Microwave-Assisted Kabachnik–Fields Reaction with Amino Alcohols as the Amine Component

Abstract

In this paper, the microwave (MW)-assisted catalyst-free and mostly solvent-free Kabachnik–Fields reaction of amino alcohols, paraformaldehyde, and various >P(O)H reagents (dialkyl phosphites, ethyl phenyl-H-phosphinate, and secondary phosphine oxides) is reported. The synthesis of N-2-hydroxyethyl-αaminophosphonate derivatives was optimized in respect of the temperature, the reaction time, and the molar ratio of the starting materials. A few by-products were also identified. N,NBis(phosphinoylmethyl)amines containing a hydroxyethyl group were also prepared by the double Kabachnik–Fields reaction of ethanolamine with an excess of paraformaldehyde and secondary phosphine oxides. The crystal structure of a 2-hydroxyethyl-α-aminophosphine oxide and a bis(phosphinoylmethyl)ethanolamine was studied by X-ray analysis.

Recent Advances on Fabrication of Polymeric Composites Based on Multicomponent Reactions for Bioimaging and Environmental Pollutant Removal

“…[ 112 ] The carbonyl group is bonded with an amine to form imine, followed by the PH bond on the homophosphate molecule by double bond addition (Pudovik reaction) to form amino phosphonate, which is executed under mild environmental system and water is the only by‐product. [ 113,114 ] KF reaction can be employed for two polymer linkage and polycondensation or end chain functionalization. In addition, surface functionalization of inorganic substrate materials can also be accomplished by a one‐step KF reaction.…”

An Overview of Microwave‐Assisted Kabachnik‐Fields Reactions

“…In this context, Kabachnic and co-workers in 2005 successfully established the possibility of incorporating α-aminophosphonate into natural porphyrins through KF reaction, where condensation of natural porphyrins with tert-butyl amine and diethylphosphite (1 : 1 : 3) in DCM was accomplished in good to excellent yields by irradiating with MW radiations (Scheme 52). 51 Clercq et al in one of their previous works, reported a synthetic strategy for obtaining quinoline-based α-aminophoshphonates.52 However, the desired product was furnished in poor yield (< 20 %). In 2009, Juribasic and Tusek-bozic have successfully employed MW radiations in a three-component one pot reaction between quinoline-3-carboxaldehyde and aniline as well as 3-aminoquinoline and benzaldehyde with diethylphosphite.…”

Supramolecular Diversity of Oxabicyclo[2.2.2]octenes Formed between Substituted 2H-Pyran-2-ones and Vinyl-Moiety-Containing Dienophiles

“…Additionally, a single crystal of cyclohexadiene product 4a was also prepared; however, in contrast to the high-pressure conditions appropriate for the preparation of 3, here thermal activation with microwaves was necessary. Microwave irradiation as a way to facilitate organic reactions has during the last decades found some surprisingly widespread applications, as recently vividly described by Kappe [48], including acceleration of Diels-Alder reactions [2,49], Kabachnik-Fields reaction [50] and many others. It is worth noting that product endo-3e was isolated by precipitation upon slow evaporation of the volatile components from the mother liquor (which remained after the precipitation of exo-3e and its removal by vacuum filtration) containing an appreciable amount of the starting dienophile 6a (which was initially applied in a large excess, also as a co-solvent, in molar ratio 1e:6a = 1:27).…”