Mechanochemical Synthesis of 2‐Arylquinoxalines and 3‐Arylquinoxalin‐2(1H)‐ones via Aryldiazonium Salts

Abstract

A green synthesis strategy of 2‐arylquinoxalines and 3‐arylquinoxalin‐2(1H)‐ones via ball milling, which could avoid copious solvent waste, was accomplished in this work. Aryl radicals were produced from aryldiazonium salts by using a solvent‐free or catalyst‐free single electron transfer process induced by mechanical force, affording a series of 2‐arylquinoxalines and 3‐arylquinoxalin‐2(1H)‐ones with 28%–85 yield.

Piezoelectrically Mediated Reactions: From Catalytic Reactions to Organic Transformations

“…The results show that MeCN, DMF and acetone can be as the alternatives of LAG to improve the yield (Table 2). [ 52 ] In contrast, nonpolar solvent, such as hexane, showed little improvement in the yield (1%). A similar trend was observed in the piezoelectrically mediated polymerization by ultrasound.…”

“…[ 3+2] annulation [67] BaTiO3 nanoparticles Ball Milling (35 Hz) C(sp 2 )-H arylation [68] BaTiO3 nanoparticles Ball Milling (30 Hz) Arylation of quinoxaline and quinoxalin-2(1H)-ones [52] BaTiO3 nanoparticles Ball Milling (550 r/min) Dicarbonylation and oxidation [69] BaTiO3@graphene Ultrasound (40 kHz, 200 W) Decomplexation of Cu-EDTA [70] BaTiO3@Au.…”

“…Piezoceramics is an important class of piezoelectric materials with the characteristics of high piezoelectrical coefficient. PZT-based Table 2 Optimization of the reaction medium (LAG) [52] Entry a LAG Time/h Yield b /% Reaction conditions: 1a (0.45 mmol), 2a (0.3 mmol), BaTiO3 (1.5 mmol), LAG (0.12 μL/mg). b Isolated yields.…”

“…This strategy can be extended to the arylation of quinoxalin-2(1H)-one with aryldiazonium salts. [52] The substrate scope of aryldiazonium salts and quinoxalin-2(1H)-ones was explored. The results showed moderate to good yields (54%-83%) for the synthesis of 3-arylquinoxalin-2(1H)-one scaffold.…”

Visible-light-photocatalysis driven denitrogenative/radical 1,3-shift of benzotriazole: access to 3-aryl-aminoquinoxalin-2(1H)-one scaffolds

“…It is widely known that the direct C–H functionalization of C3-quinoxalin-2(1 H )-ones is one of the most convenient and feasible methods to obtain these molecules. In this context, most of the current reports concentrate on the C–C bond formation of quinoxalin-2(1 H )-ones via C–H alkylation, 2 arylation reaction 3 and others. 4 Nevertheless, the direct amination of quinoxalin-2(1 H )-ones to forge C–N bonds affording 3-aminoquinoxalin-2(1 H )-ones is underdeveloped, but in great demand (Scheme 1a).…”