A Green Approach to the Synthesis of α-Amino Phosphonate in Water Medium: Carbene Insertion into the N–H Bond by Cu(I) Catalyst

Abstract

Synthesis of amino phosphonates is more important owing to their significant applications in the biological systems. There are few methods already known in the literature to make these molecules; however, known methods have their own disadvantages. In this regard, synthesis of different kinds of amino phosphonates have been achieved via phosphonate substituted carbene insertion into the N-H bond of aniline catalyzed by readily available copper salt under mild reaction conditions in water. In order to find an efficient catalyst for carbene insertion reaction in neat water, a large number of transition metal catalysts were screened, and we found that the [Cu(CHCN)]ClO was the best catalyst under employed reaction conditions. Using this environmentally benign methodology (copper catalyzed reaction in water), a large number of biologically important amino phosphonates have been synthesized, isolated (37 examples), and characterized using standard analytical and spectroscopic techniques.

Synthesis of Amido Esters and Amido Phosphonates through Carbonylation of Diazo Compounds Followed by Nucleophilic Addition Reaction

“…[37][38][39][40] TLC analysis was performed on precoated silica gel 60 F 254 plates, and the developed plates were visualized under UV light (254 nm). All solvents were distilled and stored under nitrogen prior to use according to standard procedures.…”

“…All diazo compounds were prepared by applying the standard reported procedures. [37][38][39][40] TLC analysis was performed on precoated silica gel 60 F 254 plates, and the developed plates were visualized under UV light (254 nm). Column chromatography was performed on silica gel (100-200 mesh).…”

“…Characterization of these compounds was achieved by using standard spectroscopic and analytical techniques as well as crystal structure analysis for four of the products. [34][35][36] Considering the importance of amido esters and amido phosphonates, and in continuation of our research on carbenes, [37][38][39][40] we herein report an efficient method for the synthesis of amido esters and amido phosphonates that proceeds through the carbonylation of carbenes by using a nongaseous CO source followed by a nucleophilic addition reaction using different amines. [21,26] The synthesis of ketenes by the carbonylation of carbenes using carbon monoxide offers several advantages when other known methods suffer from low yields and harsh reaction conditions.…”

“…[31][32][33] Although there are difficulties in the handling of CO, few alternate methods have been developed for the carbonylation of alkyl or aryl halides by using nongaseous carbon monoxide sources. [34][35][36] Considering the importance of amido esters and amido phosphonates, and in continuation of our research on carbenes, [37][38][39][40] we herein report an efficient method for the synthesis of amido esters and amido phosphonates that proceeds through the carbonylation of carbenes by using a nongaseous CO source followed by a nucleophilic addition reaction using different amines.…”

Synthesis of Diesters through Carbonylation of Diazo Compounds Followed by Alcohol Addition

“…Transition metal catalyzed carbonylation of metal carbene with carbon monoxide is one of the easiest methods for the synthesis of ketenes . However carbonylation using CO can also be done efficiently by using some non‐gaseous CO sources such as metal carbonyls and organic carbonyl compounds . The ketene generated from carbonylation of metal carbene can undergo nucleophilic addition with alcohol to produce the corresponding diester.…”