Treatment of diazoalkanes with unsaturated compounds. No. 5. Catalytic cyclopropanation of unsaturated hydrocarbons with diazoethane

Conclusions The preparative catalytic cyclopropanation of unsaturated hydrocarbons with diazoethane has been achieved for the first time. Addition of the ethylidene fragment to the C=C double bond occurs in a nonstereoselective manner and leads to the formation of the corresponding methylcyclopropanes in 55–70% total yields. In the presence of CuCl, all double bonds of unsaturated hydrocarbons are cyclopropanated with equal facility, whereas in the presence of (PhCN)₂PdCl₂, preferential regioselective cyclopropanation of strained endocyclic and terminal double bonds is observed, just as was true in the case of reactions with diazomethane.For Communication No. 4, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1338–1343, June, 1987.     

Geminal systems. 16. Reactions of N-chloro-N-alkoxy-N-alkylamines with amines

Conclusions The reactions of N-chloro-N-alkoxy-N-tert-alkylamines with amines are characterized by nucleophilic substitution at the nitrogen atom with formation of the corresponding N-alkoxyhydrazines which are stable in the case of ethyleneimine and pyridine; give diazenes as in the case of MeNH₂, EtNH₂, and Me₂ or yield products of further transformations as in the case of NH₃, Me₂NH, and MeO(Me)NH. Nucleophilic substitution is repressed in the reaction with Et₂NH and Et₃ N by one-electron reduction with the formation of azoxy compounds.For Communication 15, see previous article [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2327–2334, October, 1981.     

Study of reaction of sulfur halides with unsaturated. Compounds. 24. Reaction of sulfur monochloride with adamantylidene-adamantane

Conclusions In the reaction of adamantylideneadamantane with S₂Cl₂ at an equimolar ratio of the reagents, 2,2-epithio-2-(2-adamantyl)adamantane and 4-chloro-2,2-epithio-2-(2-adamantyl)-adamantane are formed, while with an excess of S₂Cl₂, the products are 4e-chloro- and 4e,4e-dichloroadamantylideneadamantane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 617–620, March.Article 23, see [1].     

Reactions of perfluoronitriles. III. Interactions with diphenylphosphine

Reaction of perfluoro-n-octanonitrile with diphenylphosphine gave two products: a primary adduct, C₇F₁₅C(NH)P(C₆H₅)₂, and the reduced adduct, C₇F₁₅CH(NH₂)P(C₆H₅)₂. Presence of water prevented the formation of the reduced compound; the latter was not produced by reduction of the primary adduct. Operative mechanisms are postulated; infrared and mass spectra are discussed.     

Boron-nitrogen compounds. 94. Reactions of Dimethylaminoboranes with Pyrazole

Depending on the reaction conditions, the interaction of tris(dimethylamino)borane with pyrazole (Hpz) yields (CH₃)₂HNBpz₃ (III) or the pyrazaboles B₂pz₄[N(CH₃)₂]₂ (IV, cis and trans isomer), B₂pz₅N(CH₃)₂ (Va), or B₂pz₆. There is evidence that the reactions proceed via the extremely short-lived [(CH₃)₂N]₂ Bpz and, in particular, monomeric (CH₃)₂NBpz₂; the latter species can be identified in the mass spectrometer. In the system bis(dimethylamino)phenylborane/pyrazole the species (CH₃)₂HNB(C₆H₅)pz₂ and the pyrazabole B₂pz₃(C₆H₅)₂N(CH₃)₂ (VII, cis and trans isomer) were obtained. Also, some data on the pyrazabole B₂pz₂(C₆H₅)₂[N(CH₃)₂]₂ were collected although the compound could not be isolated in the pure state. The existence of the monomer (CH₃)₂NB(C₆H₅)pz could be established.     

Polymer-Bromine Interactions. I. Interactions with Polyacrylonitrile

The present paper deals with the interactions of bromine with poly-acrylonitrile (PAN). Kinetics and equilibria of the sorption of Br₂ on PAN were studied at a concentration range of 0.01–0.1 mol/L and a temperature range of 25–40°C. Two kinds of sorption were found: a “reversible” sorption removable by water and an “irreversible” sorption removable by aqueous ammonia solutions. The irreversibly sorbed bromine is presumably linked by charge transfer to the nitrile groups of the PAN, as evidenced by UV spectra. The irreversible sorption follows the reversible sorption and is slower. Partition coefficients obtained from the linear Freundlich isotherms increased with temperature and, at 40°C, the values obtained were 97, 65, and 32 L/kg for the total, irreversible, and reversible sorptions, respectively. At 25°C the chemical potential, enthalpy, and change in entropy for the irreversible sorption were ?2.0 kcal/mol, 9.4 kcal/mol, and 38 cal·mol^?1·K^?1. Effects of a 6-day Br₂ treatment and ammonia rinse were: decrease in dry T _g from 74.5 to 61°C and in water from 38 to 35°C; no significant decrease in M _W ; decrease in tensile strength measured after the bromine stage, and improvement after ammonia stage; increased swollen dimensions from 57% in water to 75%; and stabilization of swollen dimensions upon drying. The results support the existence of two phases in the less ordered regions of PAN.     

Reactions of perfluoronitriles. II. Interactions with phenylphosphine

Treatment of perfluoro-n-octanonitrile with phenylphosphine gave tetraphenyltetraphosphine and a spectrum of reduction and interaction products. Fifteen compounds were identified. The imine, (R_fC₇F₁₅) R_fCHNH, and the amine, R_fCH₂NH₂, were the primary reduction products. Secondary phosphorus-free products, some formed following ammonia evolution, were the following: R_fCHNCH₂R_f, R_fCH₂CH(NH₂)R_f, R_fC(NH)NCR_f(NH₂), R_fCH₂NHCR_f(NH), (R_fCN)₃, R_fCHNCR_fNCR_f(NH), R_fCH₂NCR_fNHCH₂R_f, and R_fCH₂NCR_fNHCR_f(NH). Only three phosphorus-containing materials were definitely identified: R_fCH(NH₂)P(C₆H₅)H, R_fCH[P(C₆H₅)H]NCHR_f, and R_fC(NH)P(C₆H₅)CR_f(NH). Depending on reaction conditions, specific phosphorus-containing compounds could be preferentially produced. All the structure assignments are based solely on mass spectral breakdown patterns, since pure compounds were not isolated.     

Pyridazines. LXX. Reactions of azidoazolopyridazines with unsaturated compounds

Cycloaddition reactions of azidoazolopyridazines with unsaturated esters, cyclic enol ethers, styrene, 2-vinyl-pyridine, bicyclo[2.2.1]heptene, dicyclopentadiene and dehydrobenzene were investigated. The reaction proceed via the intermediate Δ² -1,2,3-triazolines which were in most cases termolabile and decomposed further to give the final products which were enamines, imines of fused aziridines.     

Modification of Lignins. III. Reaction of Lignosulfonates with Chlorophosphazenes

Abstract

A new trend in flame- and heat-resistant polymers is the modification of organic by-products such as lignins. Here we continue a discussion of lignin modification; in particular, the reaction of lignosulfonates with chlorophosphazenes. The reactivity of Borregaard-type lignosulfonates toward chlorophosphazenes was studied. The properties of the products obtained, especially their flame and heat resistance, as well as SEM data, were investigated.     

Correlation of the prigogine-flory theory with isothermal compressibility data. I. Systems with quasi-spherical molecules

The isothermal compressibilities K_T for cyclohexane + benzene, cyclohexane + toluene and benzene + toluene systems at 25, 35, 45 and 60°C have been used to test the Prigogine-Flory theory using Van der Waals and Lennard-Jones energy potentials. Flory's energy parameter X ₁₂ was calculated for these systems at the four temperatures. From X ₁₂ for the equimolar mixture, the following excess functions were calculated: (?V^E/?_p)_T which is related to K _T ^E , the heat of mixing H ^E , and the excess volume V ^E . The theory and any of the two potentials give (?V^E/?_p)_T which fit the experimental data, but H ^E and V ^E , calculated using the same X ₁₂ parameter, depart appreciably from the experimental data even though they agree in sign and have the essential features of the excess functions. The departure is apparent in both magnitude (in particular for the cyclohexane + benzene, and cyclohexane + toluene systems) and in the temperature dependence. The conclusion is that the X ₁₂ parameter does not predict the thermodynamic properties of these systems and the Lennard-Jones potential, involving a more complicated expression, does not contribute any improvement over the Van der Waals potential.     

N-haloamidines. VI. Reaction of n-chloro-n'-benzenesulfonylbenzamidines with enamines

The reaction between N-chloro-N'-benzenesulfonylbenzamidines and ß,ß-disubstituted enamines affords N-(benzenesulfonyl)-N'- [(2-chloro-2-substituted-l-amino)-propyl]-benzamidines. When both ß-substi tuents are methyl groups the open chain adducts have been isolated and characterized; whereas, when one of the two substituents is a phenyl group, they have been characterized only by PMR because of the easy cyclization to 1-benzenesulfonyl-4, 5-dihydroimidazoles.     

The reaction of triphenylphosphine with arylbromonitromethanes. Formation of arylnitriloxides.

Formation of furoxans and δ²-isoxazolines confirms that arylnitriloxides are intermediates in the reaction of arylbromonitromethanes with triphenylphosphine.     

Metal complexes with macrocyclic ligands. XIII. The complexation of Cu2+ with triazacycloalkanes

The potentiometric study of the complexation of Cu²⁺ with 1,4,7-triazacyclononane ( 1 ), 1,4,8-triazacyclodecane ( 2 ) 1,5,9-triazacyclododecane ( 3 ) has shown that CuL, CuL₂ and (CuLOH)₂ are the main species present in solution. Their stabilities (Table 1) and their absorption spectra (Table 2) indicate facial coordination of the cyclic triamines in a distorted octahedral geometry. The formation and dissociation kinetics have been measured by stopped-flow techniques. The formation in acetate buffer can be described by the reaction of Cu²⁺ and CuAcO⁺ with the monoprotonated species of the ligand. The bimolecular rate constants for these complexations (Table 3) decrease when the ring size increases. In contrast the dissociation induced by acid is only little affected by the ring size. Thus for these complexes the rate of formation and not that of the dissociation determines the overall stability.     

Reactions of nitrile oxides with nitrogen oxides. 1. Reactions with nitrogen tetroxide

We have studied the reaction of nitrile oxides with nitrogen tetroxide. It was shown that the reaction is selective: acetonitrile oxide yields ethylnitrolic acid, -oximinophenylacetonitrile oxide gives a mixture of isomers of phenylnitrofuroxan, and aromatic nitrile oxides give aryltrinitromethanes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1620–1622, July, 1990.     

Reaction of unsaturated compounds with diazoalkanes. Communication 3. Cyclopropanation of cyclooctatetraene with diazomethane

Conclusions The cyclopropanation of the double bonds in cyclooctatetraene by diazomethane in the presence of cuprous chloride is nonregioselective and leads to the formation of the corresponding mono-, di-, tri-, and tetracyclopropanation products with yields determined by the amount of added diazomethane. The obtained bis-, tris-, and tetrakishomocyclooctatetraenes are characterized by a preference for the isomers with the exo orientation of the cyclopropane fragments.For Communication 2, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 77–84, January, 1986.     

Polymerization of hexamethylcyclotrisiloxane with a biscatecholsiliconate. I. Nature of polymerization

Polymerization behavior of hexamethylcyclotrisiloxane (D₃) in toluene solution with the use of benzyltrimethylammonium bis(o-p;henylenedioxy)phenylsiliconate as a catalyst, dimethyl sulfoxide as promoter, and adventitious moisture as initiator was investigated. The polymerization system gives a linear difunctional polymer, HO(Me₂SiO)_xH, with a molecular weight which is inversely proportional to the amount of water reacted rather than to the amount of catalyst employed. The polymerization in the presence of H₂O gives rise to molecular weight distributions very close to Poisson distributions. The normalized experimental GPC curve agrees very well with the theoretical GPC curve calculated from the polymerization scheme: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm H}_2 {\rm O} + ({\rm Me}_2 {\rm SiO})_3 \to {\rm HO}({\rm Me}_2 {\rm SiO})_3 {\rm H}} \\ {{\rm HO(Me}_{\rm 2} {\rm SiO)}_{\rm 3} {\rm H} + {\rm N(Me}_{\rm 2} {\rm SiO)}_{\rm 3} \to {\rm HO}({\rm Me}_2 {\rm SiO})_{3(n + 1)} {\rm H}} \\ \end{array} $$\end{document} Polymerization carried out in the combined presence of H₂O and ROH, where R is Me or Me₃Si, gives rise to bimodal molecular weight distributions. The resulting polymers consist of HO(Me₂SiO)_2xH and RO(Me₂SiO)_xH. The molecular weight of the former is twice that of the latter, and their proportion depends on the ratio of H₂O to ROH. The system is a special type of “living” polymer.     

Olefin copolymerization with metallocene catalysts. I. Comparison of catalysts

A number of metallocene/methylaluminoxane (MAO) catalysts have been compared for ethylene/propylene copolymerizations to find relationship between the polymerization activities, copolymer structures, and copolymerization reactivity ratio with the catalyst structures. Stereorigid racemic ethylene bis (indenyl) zirconium dichloride and the tetrahydro derivative exhibit very high activity of 10 ⁷ g (mol Zr h bar)^?1, giving copolymers having comonomer compositions about the same as the feed compositions, molecular weights increasing with the increase of ethylene in the feed, random incorporation of comonomers, and narrow molecular weight distribution indicative of a single catalytic species. Nonbridged bis (indenyl) zirconium behaved differently, favoring the incorporation of ethylene over propylene, producing copolymers whose molecular weight decreases with the increase of ethylene in the feed, broad molecular weight distribution, and a methanol soluble fraction. This catalyst system contains two or more active species. Simple methallocene catalysts have much lower polymerization activities. C_pTiCl₂/MAO produced copolymers with tendency toward alternation, whereas Cp₂HfCl₂/MAO gave copolymer containing short blocks of monomers.     

Polymerization of hexamethylcyclotrisiloxane with a biscatecholsiliconate. II. Kinetics of polymerization

The kinetics of polymerization were investigated for the polymerization of hexamethylcyclotrisiloxane (D₃) in toluene with methanol or water as an initiator, benzyltrimethylammonium bis(o-phenylenedioxy)phenylsiliconate as a catalyst, and dimethyl sulfoxide (DMSO) as a promoter. The rate of initiation was found to be comparable with both water and methanol. Addition of catechol drastically reduces the rate of initiation. The rate of propagation was found to be dependent upon the catalyst, DMSO, catechol and the aging of the catalyst solution. Two types of functional groups were postulated to be present during the propagation reaction, i.e., ?SiOH (dormant form) and ?SiONR₄ (living form). The former can be converted to the latter by R₄NOH derived from hydrolysis of catalyst. A postulated mechanism of polymerization with biscatecholsiliconate is presented.     

Reaction of inorganic cyanates with halides. II. Reactions of chlorohydrins

The reaction of ethylene and trimethylene chlorohydrins with cyanate ion in anhydrous dimethylformamide (DMF) forms 2-oxazolidinone and tetrahydro-2H-1, 3-oxazin-2-one, respectively. These are the major products over a wide concentration range, and at initial chlorohydrin concentration of 1 M and lower, the yields are high enough to make the reaction useful for synthesis of oxazine and oxazolidine derivatives. The corresponding reaction with tetramethylene chlorohydrin gave tetrahydrofuran as the major product with the by-products being polymeric. Pentamethylene and hexamethylene chlorohydrins yield linear polyurethanes when allowed to react with cyanate in DMF. Examination of the relative rates of reaction of these chlorohydrins indicate that the mechanism by which urethanes are formed (both cyclic and polymeric) is an S_N2 displacement of chloride by cyanate ion to give an isocyanate intermediate which then reacts with an alcohol group to form urethane.     

Cation radicals. XXXII. Reaction of N-ethylcarbazole with iodine-silver salts. Nitration of N-ethylcarbazole

Reaction of N-ethylcarbazole ( 1 ) with iodine-silver perchlorate gave a green solution having a singlet esr signal. Reduction of the solution with potassium iodide gave N,N′ -diethyl-3,3′-dicarbazolyl ( 3 , 48%). Small amounts of 3-iodo- ( 4 ) and 3,6-diiodo-N-ethylcarbazole ( 5 ) were also obtained. Compounds 4 and 5 are believed to have been formed by electrophilic iodination of 1 by I₂-AgCIO₄, whereas 3 appears to have been formed via the dimerization of 1 ^.+. In accord with this, reaction of 1 with iodine-silver nitrite gave 3-nitro-N-ethylcarbazole ( 6 , 61%), 9% of another nitro-N-ethylcarbazole ( 7 ), thought to be either 1- or 4-nitro-N-ethylcarbazole, and 28% of 4. Thus, trapping of 1 ^.+ by nucleophilic nitrite ion occurred even though 1 ^.+ is not stable enough toward isolation as the perchlorate.