Uncatalysed Preparation of α-Amino Phosphonates under Solvent Free Conditions

Abstract

A simple, efficient and environmentally friendly procedure has been developed for the three component coupling of carbonyl compounds, aromatic and aliphatic amines and dialkyl phosphites to produce α-amino phosphonates. The α-amino phosphonates are synthesised in high yields (74-97%) in a few minutes (1-3 min) by microwave irradiation under solvent-free conditions, avoiding the use of any catalyst.

Synthesis of alkyl α‐aminomethyl‐phenylphosphinates and N,N‐bis(alkoxyphenylphosphinylmethyl)amines by the microwave‐assisted Kabachnik–Fields reaction

“…[29] It was found that under solvent-free conditions there is no need for any catalyst. [30,31] The most efficient protocol for the condensation under discussion is the catalyst-and solvent-free microwave (MW)-assisted accomplishment. [32][33][34][35] As a modification, the double Kabachnik-Fields reaction has also been described for the synthesis of bis(aminophosphonates) or bis(aminophosphine oxides).…”

“…The alkyl α-alkylaminomethyl-phenylphosphinates (2ad, 5a-d, and 7a-d) are all new compounds that were characterized by 31 P, 13 C, and 1 H NMR, as well as high-resolution mass spectrometry.…”

“…Thus, nowadays greener variations of the phospha‐Mannich reaction have come to the front . It was found that under solvent‐free conditions there is no need for any catalyst . The most efficient protocol for the condensation under discussion is the catalyst‐ and solvent‐free microwave (MW)‐assisted accomplishment .…”

N-Benzyl and N-aryl bis(phospha-Mannich adducts): Synthesis and catalytic activity of the related bidentate chelate platinum complexes in hydroformylation

“…However, it was found that, especially under solvent-free conditions, there is no need for catalysts [7,8]. The efficiency could be further increased by the microwave (MW) technique [9e11].…”

An Efficient Green Synthesis of a New Class of α‐Aminophosphonates under Microwave Irradiation Conditions in the Presence of PS/PTSA

“…All of these reports are based on few model reactions . Later phospha‐Mannich condensation was further improvised in microwave‐heated solvent‐ and catalyst‐free conditions. Recently, all the microwave‐assisted KF reactions in a simple, straightforward, and most environmentally friendly way were revised elaborately under solvent‐ and catalyst‐free reaction conditions .…”