Direct C−H Trifluoromethylation of Quinoxalin‐2(1H)‐ones under Transition‐Metal‐Free Conditions

Abstract

Disclosed herein is a direct C−H trifluoromethylation of quinoxalin‐2(1H)‐ones with sodium trifluoromethanesulfinate. This protocol affords a series of 3‐trifluoromethylquinoxalin‐2(1H)‐one derivatives in moderate to excellent yields under transition‐metal‐free conditions. The present methodology features utilization of the inexpensive trifluoromethyl source without transition‐metal‐catalysts, mild reaction conditions and high functional group tolerance, which promises a convenient and efficient access to pharmaceutically interesting quinoxalinones.magnified image

Phenyliodonium Diacetate Mediated Carbotrifluoromethylation of Quinoxalin‐2(1H)‐ones

“…Recently, Zhao and co-workers have reported the method to obtain 3-trifluoromethylquinoxalin-2(1H)-ones use CF 3 SO 2 Na and PhI(OTFA) 2. [11] Herein, we would like to disclose a concise and direct trifluoromethylation of quinoxalin-2(1H)-ones at C3 position by using TMSCF 3 as trifluoromethyl source to give 3-trifluoromethylquinoxalin-2(1H)-ones.…”

Copper‐Catalyzed Direct Carbamoylation of Quinoxalin‐2(1H)‐ones with Hydrazinecarboxamides Under Mild Conditions

“…In view of their remarkable importance, the direct functionalization of C3 position of quinoxalin-2(1H)-one has been extensively studied in recent organic synthesis, for instance (Scheme 1a), etherification, [8] amination, [9] alkylation, [10] benzylation, [11] arylation, [12] acylation, [13] phosphonation, [14] trifluoromethylation. [15] Although remarkable achievements have been obtained, the direct C3-H carbamoylation of quinoxalin-2(1H)-tions with a broad range of substrates and functional group tolerance. The present methodology affords a convenient and practical access to pharmaceutically active 3-carbamoylquinoxalin-2(1H)-one derivatives.…”

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

“…[2c] Therefore, it is not surprising that much effort has been devoted to developing methods for the synthesis of quinoxalin-2-one derivatives. [9] However, the efficient and convenient mean for introducing the difluoromethylene (CF 2 ) group into the C-3 position of quinoxalin-2-ones is still scarce. [3] In recent years, the direct CÀ H functionalization of available quinoxalin-2 (1H)-ones has been regarded as an alternative and efficient approach to 3-functional quinoxalin-2(1H)ones.…”

“…UPDATES asc.wiley-vch.de tigation on catalyst loading showed that the suitable amount of [Cu(CH 3 CN) 4 ]PF 6 was 7.5 mol %, and the desired product 3 a was obtained in 68% yield (Table 1, entries [8][9][10][11]. UPDATES asc.wiley-vch.de tigation on catalyst loading showed that the suitable amount of [Cu(CH 3 CN) 4 ]PF 6 was 7.5 mol %, and the desired product 3 a was obtained in 68% yield (Table 1, entries [8][9][10][11].…”