Phenanthrenequinone (PQ) catalyzed cross-dehydrogenative coupling of alkanes with quinoxalin-2(1H)-ones and simple N-heteroarenes under visible light irradiation

Abstract

A direct and convenient strategy to 3-alkylquinoxalin-2(1H)-ones and other alkyl N-heteroarenes via a photocatalyzed alkylation of quinoxalin-2(1H)-ones and simple N-heterocycles with commercially available, low-cost alkanes under ambient conditions using phenanthrenequinone...

Decarbonylative C3‐Alkylation of Quinoxalin‐2(1H)‐Ones with Aliphatic Aldehydes via Photocatalysis

“…According to the above mechanistic studies and literature report, [11,15a] a plausible pathway for the reaction was proposed with N ‐methylquinoxalin‐2(1 H )‐ones and pivalaldehyde (Scheme 6). First, PQ (PC 1 ) was excited to its excited state PQ* under blue LED irradiation.…”

Rose Bengal Immobilized on Cellulose Paper for Sustainable Visible‐Light Photocatalysis

“…The α‐C−H functionalization of ethers under mild and metal‐free conditions is an attractive and appealing but still underexplored strategy to assemble complex structural motifs [42–47] . In our hands, Cell‐RB successfully catalyzed the coupling of 1‐methylquinoxalin‐2(1H)‐one 6 with THF 7 a and 2‐methyl‐THF 7 b in the presence of t ‐BuOOH as the oxidant and DABCO as the base at room temperature (Scheme 3).…”

“…The α-CÀ H functionalization of ethers under mild and metal-free conditions is an attractive and appealing but still underexplored strategy to assemble complex structural motifs. [42][43][44][45][46][47] In our hands, Cell-RB successfully catalyzed the coupling of 1-methylquinoxalin-2(1H)-one 6 with THF 7 a and 2methyl-THF 7 b in the presence of t-BuOOH as the oxidant and DABCO as the base at room temperature (Scheme 3). With 2methyl-THF, the α-CÀ H functionalization occurred on the most substituted position presumably due to the higher stability of the corresponding radical intermediate.…”

Photoinduced Decarboxylative C3–H Alkylation of Quinoxalin-2(1H)-ones

“…1 3-Cyclohexylquinoxalin-2(1H)-one (3ao). 23 Following the general procedure two independent reactions of 1m (0.15 mmol, 41 mg) and 2p (0.1 mmol, 14.6 mg) afforded 3ao as a white solid (66%, 15 mg). 1…”

“…. 23 Following the general procedure two independent reactions of 1o (0.15 mmol, 42.8 mg) and 2a (0.1 mmol, 16 mg) afforded 3o as a crystalline off white solid (84%, 21.3 mg). 1 H NMR (500 MHz, CDCl 3 ) δ 7.82 (d, J = 7.95 Hz, 1H), 7.47 (t, J = 8.5 Hz, 1H), 7.30 (t, J = 8.25 Hz, 1H), 7.27 (d, J = 8.3 Hz, 1H), 3.68 (s, 3H), 3.32−3.29 (m, 1H), 2.47 (brs, 1H), 2.37 (brs, 1H), 2.22−2.17 (m, 1H), 1.66−1.49 (m, 5H), 1.36−1.31 (m, 1H), 1.11−1.09 (m, 1H).…”