5495-09-0Relevant articles and documents
Facile Synthesis and Bioactivity of Novel N,N′-disubstituted-1,2,3,4-tetrahydroquinoxalines
Fu, Ying,Wang, Jing-Yi,Chen, Wen-Geng,Li, Yu,Zhao, Li-Xia,Gao, Shuang,Ye, Fei
, p. 3023 - 3029 (2017/10/03)
A series of novel N,N'-disubstituted-1,2,3,4-tetrahydroquinoxalines were designed and synthesized by cyclization and acylation. The structures of all the novel compounds were confirmed by IR, 1H NMR, 13C NMR, and high-resolution mass
Additive effects of amines on asymmetric hydrogenation of quinoxalines catalyzed by chiral iridium complexes
Nagano, Takuto,Iimuro, Atsuhiro,Kita, Yusuke,Mashima, Kazushi,Schwenk, Rino,Togni, Antonio,Ohshima, Takashi
supporting information, p. 11578 - 11592,15 (2012/12/12)
The additive effects of amines were realized in the asymmetric hydrogenation of 2-phenylquinoxaline, and its derivatives, catalyzed by chiral cationic dinuclear triply halide-bridged iridium complexes [{Ir(H)[diphosphine]} 2(μ-X)3]X (diphosphine=(S)-2,2'-bis(diphenylphosphino)- 1,1'-binaphthyl [(S)-BINAP], (S)-5,5'-bis(diphenylphosphino)-4,4'-bi-1,3- benzodioxole [(S)-SEGPHOS], (S)-5,5'-bis(diphenylphosphino)-2,2,2',2'- tetrafluoro-4,4'-bi-1,3-benzodioxole [(S)-DIFLUORPHOS]; X=Cl, Br, I) to produce the corresponding 2-aryl-1,2,3,4-tetrahydroquinoxalines. The additive effects of amines were investigated by solution dynamics studies of iridium complexes in the presence of N-methyl-p-anisidine (MPA), which was determined to be the best amine additive for achievement of a high enantioselectivity of (S)-2-phenyl-1,2,3,4-tetrahydroquinoxaline, and by labeling experiments, which revealed a plausible mechanism comprised of two cycles. One catalytic cycle was less active and less enantioselective; it involved the substrate-coordinated mononuclear complex [IrHCl2(2-phenylquinoxaline){(S)-BINAP}], which afforded half-reduced product 3-phenyl-1,2-dihydroquinoxaline. A poorly enantioselective disproportionation of this half-reduced product afforded (S)-2-phenyl-1,2,3,4-tetrahydroquinoxaline. The other cycle involved a more active hydride-amide catalyst, derived from amine-coordinated mononuclear complex [IrCl2H(MPA){(S)-BINAP}], which functioned to reduce 2-phenylquinoxaline to (S)-2-phenyl-1,2,3,4-tetrahydroquinoxaline with high enantioselectivity. Based on the proposed mechanism, an IrI-JOSIPHOS (JOSIPHOS=(R)-1-[(Sp)-2-(dicyclohexylphosphino)ferrocenylethyl] diphenylphosphine) catalyst in the presence of amine additive resulted in the highest enantioselectivity for the asymmetric hydrogenation of 2-phenylquinoxaline. Interestingly, the reaction rate and enantioselectivity were gradually increased during the reaction by a positive-feedback effect from the product amines. Copyright
A rapid and efficient method for the reduction of quinoxalines
McKinney, Andrew M.,Jackson, Kevin R.,Salvatore, Ralph Nicholas,Savrides, Elena-Maria,Edatte, Mary Jane,Gavin, Terrence
, p. 1031 - 1034 (2007/10/03)
Mono and di-substituted alkyl and aryl quinoxalines are rapidly reduced in high yield to their respective 1,2,3,4-tetrahydro-derivatives by borane in THF solution. In the case of the 2,3-di-substituted compounds, reduction is stereoselective yielding excl
3-ARYL-1,2-DIHYDROQUINOXALINES
Kolos, N.N.,Insuasti, B.,Kiroga, Kh.,Orlov, V.D.
, p. 918 - 922 (2007/10/02)
The reaction between o-phenylenediamine and its 4-chloro- and 3,5-dichloro-derivatives and 4-substituted ω-bromoacetophenones gives 1,2-dihydroquinoxalines.It has been found that the preferred course of the reaction under basic catalytic conditions involv