Mechanism of Phosphorus–Carbon Bond Formation in the Amidoalkylation of Phosphonous Carboxylic Acids
作者:Maxim E. Dmitriev、Sofia R. Golovash、Alexei V. Borodachev、Valery V. Ragulin
DOI:10.1021/acs.joc.0c02259
日期:2021.1.1
An unusual greater reactivity of phosphonous propionic acids was found in comparison with phosphonous propionic esters in carbamate version of Kabachnik–Fields reaction. Compounds of tricoordinated phosphorus generated in situ during the amidoalkylation of hydrophosphorylic compounds in acetyl chloride/acetic anhydride mixture were found by 31P NMR analysis. A hypothesis is proposed about the generation
与氨基甲酸酯形式的Kabachnik–Fields反应相比,亚磷酸丙酸的反应性比亚磷酸丙酯高。通过31 P NMR分析发现在乙酰氯/乙酸酐混合物中氢磷酸化合物的酰胺烷基化过程中原位产生的三配位磷化合物。提出了关于原位螺正膦生成的假设,以解释所研究反应中磷-碳键形成的机理。
Acyloxy derivatives of trivalent phosphorus in amidoalkylation of hydrophosphoryl compounds
作者:M. E. Dmitriev、V. V. Ragulin
DOI:10.1134/s1070363213100150
日期:2013.10
In order to model the previously suggested mechanism of the P-C bond formation via the Arbuzov reaction, we have studied the interaction of diethylacylphosphite (prepared beforehand as well as generated in situ from tetraethylpyrophosphite) with the in situ generated acyliminium cation. Various conditions of in situ generation of acylphosphite derivatives of P(III) from hydrophosphoryl compounds and acyliminium ions from N,N'-alkylidenebiscarbamates have been investigated: solvent nature, acid catalyst, and the reagents mixing order). The results obtained have confirmed the suggested mechanism of three-component reaction of amidoalkylation of hydrophosphoryl compounds with the formation of P-C bond via the Arbuzov reaction of in situ formed intermediates.
HBF4·OEt2: An efficient fluorinated acid catalyst for the one-pot synthesis of secondary and tertiary N-homoallylic carbamates
An efficient method for the one-pot synthesis of secondary and tertiary N-homoallylic carbamates using catalytic amount of HBF4 center dot OEt2 is described. The reaction proceeded smoothly to afford the corresponding N-homoallylic carbamates in good to high yields. Operationally simple and easily scalable features make this method more practical over existing methods. Use of HBF4 center dot OEt2 as an acid catalyst also proves the catalytic activity of fluorinated acid catalyst in this important organic transformation. (C) 2014 Elsevier B.V. All rights reserved.