Copper‐Catalyzed C3−H Difluoroacetylation of Quinoxalinones with Ethyl Bromodifluoroacetate

Abstract

A copper-catalyzed direct CÀ H difluoroacetylation of quinoxalinones at the C-3 position with ethyl bromodifluoroacetate has been developed. In this reaction, diverse difluoroacetylated quinoxalin-2(1H)-ones with a wide range of functional groups could be obtained in moderate to good yields, using cheap, commercially available reagents. This protocol would offer a meaningfully synthetic method for pharmacologically interesting difluoroacetylated quinoxalin-2(1H)-one derivatives.

Synthesis of Chiral 5‐Aryl‐2‐oxazolidinones via Halohydrin Dehalogenase‐Catalyzed Enantio‐ and Regioselective Ring‐Opening of Styrene Oxides

“…[9] Recently, we have developed a biocatalytic route to 4-aryl-2-oxazolidinones via cyanate-mediated ring-opening of aromatic epoxides using a highly C α -position regioselective HHDH. [19] Hence this study also provided an biocatalytic approach for regiocomplementary preparation of aryl-substituted-2-oxazolidinones from aromatic epoxides.…”

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

“…Recently, a synthetic method for difluoroacetylated quinoxalin-2(1 H )-one derivatives was presented by the same group [189]. The direct difluoroacetylation of diverse quinoxalinones with a wide range of functional groups proceeded regioselectively at the C-3 position with ethyl bromodifluoroacetate under copper catalysis (Scheme 115).…”

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

“…Some bioactive molecules containing quinoxalin-2(1 H )-one skeleton, such as Compounds 1 - 3 , also show potential applications in medicinal chemistry fields (Meyer et al, 2006 ; Khattab et al, 2015 ; Qin et al, 2015 ) ( Figure 1A ). Because of their synthetic usefulness and potential biological importance, the introduction of functional groups into the C3-position of the quinoxalin-2(1 H )-ones has already become a research hotspot, and various protocols for the direct C3-H functionalization of quinoxalin-2(1 H )-ones have been reported (Ebersol et al, 2019 ; Gu et al, 2019 ; Hong et al, 2019 ; Li et al, 2019 ; Peng et al, 2019 ; Rostoll-Berenguer et al, 2019 ; Teng et al, 2019 ; Wang et al, 2019a , 2020 ; Xie et al, 2019b ; Zhao et al, 2019 ; Zheng and Studer, 2019 ; Tian et al, 2020 ; Yuan et al, 2020 ). In particular, the C3-H functionalization of quinoxalin-2(1 H )-ones involving hypervalent iodine reagents has drawn wide attention for the aforementioned advantages of hypervalent iodine reagents, mainly including arylation (Paul et al, 2017 ; Yin and Zhang, 2017 ), trifluoromethylation (Wang et al, 2018 ; Xue et al, 2019a ), alkylation (Wang et al, 2019b ; Xie et al, 2019a ; Xue et al, 2019b ; Shen et al, 2020 ), and alkoxylation (Xu et al, 2019 ; Yang et al, 2019 ) of quinoxalin-2(1 H )-ones, which provide convenient and environmentally friendly means for the synthesis of 3-substituted quinoxalinone derivatives.…”