Decatungstate-photocatalyzed direct coupling of inert alkanes and quinoxalin-2(1H)-ones with H₂ evolution

Abstract

A tetrabutylammonium decatungstate (TBADT)-photocatalyzed direct coupling of inert alkanes and quinoxalin-2(1H)-ones with H2 evolution was developed at room temperature. The present transformation achieved the direct C(sp3)-H/C(sp2)-H coupling under noble metal-free,...

Visible-light-promoted C(sp3)–H thiolation of aliphatic ethers with thiosulfonates

“…Based on the above explorations and previous literature, 7,8 a proposed mechanism for this reaction was postulated, as shown in Scheme 5. Initially, Na 2 -EY (Na 2 -eosin Y) is photoexcited to its excited state [Na 2 -EY]* under the irradiation of blue LED irradiation.…”

“…In the past decade, visible-light-promoted synthetic methodology has earned significant interest in organic chemistry due to its mild reaction conditions and clean energy source. 7 In 2016, Wang and Li's group reported a visible-light-induced α-C(sp 3 )–H thiolation of aliphatic ethers in the presence of acridine red and 4 equiv. of TBHP under green light irradiation (Scheme 1b).…”

Visible-Light-Promoted Deoxygenative Alkylation of Quinoxalin-2(1H)-ones with Activated Alcohols

“…In recent years, photoredox-catalyzed radical alkylation of quinoxalin-2­(1 H )-ones has emerged as a preeminent handle for the versatile, functional group-tolerant synthesis of 3-alkylated quinoxalin-2­(1 H )-one derivatives . A series of alkyl radical precursors, such as hydrocarbons, halohydrocarbons, aldehydes, carboxylic acids, redox-active esters, alkylborates, etc., have been elegantly employed to introduce structurally diverse alkyl units into quinoxalin-2­(1 H )-ones under mild conditions (Scheme a). Despite these advances, there appear to be no reports of deoxygenative alkylation of quinoxalin-2­(1 H )-ones under visible-light irradiation using naturally abundant and widely occurring alcohols as alkyl radical precursors upon C–O bond cleavage.…”

Bromine radical enhanced stoichiometric pyridylation of alkylarenes and diarylmethanes at room temperature

“…Strategies that employ industrial feedstocks to avoid sensitive organometallic reagents, strong reductants, and the high loading of transition-metal catalysts to provide high-value products are highly attractive, especially for the modification of existing drug molecules. 4…”