Highly Efficient Synthesis of Quinoxalinone-N-oxide via Tandem Nitrosation/Aerobic Oxidative C–N Bond Formation
摘要:
An efficient method for constructing quinoxalinone-N-oxides from cyanoacetanilides has been developed. This transformation can be achieved using inexpensive reagents and molecular oxygen under mild conditions, thus offering a practical pathway to quinoxalinone-containing pharmaceuticals such as ataquimast and opaviraline.
transition-metal-free one-pot sequence for the synthesis of 3-peroxy-substituted oxindoles from readily prepared 2-cyano-2-diazo-acetamides is reported. The two-step tandem process includes a highly efficient thermal intramolecular C–H-carbene insertion followed by a tetrabutylammonium iodide (TBAI) catalyzed radical C3-peroxy-functionalization. The protocol provides easy access to a new class of 3-cyano-3-
A new one-pot strategy for the synthesis of quinoxalin-2-ones from the tandem nitrosation/cyclization reaction of N-aryl cyanoacetamides with tert-butyl nitrite has been developed. The dehydrogenative N-incorporation is achieved through a sequence of nitrosation, tautomerization, and cyclization, affording quinoxalin-2-ones in moderate to good yields with good functional group tolerance.
Herein, we present a mild and efficient metal-free arylation of α-fluoro-α-nitroacetamides employing diaryliodoniumsalts. A broad range of diaryliodoniumsalts and α-fluoro-α-nitroacetamides containing sensitive functional groups was successfully employed in this protocol to yield the arylated products in good yields. The synthetic value of this novel protocol was further highlighted by extending
Chemospecific synthesis of 2-acetoxyindole-3-carbonitriles catalyzed by Cu(acac)2
作者:Shanyan Mo、Jianzhuo Tu、Jiaxi Xu
DOI:10.1007/s11172-016-1509-6
日期:2016.7
A chemospecific one-pot synthesis of easily isolable 2-acetoxyindole-3-carbonitriles was described. The intermediate 2-oxindole-3-carbonitriles successfully prepared from 2-cyano diazoacetanilides without isolation were treated with acetyl chloride and triethylamine to give 2-acetoxyindole-3-carbonitriles. The developed one-pot approach showed broad substrate scope.
Photoinduced, Copper-Catalyzed Enantioconvergent Alkylations of Anilines by Racemic Tertiary Electrophiles: Synthesis and Mechanism
作者:Hyungdo Cho、Hidehiro Suematsu、Paul H. Oyala、Jonas C. Peters、Gregory C. Fu
DOI:10.1021/jacs.1c12749
日期:2022.3.16
absence of light and catalyst, virtually no C–N bond formation is observed even upon heating to 80 °C. The mechanism of this new catalytic enantioconvergent substitution process has been interrogated with the aid of a wide array of tools, including the independent synthesis of proposed intermediates and reactivity studies, spectroscopic investigations featuring photophysical and EPR data, and DFT calculations
过渡金属催化烷基亲电子试剂被氮亲核试剂取代反应开始成为合成高级胺以及控制其立体化学的有力策略。在此,我们报道了一种易于获得的手性铜催化剂(市售组分)可以实现各种外消旋叔烷基亲电子试剂与苯胺亲核试剂的光诱导对映会聚偶联,从而在完全取代的立体中心生成具有良好 ee 的新 C-N 键产品的;尽管这种光诱导的铜催化偶联在 -78 °C 下进行,但在没有光和催化剂的情况下,即使加热到 80 °C 也几乎没有观察到 C-N 键形成。借助各种工具,包括拟议中间体的独立合成和反应性研究、以光物理和 EPR 数据为特征的光谱研究以及 DFT 计算,已经对这种新的催化对映收敛取代过程的机制进行了研究。这些研究导致在拟议的催化循环中鉴定了三种铜基中间体,包括手性三配位正式铜 (II)-苯胺基(DFT 分析指出其形式为铜(I)-苯胺基自由基)络合物,作为持久性自由基,与叔有机自由基偶联以产生具有良好对映选择性的所需