2‐diazaphosphorine (BEMP) at room temperature. Depending on the substitution pattern and nature of the aryl moiety, a switch toward the formation of imines can be observed. The mechanistic framework is put to scrutiny by experimental and theoretical studies, pointing to the formation of a nitroso aldol intermediate, whose fate toward one of the competing pathways, namely hydride transfer or elimination
The reaction between arylazo p-tolyl sulfones la-f (Ar-N=N-SO2p-Tol) and the potassium salts of some active-methylene compounds (CH2XY: X, Y = CN, COOEt) represents an example of unprecedented behaviour of azosulfones and effectively leads, depending on the nucleophile, to either unsymmetrical (6–8) or symmetrical (9) tetrasubstituted ethylenes. Of particular interest is the possibility to synthesize
芳基偶氮对甲苯基砜la-f(Ar-N = N-SO 2 p - Tol)与某些活性亚甲基化合物(CH2XY:X,Y = CN,COOEt)的钾盐之间的反应代表了前所未有的例子偶氮砜的行为,并根据亲核试剂有效地导致不对称(6-8)或对称(9)四取代的乙烯。特别令人感兴趣的是,可以在高收率和温和条件下合成极性乙烯lArNHCX = CXY:X = Y = CN(6)或X = COOEt,Y = CN(7)],其中有些不容易获得。实验证据支持了涉及连续缩合过程的机理。
Access to highly functionalized imidazolones bearing α-amino acid esters <i>via</i> KOH-promoted annulation of amidines, nitrosoarenes and malonic esters
作者:Wenhui Li、Jie Xin、Pingan Zhai、Jianying Lin、Shuangping Huang、Wenchao Gao、Xing Li
DOI:10.1039/d1ob00930c
日期:——
α-amino acid esters through KOH-mediated one-pot three-component annulation of amidines, nitrosoarenes and malonic esters is reported. This reaction features broad substrate scope, a cheap and readily available promoter, good to high yields for most substrates and mild reaction conditions. The mechanism study shows that the KOH-mediated formation of the imine intermediate via the reaction of nitrosoarenes