Syntheses and crosslinking reactions of polymers containing spiroorthoester moieties

The radical copolymerization of unsaturated spiroorthoesters such as 2-methylene-1,4,6-trioxaspiro[4.6]undecane (SOE I) and 2-methylene-9-methyl-1,4,6-trioxaspiro[4,5]decane (SOE II) with vinyl monomers was carried out to find that SOE I and SOE II were copolymerized with electron-poor olefins such as methyl acrylate, acrylonitrile, and methyl methacrylate to obtain the corresponding copolymers containing spiroorthoester moieties, respectively. The obtained copolymers were treated with BF₃.OEt₂ or BzS⁺SbF to afford crosslinked polymers undergoing expansion in volume on crosslinking in those cases of copolymers of SOE I.     

Syntheses, X-ray structures, and reactions of ruthenium carbonyl complexes containing 1,1-dithiolates

Treatment of [Ru₂(CO)₄(MeCN)₆][BF₄]₂ or [Ru₂(CO)₄(μ-O₂CMe)₂(MeCN)₂] with uni-negative 1,1-dithiolate anions via potassium dimethyldithiocarbamate, sodium diethyldithiocarbamate, potassium tert-butylthioxanthate, and ammonium O,O′-diethylthiophosphate gives both monomeric and dimeric products of cis-[Ru(CO)₂(η²-(SS))₂] ((SS)⁻=Me₂NCS₂⁻ (1), Et₂NCS₂⁻ (2), ^tBuSCS₂⁻ (3), (EtO)₂PS₂⁻ (4)) and [Ru(CO)(η²-(Me₂NCS₂))(μ,η²-Me₂NCS₂)]₂ (5). The lightly stabilized MeCN ligands of [Ru₂(CO)₄(MeCN)₆][BF₄]₂ are replaced more readily than the bound acetate ligands of [Ru₂(CO)₄(μ-O₂CMe)₂(MeCN)₂] by thiolates to produce cis-[Ru(CO)₂(η²-(SS))₂] with less selectivity. Structures 1 and 5 were determined by X-ray crystallography. Although the two chelating dithiolates are cis to each other in 1, the dithiolates are trans to each other in each of the {Ru(CO)(η²-Me₂NCS₂)₂} fragment of 5. The dimeric product 5 can be prepared alternatively from the decarbonylation reaction of 1 with a suitable amount of Me₃NO in MeCN. However, the dimer [Ru(CO)(η²-Et₂NCS₂)(μ,η²-Et₂NCS₂)]₂ (6), prepared from the reaction of 2 with Me₃NO, has a structure different from 5. The spectral data of 6 probably indicate that the two chelating dithiolates are cis to each other in one {Ru(CO)(η²-Et₂NCS₂)₂}fragment but trans in the other. Both 5 and 6 react readily at ambient temperature with benzyl isocyanide to yield cis-[Ru(CO)(CNCH₂Ph)(η²-(SS))₂] ((SS)=Me₂NCS₂⁻ (7) and Et₂NCS₂⁻ (8)). A dimerization pathway for cis-[Ru(CO)₂(η²-(SS))₂] via decabonylation and isomerization is proposed.     

Syntheses and crosslinking reactions of self-curable copolymers containing pendant cyclic iminoethers and carboxylic acid groups

Soluble copolymers containing both pendant cyclic iminoethers such as 4,4-dimethyl-2-oxazoline or 4,4,6-trimethyl-4H-dihydro-1,3-oxazine and carboxylic acid were successfully synthesized by radical copolymerizations of 4,4-dimethyl-2-vinyl-2-oxazoline, 4,4-dimethyl-2-isopropenyl-2-oxazoline, or 4,4,6-trimethyl-2-vinyl-4H-dihydro-1,3-oxazine with methacrylic acid and styrene, methyl methacrylate, or ethyl acrylate using AIBN as an initiator in benzene or DMF at 60 or 80°C. The crosslinking reaction of the copolymers obtained did not occur by heating at 70°C. However, these copolymers quantitatively produced gel products by heating at 130°C. The rate of crosslinking reaction of the copolymer increased with increasing pendant cyclic iminoether and carboxylic acid groups. The rate of crosslinking was also affected by the molecular motion of the polymer chain. Our results show that the copolymers of more sterically hindered 2-vinyl-2-oxazolines are more stable and so they can be crosslinked in a controlled manner and at higher temperatures than the previously studied polyoxaziline system.     

Syntheses, reactions, and ethylene polymerization of half-sandwich titanium complexes containing salicylbenzoxazole and salicylbenzothiazole ligands

Half-sandwich titanium salicylbenzoxazole complexes CpTiLCl(2) 2a-2c [L = R-2-(benzo[d]xazol-2-yl)phenol (R = H (2a), R = 6-CH(3) (2b), R = 4-CH(3)-6-(t)Bu (2c)] and salicylbenzothiazole complexes CpTiLCl(2) 2d-2g [L = R-2-(benzo[d]thiazol-2-yl)phenol (R = H (2d), R = 6-CH(3) (2e), R = 6-(t)Bu (2f), R = 4-Cl (2g)] were synthesized by the reaction of CpTiCl(3) with the sodium salts of their corresponding precursors. Complexes 2a-2g were fully characterized by (1)H and (13)C NMR spectra and elemental analyses. The molecular structures of 2a and 2b were determined by single crystal X-ray diffraction methods. When activated by excess methylaluminoxane (MAO) these half-sandwich titanium complexes showed moderate to high activities for ethylene polymerization and produced high molecular weight polyethylenes. The half-sandwich titanium salicylbenzoxazole complexes (2a-2c) exhibited higher activities, of up to 1.23 × 10(6) g PE mol Ti(-1) h(-1) for the 2b/MAO system, than those of their analogues, half-sandwich titanium salicylbenzothiazole complexes (2d-2g).     

Syntheses and reactions of pyrimidine derivatives

By the NMR method, the chemical shifts characterizing the methyl groups in monohydroxymonomethyl derivatives of pyrimidine have been determined. The changes in the chemical shifts and the activities of the methyl groups are symbatic. It has been shown by the NMR method that when 6-hydroxy-2,4-dimethylpyrimidine reacts with benzaldehyde and with p-nitrobenzenediazonium salts reactions take place through the methyl group in position 2. A gradual decrease in the activity of the methyl groups is found in the sequence of 6-hydroxy-, 6-mercapto-, and 6-aminoderivatives of 2,4-dimethylpyrimidine.For part XVII, see [5].     

Syntheses and nucleophilic reactions of N-alkyldiphenylsulfilimines

N-Alkyldiphenylsulfilimines, Ph₂S⁺N^?R, were prepared by treating diphenylsulfilimine with alkyl halides in refluxing chloroform. Reactions of N-benzyldiphenylsulfilimine with activated olefins and acetylenes were investigated and found to give products consistent with nuclephilic attack of ^?NCH₂Ph followed by SN bond cleavage with or without hydrogen transfer. In general, the reaction conditions had a pronounced effect on the product distribution.     

Syntheses,structures and magnetic properties of Mn(II) containing 3D polymeric networks

Two novel 3D coordination polymers {[Mn(aip)(DMF)]}_n, CPO-9, and {[Mn₃(Hatp)₂(atp)₂](H₂O)₂(DEF)₄}_n CPO-10 (aip = 5-aminoisophthalate, atp = 2-aminoterephthalate, DMF = dimethylformamide, DEF = diethylformamide) have been synthesized by solvothermal methods. Their properties have been studied by single-crystal X-ray diffraction, thermogravimetric analysis, high-temperature powder X-ray diffraction and magnetic susceptibility measurements. The crystal structure of CPO-9 is based on infinite chains of carboxylato-bridged five-coordinated Mn(II) ions that are crosslinked via the aip ligands to form a 3D structure. CPO-10 is based on linear trinuclear building units of carboxylato-bridged octahedral Mn(II) ions that are crosslinked by the atp ligands into a 3D structure. Both compounds have 1D channels that contain solvent molecules. The solvent accessible void volume for CPO-10 is 51.9% of the unit cell volume. For both compounds, however, the solvent molecules cannot be removed without the collapse of the structures into amorphous phases at 250 °C. The magnetic susceptibility measurements indicate antiferromagnetic couplings between the Mn(II) ions in both compounds. The magnetic data have been fitted using theoretical approaches.     

Syntheses and reactions of optically active alpha-aminoallenylstannanes

Lithiation/stannylation of optically active N-propargyloxazolidinones produced optically active alpha-oxazolidinonylallenylstannanes. Reaction of these with aldehydes in the presence of BF(3).OEt(2) produced beta-hydroxypropargylamines with high syn diastereoselectivity and ee. These were converted to gamma-hydroxy-beta-amino acids by oxidative cleavage of the alkyne.     

Syntheses of copolymers containing pendant cyclic iminoethers and crosslinking reactions of these copolymers with dithiols and dicarboxylic acids

Copolymers containing pendant cyclic iminoethers were prepared by radical copolymerizations of 2-vinyl-2-oxazoline (VOZO), 5-methyl-2-vinyl-2-oxazoline (MVOZO), 4,4-dimethyl-2-vinyl-2-oxazoline (DMVOZO), 4,4-dimethyl-2-vinyl-5,6-dihydro-4H-1,3-oxazine (DMVOZI), and 4,4,6-trimethyl-2-vinyl-5,6-dihydro-4H-1,3-oxazine (TMVOZI) with styrene, methyl methacrylate (MMA), and ethyl acrylate (EA) using AIBN as an initiator. In addition, the monomer reactivity ratios of VOZO, MVOZO, DMVOZO, and DMVOZI with styrene and MMA were determined. The crosslinking reactions of these copolymers with polyfunctional thiols such as 6-(N,N-dibutyl)amino-1,3,5-triazine-2,4-dithiol (DBDT), 4,4′-oxydi(benzenedithiol) (OBDT), and pentaerythritol tetrathioglycolate (PETT), and dicarboxylic acids such as succinic acid, adipic acid, and sebacic acid were carried out at several reaction temperatures. From these results, it was found that the order of reactivity of pendant cyclic iminoethers to the thiols was VOZO > DMVOZO ≥ DMVOZI > MVOZO > TMVOZI, and that of the cyclic iminoethers to the carboxylic acids was VOZO > MVOZO ≥ DMVOZI > TMVOZI ≥ DMVOZO. Furthermore, the order of reactivity of the thiols to the cyclic iminoethers was DBDT > OBDT > PETT, and that of the dicarboxylic acids to the cyclic iminoethers was succinic acid > adipic acid > sebacic acid.     

Syntheses and reactions of porphyrin and metalloporphyrin polymers

Various porphyrin functions such as protoporphyrin IX and chlorin a as well as metalloporphyrin functions such as Mg(II)– and Cu(II)–chlorophyllin a and Fe(III)– and Co(II)–protoporphyrin IX were incorporated into vinyl polymers by preparation and polymerization of their p-vinylbenzyl esters. The porphyrin function was also incorporated by reaction of poly-p-chloromethylstyrene with porphyrins or metalloporphyrins or by the reaction of p-aminostyrene polymers with chlorophyll b through Schiff-base formation. Mg(II)–porphyrin polymers were found to be remarkably effective as catalysts in photoredox systems; porphyrin polymers without central metal atoms were also effective to a lesser extent.     

Syntheses and reactions of 2-halo-5-thiazolecarboxylates

A variety of 2-halo-5-thiazolecarboxylates was prepared from substituted-3-aminoacrylates and 3-ketoes-ters. Selective reduction of 2-chloro-5-thiazolecarboxylates 4a, 4i and 4j with sodium borohydride in ethanol provided the corresponding 2-halo-5-thiazolemethanols 27-29 . Nucleophilic displacements on [2-chloro-4-(trifluoromethyl)-5-thiazolyl]methyl methanesulfonate ( 32c ) occurred selectively at the 5-substituent to provide 2-chloro-4-(trifluoromethyl)-5-(heteroatom-substituted-methyl)thiazoles 32d-f.     

Syntheses of organometallic monomers containing cobalt and manganese

Direct electrophilic substitution of the cyclopentadienyl ring of cymantrene has been used to prepare five cymantrenyl-monomers with unsaturated sidechains. Direct substitution of cymantrene with acryloyl- and methacryloyl chloride under Friedel-Crafts conditions has led to acryloyl- and methacryloylcymantrene. The complexes have been characterized using ¹H and ¹³C NMR, IR and elemental analysis. Both complexes polymerize under treatment with AIBN at 60–70°C. The chelated complex [n⁵-C₅H₄(CH₂CH=CH₂)]-Co[(NH)₂C₆H₄], was prepared from the treatment of [n⁵-C₅H₄(CH₂CH=CH₂)]Co(CO)₂ with I₂ followed by (NH)₂C₆H₄ and base. The complex was characterized with ¹H NMR and IR but failed to undergo free-radical polymerization. The strategies used to prepare organometallic polymers are discussed.     

Isomerization of the azo-group in a tetrahydro-thiadiazepine

The preparation, isomerization and decomposition of the cis and trans isomer of a heterocyclic azo-compound is described.     

Syntheses and properties of polysulfides containing spiroorthocarbonate moiety

Polysulfides (P_I and P_II) having spiroorthocarbonate moiety in the main chain were synthesized by the polyaddition of unsaturated spiroorthocarbonate ( 1 or 2 ) and dithiols in excellent yields. It is confirmed by DSC and x-ray measurement that P_II is the crystalline polymer. P_I and P_II were treated with a cationic catalyst such as BF₃ · OEt₂ and BzS⁺SbF to afford the crosslinked polymer and to partially undertake the main chain scission. Further, it was also found in the reaction of P_I and P_II with adipoyl chloride as the crosslinking reagent that P_I underwent cleavage of the main chain, but P_II mainly gave crosslinked polymers.     

Syntheses and evaluation of biodegradable multifunctional polymer networks

The biodegradable, injectable and in situ crosslinkable polymer networks based upon di(propylene fumarate)-dimethacrylate (DPFDMA) and polycaprolactone trimethacrylate (PCLTMA), were prepared and characterized. The polymer networks were initiated by photopolymerization. The initial compressive (CS) and diametral tensile strengths (DTS) of the networks materials were determined and used to evaluate the effects of PCLTMA/DPFDMA ratios on the degradation behavior. The networks exhibited initial DTS values ranging from 2.5 to 9.3 MPa and CS values ranging from 1.8 to 146.0 MPa. The increase of PCLTMA in the formulation led to an increase in viscosity and DTS. The degree of conversions and polymerization shrinkage of the resins ranged from 60% to 72% and 5.1% to 6.4%, respectively. After 6 month, PCL300TMA/DPFDMA resins at a ratio of 100/0, 75/25 and 25/75 lost 70%, 87% and 46% of their initial CS, respectively, while PCL900TMA/DPFDMA and PCL300TMA/PCL900TMA resins at 75/25 lost 100% and 83% of their initial CS, respectively.     

Syntheses and reactions of some 2,3-disubstituted pyrazine monoxides

The reactions of 2,3-dimethyl- ( 4 ), 2,3-diphenyl- ( 6 ), and 2-methyl-3-phenyl-pyrazine monoxides ( 8 and 9 ) with phosphoryl chloride and acetic anhydride resulted in giving monochloro- and monacetoxy-pyrazines in almost all cases. However, the reaction of 6 with acetic anhydride afforded exceptionally a diacetoxydihydro-pyrazine. These products were converted further to hydroxy or dichloro derivatives.     

Syntheses,structures, and reactions of di- and tetrahydropyrroles

PMR spectroscopy showed that 2,4,4-trimethyl-, 2,4,4-trimethyl-3-carbethoxy-, and 2,4,4-trimethyl-3-acetyl-¹-pyrrolines usually exist in solutions exclusively in the imine form, regardless of the polarity of the solvents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 475–478, April, 1971.     

Syntheses and reactions of terpene β-hydroxyselenides and β-hydroxydiselenides

A convenient method for the synthesis of optically active trans-hydroxyselenides and trans-hydroxydiselenides from the bicyclic terpene group based on the reactions of sodium selenide or sodium diselenide with cis- and trans-(+)-3-carane, trans-(+)-2-carane and (?)-β-pinane epoxides is described. The corresponding cis-hydroxy and cis-methoxydiselenides were obtained in the reaction of sodium diselenide with β-hydroxy- and β-methoxytosylates. The influence of a hydroxy group at the β-position on the diastereomeric ratio of the products of the asymmetric methoxyselenenylation of styrene has been established by composition of the products, crystal structure analyses, and theoretical calculations using a DFT method on the B3LYP level (6-311G(d)).     

Syntheses and transformations of novel nitrogen and sulfur containing morphinanedienes

Summary The synthesis of 6-azido-6-demethoxythebaine (10) has been performed starting from thebaine (1). Compound10 undergoes a cycloaddition reaction with the azadienophilePTAD to form bridgehead azide14. The acid catalyzed rearrangement of isothiocyanato diene11 obtained from azido diene10 and thiocyanato dienes8 and9 leads to sulfur containing derivatives of apocodeine (17–20).

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Darstellung und Reaktionen stickstoff- und schwefelhaltiger Morphinandiene

Zusammenfassung 6-Azido-6-demethoxythebain (10) wurde ausgehend von Thebain (1) hergestellt. Verbindung10 wurde in einer Cycloadditionsreaktion mit dem AzadienophilPTAD zum Brückenkopfazid14 umgesetzt. Das aus dem Azidodien10 erhältliche Isothiocyanatodien11 und die bereits früher gewonnenen Thiocyanatodiene8 und9 liefern bei säurekatalysierter Umlagerung die Apokodeinderivate17–20.