Visible-Light-Promoted Transition-Metal-Free Phosphinylation of Heteroaryl Halides in the Presence of Potassium tert-Butoxide

Abstract

A novel visible-light-promoted C−P bond formation reaction in the absence of both transition metal and photoredox catalysts is disclosed. By employing easily available and inexpensive heteroaryl chlorides/bromides as substrates, a variety of heteroaryl phosphine oxides were obtained in moderate to good yields. This strategy provides a simple and efficient route to heteroaryl phosphine oxides.Letter pubs.acs.org/OrgLett

Visible light-mediated C P bond formation reactions

“…Note that, this is the first reported example of the formation of C-heteroatom bonds by using photoredox/nickel dual catalytic system. The transition metal-free process of this reaction was recently realized by Yu, Che and co-workers [68].…”

Recent Advances in the Construction of Phosphorus‐Substituted Heterocycles, 2009–2019

“…Visible‐light photoredox catalysis has become a powerful and useful method for C−P bond construction via a photoinduced electron transfer process, which often requires suitable photocatalysts and oxidants . In 2018, Yu and Che established a photoredox catalyst‐free visible light‐mediated C( sp 2 )−P bond formation reaction from heteroaromatic chlorides or bromides . The use of t‐ BuOK as base and 7 W blue LED as light source allowed the formation of phosphorylated pyridines 30 at root temperature in 6 h. According to various experiments, a tentative mechanism was proposed as shown in Scheme .…”

Photochemical Strategies for Carbon–Heteroatom Bond Formation

“…SET results in a nitrogen centered radical that reacts with diarylphosphanes to form 160 (Scheme , A) . Chloropyridines ( 162 ) were activated towards C–P couplings by formation of an EDA complex with potassium tert ‐butoxide (Scheme , B) . Blue light irradiation induced the formation of two radical species.…”