstract

The photoinduced hydrogenation or deuteration of quaternary arylammonium salts, aryl triflates, and aryl halides under catalyst-free conditions was achieved.

Radical deuteration

“…In 2021, Yao and co-workers 37 described a catalyst-free photochemical strategy for defunctionalization–deuteration under very simple reaction conditions. A broad range of aryl trimethylammonium salts ( 123 ), aryl triflates ( 125 ) and haloarenes ( 127 ) were smoothly deuterated with CD 3 OD or d 6 -DMSO as a deuterium source (Scheme 31).…”

Ammonium Salts as Convenient Radical Precursors Using Iridium Photoredox Catalysis

“…In recent years, an increased interest for such activation of ammonium salts led to the development of some radical processes for their reduction and/or functionalization. For instance, electrochemistry has been exploited to promote the carboxylation, borylation, and cyanation/cyanomethylation of benzylic and aryl ammonium salts, and UV-light irradiation has been used to promote the borylation and hydro-/deuterodeamination of aryl ammonium salts. Photoredox catalysis has been exploited to promote the carboxylation, reduction, borylation, and phosphonation of benzylic and aryl ammonium salts (Figure A).…”

Recent Advances in Deuteration Reactions†

“…Apart from dehalogenative deuteration, similar deuteration reactions with other leaving groups, such as –COOH, [ 53 ] –B(OH) 2 , [ 54 ] –Otf, [ 55 ] have been well explored. Ketonic carbonyl is not a current functional group easy to be departed but H/D exchange occurred at acidic α‐C—H bonds easily.…”