Yuri G. Gololobov

Unusual transformations of ethyl-2-cyanoacrylate in reactions with trivalent phosphorus compounds

Abstract Interaction of ethyl-2-cyanoacrylate 1 with trivalent phosphorus compounds can cause not only polymerization of 1 , but under established conditions it affords, depending on the structure of the latter, betaines 3 , spirophosphoranes 5 , i.e. phosphorylated at the carbonyl oxygen esters of 2-cyanopropionic acid or 2-cyano-3-phosphoranylpropionates 9 .

ZWITTERIONIC SPECIES FROM TRIISOPROPYLPHOSPHINE AND 2-CYANOACRYLATES: SYNTHESIS, STRUCTURE AND PROPERTIES

Abstract Triisopropylphosphine reacts with 2-cyanoacrylates with formation of the P-zwitterionic species 2a and 2b. The reaction of 2b with trimethylsilyltriflate, in the presence of traces of water, leads to the phosphonium triflate 3. 2b is alkylated at the carbon atom with methyl iodide with formation of the phosphonium iodide 4. The initially formed adducts of the zwitterionic species 2a and 2b with tosyl azide and with tosyl isocyanate are thermodynamically unstable. In the first case, the final products of the reaction are tosyl iminotriisopropylphosphine imide 6 and 2-cyanoacrylate polymers. In the second case, the reaction leads to the zwitterionic product 8, and, in the presence of traces of water, to the molecular complexes 9a and 9b. The reaction of the zwitterionic species 2a and 2b with methylisocyanate proceeds in an unusual way, resulting in the formation of the zwitterionic species 12a and 12b, as a result of the insertion of methylisocyanate into the C[sbnd]C bond of the starting zwitteri...

Peculiarities of structure and properties of phosphorus-containing cations with two intramolecular donor-acceptor bonds N→P. Synthesis of the first 5-coordinated P-cation with PN bond

cations 1a,b display dual reactivity, and they interact both with electrophilic and nucleophilic reagents. Reaction with chloramine B or benzenesulphonylazide leads to the formation of first representative of 5-coordinated P-cations with Pue5f8N bond.

P…N Interaction and its Effect on the Structure and Properties of Phosphorylated α-Aminoketones Derivatives

Abstract Reactions of α-aminoketones with P-chlorides in a basic medium are reported. Methods for the synthesis of Δ4-1,3,2-oxazahospholines and s-amino of phosphorus from N to O and enamin-imine isomerization are discussed for the phosphorylated aminoketones. Nucleophylic and electrophylic reactivity of cationes XV and XVI was studied.

Synthesis, Properties, and Atropisomerism of Arylcarbamates with a Phosphonium Group

The reactions of the zwitterionic species 1 with ortho -substituted aryl isocyanates proceed in an unusual way, resulting in the formation of the P-containing carbamates 3. In the latter (except for X=F) the CH 2 P protons are anisochronous and give rise to an AB pattern at the corresponding temperatures (1H{31P}). When the temperature is increased, the AB pattern coalesces to a singlet. The j G c # values, together with all pertinent data, are listed.

P-Zwitterions from Trialkylphosphines and 2-Cyanoacrylates

The recent developments in the chemistry of P-zwitterions 2 are discussed. They include unusual reactions of 2 with HgCl2, ArN3, TosNCO and Alk(Ar)NCX (X=O,S). The insertion reactions of alkyiso(thio)cyanates into C-C bond are considered. A novel type of the intramolecular electrophilic rearrangements is described.

Donor-Acceptor N → P Interaction and its Effect on the Phosphorylation of α-Aminoketones

Abstract Aminovinylphosphites of Z-configuration R2″PO-CR═CH-NR2 are formed in the reaction of α-aminoketones RCOCH2NR2 and chlorophosphites with the use of triethylamine as a base. The high stereoselectivity of this process is due to the preliminary coordination of phosphorus chloride to the amino group of the substrate and the following intramolecular rearrangement in the complex with the simultaneous evolution of the salt of hydrogen chloride with triethylamine. A thermodynamic study of the complex formation between reactants in the first stage of the above mentioned process supports this idea.

Unusual Transformations of 2-Cyanoacrylates in Reactions with Trivalent Phosphorus Compounds

Abstract Cyanoacrylates 1 have existed for 40 years, but up till 1 only polymerization processes, effected by various nucleophiles, including trivalent phosphorus compounds, have been known. We have shown that under established conditions 1 (aR=Me, b R=Et) reacts with trivalent phosphorus compounds not only via the anionic polymerization pathway, but depending on the structure, it forms stable adducts2,4 or 5.

FORMATION OF PHOSPHORUS-CONTAINING SPIRO CATIONS, STABILIZED BY THREE-CENTERED N → P ← N BOND, IN THE SERIES OF PHOSPHORYLATED α-AMINOKETONES

Abstract Spiro cation stabilized by three-centered bond N → P ← N, is formed in the reaction of phosphorus trichloride with two molecules of t-BuCOCH2NMe2. According to X-ray analysis data, the structure of the compound obtained is close to a trigonal bipyramid with nitrogen atoms in axial positions (P-N 2.05 A), and two oxygen atoms and lone electron pair of phosphorus in equatorial positions.

Novel Rearrangements and Heterocyclisation of P-Imides

Abstract The preliminary introduction of electron accepting dichlorophosphine group at nitrogen atom of N-monosub-stituted α-aminoketones or α-aminocarbon acid esters increases the mobility of the α-carbon hydrogen atom so, that the intermolecular O-phosphorylation is enabled.1