The C3-H Bond Functionalization of Quinoxalin-2(1H)-Ones With Hypervalent Iodine(III) Reagents

Abstract

The modification of quinoxalin-2(1H)-ones via direct C-H bond functionalization has begun to receive widespread attention, due to quinoxalin-2(1H)-one derivatives' various biological activities and pharmaceutical properties. This mini review concentrates on the accomplishments of arylation, trifluoromethylation, alkylation, and alkoxylation of quinoxalin-2(1H)-ones with hypervalent iodine(III) reagents as reaction partners or oxidants. The reaction conditions and mechanisms are compared and discussed in detail.

Photo-Induced Cross-Dehydrogenative Alkylation of Heteroarenes with Alkanes under Aerobic Conditions

“…The reaction conditions of CDC were optimized by evaluating the photocatalyst, additive, proton source, solvent, and reaction time (Table and the Supporting Information, Table S1–S6). The target product ( 3 ) was obtained in 87% yield by reacting quinoxalin-2­(1 H )-one ( 1a ) (0.2 mmol) with cyclohexane ( 2a ) (15 equiv), CeCl 3 (5 mol %), Bu 4 N + Cl – (20 mol %), CF 3 CH 2 OH (50 mol %), and CH 3 CN (1.0 mL) under 405 nm light-emitting diode (LED) (10 W) irradiation for 9 h (Table , entry 1). In the absence of CeCl 3 or visible light, no desired product was generated (Table , entries 2 and 3).…”

“…All alkanes and heteroarenes in Table were purchased from Energy Chemical. All quinoxalin-2­(1 H )-ones are known compounds and were prepared according to the corresponding literature. , All products were purified by silica gel (200–300 mesh) column chromatography using petroleum ether (PE) (60–90 °C) and ethyl acetate (EA) as the eluent …”

Visible‐light‐promoted Radical Cyclization/Arylation Cascade for the Construction of α,α‐Difluoro‐γ‐Lactam‐Fused Quinoxalin‐2(1H)‐Ones

“…[ 2‐3 ] Recently, this family of heterocyclic compounds has been successfully constructed by the direct C—H functionalization of easily available quinoxalin‐2(1 H )‐ones, such as arylation, alkylation, acylation, alkoxylation, and amidation, which provide an efficient and atom‐ economic strategy for their construction. [ 4‐6 ] To modify the chemical, physical, and biological properties of quinoxalin‐2(1 H )‐ones, the introduction of fluoroalkyl groups, such as –CF 3 , –CF 2 CO 2 Et, and –CF 2 H, was also developed via a radical oxidative‐coupling strategy in recent years (Scheme 1). [ 7 ]…”

Palladium-Catalyzed Organic Reactions Involving Hypervalent Iodine Reagents

“…[10][11][12][13][14][15][16][17][18]. The functionalization of carbonyl compounds [19,20], cyclization [21][22][23][24], oxidative rearrangements [25][26][27], alkene difunctionalizations [28][29][30][31], and atom-transfer reactions [32], in the presence of hypervalent iodine compounds as reagents or catalysts, is now well established. The capacity of hypervalent iodine reagents to operate as both oxidant and ligand transfer reagents is the key to the substantial success made in this area [33,34].…”