Synthetic methods of cyclic α-aminophosphonic acids and their esters

Abstract

This review describes the most synthetic methods of cyclic α-aminophosphonic acids and their mono-or di-esters in which at least two atoms of the P−C−N system such as linkage of types C−P, C−N and P−C−N are part of a heterocyclic system.

Silver-Catalyzed, Aldehyde-Induced α-C–H Functionalization of Tetrahydroisoquinolines with Concurrent C–P Bond Formation/N-Alkylation

“…Considerable interest in organic and medicinal chemistry over the past several decades has been given to α-aminophosphonates and their derivatives because they are functional surrogates for both natural and unnatural α-amino carboxylic acids, which have broad applications owing to their unusual structural features and their association with diverse biological activities in agrochemicals and medicines, as herbicides, plant virucides, , antibacterial agents, antifungal agents, , antiviral agents, and enzyme inhibitory , and catalytic antibody activities . Among these α-aminophosphonates, C1-phosphonylated 1,2,3,4-tetrahydroisoquinolines (THIQs) as α-amino acid mimics have attracted significant attention from synthetic chemists because they are both α-aminophosphonates and alkaloids containing the potentially biologically active THIQ moiety and thus probably exhibit intriguing biological properties.…”

A convenient route to novel fluorinated 1,2,4,3-triazaphospholo[1,5-a]pyridines and pyrido[1,2-b][1,2,4,5]triazaphosphinines

“…The 1,6-diamino groups as active nucleophilic centers can be used to react with aldehyde and dialkyl phosphite under the Kabachnik-Fields reaction condition to form new 1,2,4,5-triazaphosphinine (cyclic αaminophosphonate). 25,26 Thus, compound 1 condensed with acetaldehyde in the presence of diethyl phosphite or phenyl dichlorophosphine at room temperature, followed by heating under reflux to yield two isomeric forms of pyrido[1,2-b][1,2,4,5]triazaphosphinines 16 and 19, respectively (Scheme 7). The formation of product 16 took place easily via condensation of the more chemically active N-amino group with acetaldehyde, followed by phospha-Michael addition of phosphorus atom to form the nonisolable α-aminophosphonate 15.…”

Thionation of the 2‐λ5‐Phosphaquinolin‐2‐one Scaffold with Lawesson's Reagent

“…Additionally, in many cases the thio form can be converted back to the respective oxo form through various means, a transformation which often shows a turn‐on fluorescence response [5,7–9] . Similarly, non‐aromatic aminophosphonic esters have been converted to their respective thio forms as well [10–12] . The utility of LR and the physicochemical changes it imparts upon the substrates pose the question: what other carbonyl‐like systems can be modified analogously?…”