Synthesis of N,N‐Bis(dialkoxyphosphinoylmethyl)‐ and N,N‐Bis(diphenylphosphinoylmethyl)‐β‐ and γ‐amino acid Derivatives by the Microwave‐Assisted Double Kabachnik–Fields Reaction

Abstract

The title compounds were synthesized by the microwave‐assisted, mostly solvent‐free bis Kabachnik–Fields condensation of β‐alanine and γ‐aminobutyric acid or their esters with formaldehyde and >P(O)H species, such as dialkyl phosphites and diphenylphosphine oxide.

A study on the deoxygenation of trialkyl‐, dialkyl‐phenyl‐ and alkyl‐diphenyl phosphine oxides by hydrosilanes

“…It is a green chemical approach to substitute catalysts by MW irradiation. We experienced that in heterogeneous phase C‐alkylations, and in Kabachnik‐Fields reactions, the catalysts could be omitted under MW conditions. It was shown above that this approach was utilized in the TMDS‐ and PMHS‐promoted deoxygenations .…”

6. Synthesis of α-aminophosphonates by the Kabachnik–Fields reaction and by the Pudovik reaction

“…According to the literature, double Kabachnik-Fields reactions are usually carried out in various solvents, without any catalyst [84][85][86][87][88][89][90][91]. Nowadays, green chemical approaches, such as the catalyst-and solvent-free MW-assisted syntheses, have also became more and more popular [77,[92][93][94][95][96].…”

<strong>Synthesis of &alpha;-aminophosphonates and related derivatives under microwave conditions</strong>

“…α-, β-and γ-Amino acids and esters were also suitable amine components in the condensation. The corresponding bis(dialkoxyphosphonylmethyl)amino acid derivatives (8) were obtained in yields of 61-97% [29,30].…”

“…The double Kabachnik-Fields condensations were also carried out applying secondary phosphine oxides (Scheme 3) [26][27][28][29][30]. To overcome the heterogeneity of the reaction mixture, the reactions were carried out in acetonitrile.…”