Preparation and crystal structure of 1,1-tetramethylethylenedioxy-3,4-diphenyl-6-trichloromethyl-2,5,7,1-trioxaphosphabicyclo[2.2.1<Superscript>1,4</Superscript>]heptane and 2-(1-hydroxy-2,2,2-trichloroethoxy)-4,4,5,5-tetramethyl- 2-oxo-1,3,2-dioxaphospholane

The state of the art of chloral applications in the chemistry of tricoordinate phosphorus derivatives has been analyzed. The highly stereoselective reaction of 4,4,5,5-tetramethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane with chloral has been shown to afford a caged phosphorane with the phosphorus–carbon bond, 1,1-tetramethylethylenedioxy-3,4-diphenyl-6-trichloromethyl-2,5,7,1-trioxaphosphabicyclo- [2.2.1^1,4]heptane. Structure of the phosphorane and its hydrolysis product, 2-(1-hydroxy-2,2,2-trichloroethoxy)- 4,4,5,5-tetramethyl-2-oxo-1,3,2-dioxaphospholane, has been elucidated by X-ray diffraction analysis.     

Reaction of arylenedioxytrihalophosphoranes with acetylenes 12. Alkylacetylenes in the reaction with 2,2,2-trihalobenzo-1,3,2-dioxaphospholes

A reaction of 2,2,2-trihalobenzo-1,3,2-dioxaphospholes with terminal alkylacetylenes proceeds under mild conditions (～20 °C) and leads to the formation of 4-alkylbenzo[e]-1,2-oxaphosphinine 2-oxide derivatives. The presence of aliphatic substituents in acetylene decreases (as compared to their aromatic counterparts described earlier) regioselectivity of halogenation of benzo fragment in 4-alkylbenzo[e]-1,2-oxaphosphinines: besides predominant 4-alkyl-2,6-dihalobenzo[e]-1,2-oxaphosphinines, minor 2,7- and 2,8-dihalo-substituted 4-alkylbenzo[e]-1,2-oxaphosphinines are formed. An unusual thermal isomerization of 4-alkyl-2-fluorobenzo[e]-1,2-oxaphosphinines to 4-alkylidene-2-fluoro-3,4-dihydrobenzo[e]-1,2-oxaphosphinines was discovered. Molecular and supramolecular structures of some 4-alkylbenzo[e]-1,2-oxaphosphinines were studied by X-ray diffraction analysis.     

New derivatives of 4,4,5,5-tetramethyl-4,5-dihydro-1-H-imidazol-1-oxyl 3-oxide as monomers for polyradicals with special magnetic properties

The preparation of new derivatives of 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxyl 3-oxide as monomers for purely organic polymers with special magnetic properties is described. 3,5-Diethynylbenzaldehyde and 3,5-bis(trimethylsilylethynyl)benzaldehyde were converted to the corresponding 1,3-dihydroxy-4,4,5,5-tetramethylimidazolidine derivatives which were oxidized to stable nitronyl nitroxide radicals.     

Reaction of 2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole-5-carbonylchloride with phenylacetylene: predominant formation of 2-(2-chloro-2-phenylethenyl)-2,2-dichlorobenzo[d]-1,3,2-dioxaphosphole-5-carbonylchloride

The reaction of 2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole-5-carbonylchloride with phenylacetylene in benzene (80 °C) afforded 2-(2-chloro-2-phenylethenyl)-2,2-dichlorobenzo[d]-1,3,2-dioxaphosphole-5-carbonylchloride (yield >95%) as a result of the electrophilic cis-addition of the phosphorus(v) derivative at the triple bond of acetylene with retention of coordination of the P atom. Hydrolysis of this compound affords predominantly 2-hydroxy-5-(hydroxycarbonyl)phenyl (2-chloro-2-phenylethenyl)phosphonate. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 377–379, February, 2006.     

Crystallography and magnetism of radicals with hindered hydroxyl groups: 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl and 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl

Radicals form networks of OH...ON and OH...Me(nitroxide) interactions. In 2, a frustrated network forms with insufficient N-O units to form extended chain interactions. The magnetism of 1 fits a 1-D Heisenberg model with J/k=-25 J mol(-1), while 2 shows more complex exchange behaviour consistent with its disordered crystal lattice.     

Electronic structure of the organic half-metallic magnet: 2-(5-pyrimidinyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-3-oxoimidazol-1-oxyl

An accurate full-potential density-functional method is used to study the magnetic and half-metallic properties in the pure organic materials: 2-(5-pyrimidinyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-3-oxoimidazol-1-oxyl. The total and partial density of states and atomic spin magnetic moments are calculated and discussed. It is found that the unpaired electrons in this compound are localized in a molecular orbital constituted primarily of π^*(NO) orbital, and the main contribution of the spin magnetic moment comes from the NO free radicals. It is predicted that this compound is half-metallic magnet. It is also found that there exists ferromagnetic intermolecular interaction in the compound.     

Reaction of sulfene with n,N-disubstituted α-aminomethyleneketones vi. Synthesis of n,n-disubstituted 4-amino-3,4-dihydro-6-phenyl-1,2-oxathiin 2,2-dioxides and of 4-methylphenylamino-3,4-dihydro-5,6-polymethylen-1,2-oxathiin 2,2-dioxides

The title compounds were obtained by cycloaddition of sulfene to N,N-disubstituted 3-amino-1-phenyl-2-propen-1-ones and to 2-metbylphenylaminomethylenecycloalkanones, respectively. Steric and electronic aspects of these reactions, as well as the failure of cycloaddition in the case of N,N-disubstituted 4-arnino-3-buten-2-ones, are also discussed.     

Reactions of trihalo(phenylenedioxy)phosphoranes with arylacetylenes: IX. Reaction of 2,2,2-trichloro-1,3,2λ5-benzodioxaphosphole with 1-Iodo-2-phenylethyne

According to NMR data, the reaction of 2,2,2-trichloro-1,3,2λ⁵-benzodioxaphosphole with 1-iodo-2-phenylethyne leads to formation of 2,6-and 2,8-dichloro-3-iodo-4-phenyl-1,2λ⁵-benzoxaphosphinine 2-oxides which undergo partial hydrodeiodination to 2,6-and 2,8-dichloro-4-phenyl-1,2λ⁵-benzoxaphosphinine 2-oxides, respectively.     

4-Phenylsulfenyl- and 4-Phenylselenenyl-2,5-dihydro-1,2-oxaphosphole-2-oxides by the Reaction of 1,2-Alkadienephosphonic Amidoesters with Sulphenyl- and Selenenylbromides

The reactivity of 1,2-alkadienephosphonic amidoesters towards sulphenyl- and seleneneylbromides has been investigated.     

Reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with phenylacetylene. ipso-Substitution of the tert-butyl group

The reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with phenylacetylene follows the mechanism of ipso-substitution of the tert-butyl group that is in para-position relative to the endocyclic O atom of the heterocycle, predominantly yielding 8-(tert-butyl)-2,6-dichloro-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine (NMR data). The structure of its hydrolysis product, 8-(tert-butyl)-6-chloro-2-hydroxy-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine, was proved by X-ray diffraction analysis.     

Reaction of singlet oxygen with trans-cyclooctene. Evidence for a 1,2-dioxetane intermediate.

Evidence is presented that the reaction of ¹O₂ with trans-cyclooctene yields an unstable trans-fused bicyclic dioxetane as a significant product.     

Simple reagent for the synthesis of oligonucleotides labeled with 3,3,3′,3′-tetramethyl-2,2′-indodicarbocyanine

Synthesis of a phosphoramidite reagent for the preparation of oligonucleotides labeled at the 5′-end with a fluorescent dye, 3,3,3′,3′-tetramethyl-2,2′-indodicarbocyanine, is described. The efficiency of this reagent is confirmed by the synthesis of several labeled oligonucleotides. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 154–158, January, 2006.     

Reaction of trihalo(phenylenedioxy)phosphoranes with acetylenes: X. specific features of the reactions of substituted 2,2,2-trichloro-1,3,2λ5-benzodioxaphospholes with 3-chloro(bromo, iodo)propynes

It was shown for the first time that 3-chloro-, 3-bromo-, and 3-iodopropynes can react with 2,2,2-trichloro-, 2,2,2-trichloro-5-methyl-, and 5,6-dibromo-2,2,2-trichloro-1,3,2λ⁵-benzodioxaphospholes to give derivatives of 4-(halomethyl)-2-chloro-2H-1,2λ⁵-benzoxaphosphinin-2-ones. The reaction involves nonselective chlorination of the phenylene substituent in different positions, and the resulting isomer ratio is temperature-dependent. In the reactions of 3-bromo-and 3-iodopropynes with 2,2,2-trichloro-1,3,2λ⁵-benzo-dioxaphosphole, a side process takes place, viz. nucleophilic substitution of bromine and iodine with chlorine. The structure of some of the prepared 4-(chloromethyl)-1,2-benzoxaphosphinines was studied by means of X-ray diffraction.     

Regiochemistry of the Reaction of Ethoxyacetylene with 2,2,2-Trichlorobenzo[d]-1,3,2λ5-dioxaphosphole,as Studied by Dynamic 13C and 31P NMR Spectroscopy

Russian Journal of General Chemistry -