Pd(TFA)₂-catalyzed direct arylation of quinoxalinones with arenes

Abstract

Pd(TFA)2-catalyzed cross-dehydrogenative coupling reaction for the direct C-3 arylation of quinoxalin-2-ones with arenes is described.

Metal‐Free C3 Hydroxylation of Quinoxalin‐2(1H)‐ones in Water

“…[2] Traditionally, Nfunctionalized quinoxaline-2,3-diones are prepared through base-promoted condensation reaction between mono N-substituted 1,2-diaminobenzenes and oxalyl chloride (or ethyl chloroglyoxalate) (Scheme 1a). Given the readily available quinoxalin-2(1H)-ones, significant progress has been achieved on the CÀ H bond functionalization of quinoxalin-2(1H)-ones, including the regioselective alkylation, [3] alkoxylation, [4] arylation, [5] acylation, [6] amination, [7] trifluoromethylation [8] and phosphonation reaction [9] . Given the readily available quinoxalin-2(1H)-ones, significant progress has been achieved on the CÀ H bond functionalization of quinoxalin-2(1H)-ones, including the regioselective alkylation, [3] alkoxylation, [4] arylation, [5] acylation, [6] amination, [7] trifluoromethylation [8] and phosphonation reaction [9] .…”

“…[2a,b] However, from a practical and eco-friendly point of view, those procedures still suffer from some drawbacks, such as the difficulties of preparation and isolation of mono N-substituted substrates, the usage of toxic oxalyl chloride and volatile organic solvent, and harsh reaction conditions. Given the readily available quinoxalin-2(1H)-ones, significant progress has been achieved on the CÀ H bond functionalization of quinoxalin-2(1H)-ones, including the regioselective alkylation, [3] alkoxylation, [4] arylation, [5] acylation, [6] amination, [7] trifluoromethylation [8] and phosphonation reaction [9] . During the past decade, water has received much attention as the expected reaction medium for organic reactions due to safety, cost and environmental concerns.…”

Copper‐Catalyzed Regio‐ and Stereoselective Oxidative Vinylsulfonylation of Quinoxalinones with Alkynes and Sulfonyl Hydrazides

“…Recently, the several catalytic methods have been devoted for functionalization of quinoxalin‐2(1 H )‐ones at C3 position via C3−H arylation, [13] alkylation, [14] acylation, [15] alkoxycarbonylation, [16] amination, [17] amidation, [18] or phosphonation [19] . We have previously reported direct oxidative transition‐metal‐catalyzed and metal‐free reactions of quinoxalin‐2( H )‐ones with arenes [20] or arylhydrazines, [21] which provides the 3‐arylated quinoxalin‐2( H )‐ones. Several multi‐component reactions of quinoxalinones have also been recently reported [22] .…”

Recent Advances on the Catalytic Functionalization of Quinoxalin- 2(1H)-ones via C-H Bond Activation

“…In 2019, Lee and coworkers developed a Pd(TFA) 2 -catalyzed cross-dehydrogenative coupling (CDC) reaction for the direct C-3 arylation of quinoxalin-2(1H)-ones with arenes (Scheme 22). [50] A wide array of functionalities, including highly sensitive allyl and benzyl group substituted quinoxalin-2(1H)-ones, are readily assembled with arenes containing electron-donating and electron-withdrawing groups in this CDC reaction. Highly regioselective products were produced in good yields with stronger electron-donating groups than toluene and densely substituted arenes as coupling partners.…”