ChemInform Abstract: Reactions of 2‐Chloro‐2‐methylpropaneimidoyl Chlorides with Trialkyl Phosphites.

Sinitsa, A. D.; Maidanovich, N. K.; Onys’ko, P. P.; Shurubura, A. K.

doi:10.1002/chin.199024218

Cited by 2 publications

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“…Electron-acceptor substituents facilitate proton transfer, and, other conditions being equal, an isomer that has the strongest electronacceptor substituents at the sp 3 -carbon atom, is the most thermodynamically favorable [2,7,21]. Hence, proton transfer in (N-methyltrifluoroacetimidoyl)-phosphonate in the presence of Et 3 N takes place at 20oC (Scheme 4), and imidoylphosphonate XXVI with the weaker electron-acceptor Me 2 CCl group at the imidoyl carbon atom is stable under analogous, as well as more rigid conditions [22]. Contrary to easily isomerized N-benzimidoylphosphonates VII, N-benzylimine XXVII containing no phosphorus at the imine carbon atom is insusceptible to proton transfer even on heating in the presence of nitrogenous bases (DBU, Dabco), even though N-benzylidene isomer XXVIII is evidently thermodynamically more favorable.…”

Section: ääääääääääämentioning

confidence: 96%

Sigmatropic isomerizations in azaallyl systems: XXI. Alkanimidoylphosphonates and their prototropic and phosphorotropic isomers

et al. 2004

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Synthetic procedures for alkanimidoylphosphoryl derivatives with a-hydrogen atoms in the N-alkyl radical are developed. Data on the effect of substituents at the carbon and phosphorus atoms on the facility of prototropic transitions in the C=N3C triad are summarized. The most facile proton transfer occurs in the N-benzyl derivatives, and the prototropic isomer is the more stable, the stronger the electron-acceptor power of the substituent at the sp 3 -carbon atom of the azaallyl triad. The proton transfer in N-(a-phenethyl)-trifluoroacetimidoylphosphonates proceeds selectively, which allows preparation of enantiomerically enriched derivatives of a-aminotrifluoroethylphosphonic acid. A specific effect of substituents at the phosphorus atom on the prototropism attendant on phosphorylation of imidoyl chlorides is demonstrated.The methylene3azomethine system is one of the least labile prototropic triads. An electron-acceptor phosphorus-containing group at the sp 2 -carbon atom of the C=N3CH triad much increases the lability of the proton and thus renders such compounds labile prototropic systems [2]. Proton transfer in phosphorylated azaallyl derivatives is synthetically attractive, providing a way to converting imidoylphosphonic to biologically important a-aminophosphoryl compounds [3,4]. The 1,3-phosphorotropic isomerization we discovered in the C=N3CH triad [5, 6] permits to perform interconversions of different a-aminophosphoryl derivatives.In the present work we considered the effect of alkyl groups at the sp 2 -and sp 3 -carbon atoms of a phosphorylated azaallyl triad on the facility of 1,3-prototropic and phosphorotropic transitions, as well ÄÄÄÄÄÄÄÄÄÄÄÄ as the effect of substituents on the phosphorus atom on the prototropism attendant on phosphorylation of imidoyl chlorides.As one of the synthetic approaches to imidoylphosphoryl compounds, we for the first time used the azaWittig reaction with acetylphosphonate I as the carbonyl component. It was found that imidoylphosphonate III formed by the reaction of oxophosphonate I with phosphazo compound II undergoes irreversible isomerization to a-phosphorylated benzalimine IV under the reaction conditions. The preference for the imine3imine isomerization over the imine3enamine rearrangement III 6 V (Scheme 1) is assignable to the possibility of effective conjugation of the C=N bond with the phenyl ring in N-benzylidene structure IV, which makes this structure favorable [2,7].

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Section: ääääääääääämentioning

confidence: 96%

Sigmatropic isomerizations in azaallyl systems: XXI. Alkanimidoylphosphonates and their prototropic and phosphorotropic isomers

et al. 2004

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“…Depending on the mobility of -hydrogen atom in the Nalkyl group, phosphorylation of imidoyl chlorides 13 leads to imidoyl phosphonates 14 or is accompanied by elimination of hydrogen chloride, to afford synthetically promising phosphorylated azadienes 15 (Scheme 4) [7].…”

Section: Nucleophilic Phosphorylation Of N-alkyl- N-h and N-trimethmentioning

confidence: 99%

“…Reactivity increases with the growth in electronwithdrawing properties of the haloalkyl group, and the reaction route is altered: N-H (4) and N-trimethylsilyl imines 5,6 react exothermally with trialkylphosphites or triphenylphosphine to give iminophosphorane (7,8), products of Nphosphorylation (Scheme 2) [3,4].…”

Section: Nucleophilic Phosphorylation Of N-alkyl- N-h and N-trimethmentioning

confidence: 99%

Phosphorylation of α-Haloimines: P-C vs. P-N Bond Formation

Onys’ko¹,

Rassukana²,

Sinitsa

2008

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The chemoselectivity of reactions between -haloimines -compounds containing a Hal-C-C=N-skeleton -and nucleophilic phosphorus derivatives are discussed systematically. The synthetic potentialities, as well as possible mechanistic pathways of this currently developing field of organophosphorus chemistry are considered. Phosphorylation of the -haloimines leads mainly to C-or N-phosphorylated compounds as the final products, the selectivity being dependent on the type of halogen, substituents at the imine carbon and nitrogen atoms, and on the nature of phosphorus reagent. The main factors controlling regio-and stereoselectivity are elucidated. A series of novel theoretically and preparatively important transformations have also been illustrated; i.e., new diad rearrangements involving the N C and C N transfer of a sulfonyl or a phosphoryl group, the unusual acylation of the electrophilic imine carbon atom by tervalent phosphorus isocyanates, and others. Variety of transformations is connected with the possible participation of C=N bond, halogen atoms or N-substituents, in reactions involving the Hal-C-C=N-arrangement. The use of haloimines as versatile building blocks for synthesis of practically promising functionalized aminophosphonates, bisphosphonates, and phosphorus analogs of dehydro aminoacids, etc., is demonstrated.

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ChemInform Abstract: Reactions of 2‐Chloro‐2‐methylpropaneimidoyl Chlorides with Trialkyl Phosphites.

Abstract: ChemInform Abstract Reaction of the 2-chloro-2-methylpropaneimidoyl chlorides (Ia) and (Ib) with triethyl phosphite (II) gives the imidoyl phosphonates (IIIa) and (IIIb), whereas the dehydrochlorination product (IV) is obtained from (Ic) and (II).

Cited by 2 publications

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Sigmatropic isomerizations in azaallyl systems: XXI. Alkanimidoylphosphonates and their prototropic and phosphorotropic isomers

Sigmatropic isomerizations in azaallyl systems: XXI. Alkanimidoylphosphonates and their prototropic and phosphorotropic isomers

Phosphorylation of α-Haloimines: P-C vs. P-N Bond Formation

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ChemInform Abstract: Reactions of 2‐Chloro‐2‐methylpropaneimidoyl Chlorides with Trialkyl Phosphites.

Abstract: ChemInform Abstract Reaction of the 2-chloro-2-methylpropaneimidoyl chlorides (Ia) and (Ib) with triethyl phosphite (II) gives the imidoyl phosphonates (IIIa) and (IIIb), whereas the dehydrochlorination product (IV) is obtained from (Ic) and (II).

Cited by 2 publications

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Sigmatropic isomerizations in azaallyl systems: XXI. Alkanimidoylphosphonates and their prototropic and phosphorotropic isomers

Sigmatropic isomerizations in azaallyl systems: XXI. Alkanimidoylphosphonates and their prototropic and phosphorotropic isomers

Phosphorylation of &#945;-Haloimines: P-C vs. P-N Bond Formation

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Phosphorylation of α-Haloimines: P-C vs. P-N Bond Formation