1255772-29-2Relevant academic research and scientific papers
Diversity in Heterocycle Synthesis Using α-Iminocarboxylic Acids: Decarboxylation Dichotomy
Hunjan, Mandeep Kaur,Laha, Joydev K.
, (2022/02/07)
Despite the structural similarity with imines, α-iminocarboxylic acids have seldom been used in heterocycles synthesis. The reactions of ortho-substituted anilines and arylglyoxylic acids in DMSO at 40 °C gave various benzo-fused five- to six-membered N-heterocycles in good to excellent yields. The reaction proceeds via intramolecular Michael addition of α-iminocarboxylic acids, generated in situ, with an ortho-substituted nucleophile, yielding an isolable unprecedented tetrahedral carboxylic acids, which upon decarboxylation without any aid of additional reagents forms the N-heterocycles. DMSO is crucial in this reaction, perhaps because of improved solubility and the ease of decarboxylation of these tetrahedral carboxylic acids. However, a copper-catalyzed reaction of ortho-substituted anilines and 2-bromoarylglyoxylic acids gave a dibenzo-fused seven-membered N-heterocycle under a basic reaction condition. Unlike intramolecular cyclization with α-iminocarboxylic acids in the first case, α-iminocarboxylic acid undergoes a competitive decarboxylation under the copper-catalyzed conditions, which upon subsequent heteroarylation form the heterocycles. Taken together, the study described herein represents two different modes of decarboxylation observed with α-iminocarboxylic acids, leading to the synthesis of divergent heterocycles and pharmaceuticals, which remained unexplored previously.
Metal-free sp3 C-H bond oxidation and functionalization of α-bromoketones to quinoxalinone, benzoxazinone, and benzothiazinone heterocyclic compounds
Chen, Xiuling,Guo, Fang,Qi, Hongxue,Tian, Haiying,Wei, Tianlong
, p. 1138 - 1148 (2021/06/21)
A series of heterocyclic compounds (benzothiazinones, benzoxazinones and quinoxalinones) were efficiently synthesized in excellent yields via α-bromoketones with o-substituted aniline (2-aminothiophenol, aryl-1,2-diamines and 2-aminophenol). This protocol accomplishes sp3 C-H bond oxidation and functionalization in one-pot without any metal catalyst.
Destruction and Construction: Application of Dearomatization Strategy in Aromatic Carbon-Nitrogen Bond Functionalization
Wang, Shuo-En,Wang, Linfei,He, Qiuqin,Fan, Renhua
, p. 13655 - 13658 (2015/11/11)
The formation of carbon-carbon bonds through the functionalization of aromatic carbon-nitrogen bonds is a highly attractive synthetic strategy in the synthesis of aromatic molecules. In this paper, we report a novel aromatic carbon-nitrogen bond functionalization reaction by using a simple dearomatization strategy. Through this process para-substituted anilines serve as a potential aryl source in the construction of a range of functionalized aromatic molecules, such as quaternary carbon centers, α-keto esters, and aldehydes.
Unexpected TFA-catalyzed tandem reaction of benzo[d]oxazoles with 2-oxo-2-arylacetic acids: Synthesis of 3-aryl-2H-benzo[b][1,4]oxazin-2-ones and cephalandole A
Yan, Shaoxi,Ye, Leping,Liu, Miaochang,Chen, Jiuxi,Ding, Jinchang,Gao, Wenxia,Huang, Xiaobo,Wu, Huayue
, p. 16705 - 16709 (2014/05/06)
A convenient and efficient method for the TFA-catalyzed synthesis of 3-aryl-2H-benzo[b][1,4]oxazin-2-ones via a tandem reaction of benzo[d]oxazoles with 2-oxo-2-arylacetic acids was reported for the first time. The efficiency of this transformation was demonstrated by compatibility with a wide range of functional groups. The synthetic utility of this method was confirmed by the synthesis of the natural product cephalandole A. Moreover, a plausible mechanism for the formation of 3-aryl-2H-benzo[b][1,4]oxazin-2-ones involving ring-opening and cyclization steps is proposed. The present synthetic route to 3-aryl-2H-benzo[b][1,4]oxazin-2-ones could be readily scaled up to gram quantity without difficulty.
Oxone-mediated oxidative carbon-heteroatom bond cleavage: Synthesis of benzoxazinones from benzoxazoles with α-oxocarboxylic acids
Wang, Hua,Yang, Hua,Li, Yiping,Duan, Xin-Hua
, p. 8720 - 8722 (2014/03/21)
A metal-free oxidative cleavage of benzoxazoles using Oxone as an oxidant has been developed. The in situ formed o-aminophenol has been proved to react successfully with α-oxocarboxylic acids affording the benzoxazinones in moderate to good yields. The Royal Society of Chemistry.
[Ir(P-OP)]-catalyzed asymmetric hydrogenation of diversely substituted C=N-containing heterocycles
Nunez-Rico, Jose Luis,Vidal-Ferran, Anton
supporting information, p. 2066 - 2069 (2013/06/04)
Iridium(I) complexes of enantiomerically pure phosphine-phosphite ligands ([Ir(Cl)(cod)(P - OP)]) efficiently catalyze the enantioselective hydrogenation of diverse C=N-containing heterocyclic compounds (benzoxazines, benzoxazinones, benzothiazinones, and quinoxalinones; 25 examples, up to 99% ee). A substrate-to-catalyst ratio as high as 2000:1 was reached.
An efficient synthetic protocol for quinoxalinones, Benzoxazinones, and benzothiazinones from 2-oxo-2-aryl-acetyl bromide precursors
Nagaraj, Muthupandi,Sathiyamoorthy, Sithuraj,Boominathan, Muthusamy,Muthusubramanian, Shanmugam,Bhuvanesh, Nattamai
, p. 1146 - 1151 (2013/10/21)
α-Bromoketones undergo selenium dioxide oxidation to yield reactive 2-oxo-2-arylacetyl bromides that are trapped by aryl-1,2-diamines, 1,2-aminophenol or 1,2-aminothiophenol to give quinoxalinones, benzoxazinones, and benzothiazinones, respectively, in go
The first general, highly enantioselective lewis base organocatalyzed hydrosilylation of benzoxazinones and quinoxalinones
Xue, Zhou-Yang,Jiang, Yan,Peng, Xiao-Zhi,Yuan, Wei-Cheng,Zhang, Xiao-Mei
supporting information; experimental part, p. 2132 - 2136 (2010/11/04)
The first general, highly enantioselective hydrosilylation of benzoxazinones and quinoxalinones has been developed. The chiral Lewis base organocatalysis that are readily accessible from (1S,2R)-ephedrine and (1R,2S)-ephedrine promoted the title reaction to afford various chiral dihydrobenzoxazinones and dihydroquinoxalinones with good yields as well as good enantioselectivities.
