Double Kabachnik-Fields

Double Kabachnik-Fields condensations were also elaborated applying two equivalents of the formaldehyde and the >P(0)H species to one equivalent of the primary amine (Scheme 21) [75-77]. 

E. Balint, E. Fazekas, G. Pinter, A. Szollosy, T. Holczbauer, M. Czugler, L. Drahos, T. Kortvelyesi, G. Keglevich, Synthesis and utilization of the bis(>P(0)CH2)amine derivatives obtained by the double Kabachnik-Fields reaction with cyclohexylamine quantum chemical and X-ray study of the related bidentate chelate platinum complexes, Curr. Org. Chem. 16 (2012) 547-554. 

Furthermore, the same group accomplished the double Kabachnik-Fields condensation reaction using two equivalents of formaldehyde and the >P(0)H species to one equivalent of the primary amine in the synthesis in good yields of a series of bis(phosphonomethyl)amines and related derivatives (64), following a MW-assisted solvent-less procedure (Scheme 30). The investigators then extended the double Kabachnik-Fields reaction to the synthesis of bis(phosphinoxidomethyl)amines (65), and herein the use of acetonitrile as solvent was required (Scheme 31). The bis(phosphinoylmethyl)amines (65) are useful precursors of bidentate... 

Scheme 30 Synthesis of bis(phosphonomethyl)amines and their derivatives by a double Kabachnik-Fields reaction.

Scheme 31 Synthesis of bis(phosphinoxidomethyl)amines by double Kabachnik-Fields reactions.

The Keglevich group has continued to deal with environmentally friendly and P-heterocyclic chemistry. The solid liquid phase alkylation of P=0-functionalised CH acidic compounds was accomplished under phase transfer catalytic and microwave (MW) conditions." a-Hydroxy-benzylphosphine oxides were synthesized by the addition of diphenylphosphine oxide to the carbonyl group of substituted benzaldehydes under MW conditions." The double Kabachnik-Fields (phospha-Mannich) reaction was utilized in the preparation of bis(phosphinoxidomethyl)amines. The Diels Alder cycloadditions of 1,2-dihydrophosphinine oxides and subsequent... 

The double Kabachnik-Fields (phospha-Mannich) reaction of primary amines, two equivalents of paraformaldehyde and the same amount of diphenylphosphine oxide gave bis(diphenylphosphinoylmethyl)amines that were precursors of bidentate P-ligands after double deojq genation... 

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