Catalytic hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol at atmospheric pressure in the liquid phase

Selective hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol on suspended palladium and Raney nickel catalysts at atmospheric pressure was studied. The optimal parameters of this reaction were determined. Samples containing 90% 2-butene-1,4-diol were prepared.     

Effect of structure on the thermal degradation and flame retardancy of hexolic anhydride based polyesters

Based on the anhydrides like hexolic (5,6,7,8,10,10-hexachloro -3a,4,4a,5,8,8a,9,9a-octahydro-5,8-methanonaphtho-[2,3-c]-furan-1,3-dione), maleic and phthalic and diols like 1,4-butanediol, cis-2-butene-1,4-diol and 2,3-dichloro-2-butene-1,4-diol, a family of polyesters has been synthesized using azeotropic condensation technique. The structural characterizations of the polyesters have been carried out using infra-red, 1^H - and ¹³C- nuclear magnetic resonance spectroscopic methods. The thermal properties of the polyesters have been studied using thermogravimetric technique. The off-line pyrolysis of these materials was done. The qualitative and semi-quantitative analyses of the volatiles as well as the heavy mass fractions of the degradation products were carried out using a gas chromatograph coupled to a mass selective detector (GC-MSD). Thermogravimetric data indicate that the thermal stability and the char residue of the polyester resins decrease in the order 1,4-butanediol based>cis-2-butene-1,4-diol based>2,3-dichloro-2-butene-1,4-diol based polyesters. The GC-MSD data indicate that the amount of flame cooling agents (hexa-, isomeric penta-, tetra- and isomeric tri-chlorocyclopentadienes) produced during the pyrolysis of the polyesters increases in the order 2,3-dichloro-2-butene-1,4-diol based<cis-2-butene-1,4-diol based<1,4-butanediol based polyesters. The trends observed in these two parameters which are contributing factors to the flame retardancy of the polyester materials were suitably explained on the basis of the effect of the structural changes in the diol part of the polyesters on the primary degradation mechanism, the β-chain scission process.     

Palladium-catalyzed regiospecific tandem allylation of 2-aminophenols using 2-butene-1,4-diol

The direct activation of C-O bonds in 2-butene-1,4-diol by palladium complexes has been accelerated by carrying out the reactions in the presence of a titanium reagent. Palladium-catalyzed regiospecific tandem allylation of 2-aminophenols with 2-butene-1,4-diol leads to 3,4-dihydro-2-vinyl-2H-1,4-benzoxazines.     

Electrolytic reduction of 2-butyne-1,4-diol as a route to trans-2-butene-1,4-diol

The effect of the cathode material on the electrochemical transformations of 2-butyne-1,4-diol at atmospheric pressure was studied by chromatographic analysis. The optimal parameters of the selective synthesis of trans-2-butene-1,4-diol were determined.     

纳米Pd的形貌和尺寸可控制备及其1,4-丁炔二醇加氢性能

采用化学还原法合成Pd纳米立方体,并将其作为晶种,进一步合成大尺寸的纳米Pd立方体以及具有不同{100}和{111}晶面比例的纳米Pd多面体.将形貌和尺寸可控的纳米Pd溶胶应用于1,4-丁炔二醇催化加氢的反应中,反应结果表明,纳米Pd的催化性能取决于其尺寸和形貌.{111}晶面的催化活性高于{100}晶面,PVP稳定的Pd胶体对1,4-丁烯二醇均具有较高选择性,具有适当{100}和{111}晶面比例的纳米Pd多面体对1,4-丁烯二醇的选择性可达96%.     

Preparation and Study of Some Copolyesters

Terephthalate unsaturated copolyesters with ethylene glycol and 2-butene-1,4-diol, with ethylene glycol and 2-butyne-1,4-diol, with ethylene glycol and diethylene glycol, and with 2-butyne-1,4-diol were synthesized by trans-esterification reactions. Proton nuclear magnetic resonance spectroscopy was used to elucidate the structures of the copolyesters. The intrinsic viscosities of the copolyesters were measured in o-chlorophenol at 30°C. The number-average molecular weights of these copolyesters were determined by using a vapor pressure osmometer. The thermal behaviors of the copolyesters were studied by differential thermal analysis and are discussed in terms of structural differences.     

Enantioselective synthesis of R-(+)-α and S-(−)-α-lipoic acid

An efficient synthesis of α-lipoic acid from the readily available cis-2-butene-1,4-diol employing a Claisen orthoester rearrangement and Sharpless asymmetric dihydroxylation as the key steps, is described.     

Stereochemistry of additions to a triple bond

Summary In the photochemical bromination of 2-butene-1,4-diol, its diacetate, and 2,5-dimethyl-3-hexene-2,5-diol in nonpolar solvents, trans-addition products are formed, whereas their acetylenic analogs give mainly cis-dibromides. The differences in the behavior of acetylenes and the corresponding olefins are to be explained on the view that under identical conditions they may react by different mechanisms. Thus, under given conditions 2-butyne-1,4-diol diacetate is brominated by a chain mechanism, whereas the corresponding olefin is brominated by a nonchain mechanism.     

A concise and stereoselective synthesis of (+)- and (−)-deoxoprosophylline

An efficient synthesis of (+)- and (−)-deoxoprosophylline was accomplished from the readily available cis-2-butene-1,4-diol in which the Sharpless asymmetric dihydroxylation was used as the key step.     

Functional Acetal Methacrylates: III. Electrophilic Addition of Diols to 2-(Vinyloxy)ethyl Methacrylate

Reactions of 2-(vinyloxy)ethyl methacrylate with diols [ethylene glycol, diethylene glycol, triethylene glycol, oligoethylene glycol-400, Z-2-butene-1,4-diol, 2-butyne-1,4-diol, 1,1,3,3-tetramethyl-1,3-bis(3-hydroxypropyl)disiloxane, 2,2-bis(4-hydroxyphenyl)propane] and polyols (glycerol, pentaerythritol) under electrophilic conditions (1 wt% of CF₃COOH, 20-60°C, 1-3 h) result in quantitative formation of functional acetal methacrylates.     

Highly efficient and diastereoselective synthesis of 1,3-oxazolidines featuring a palladium-catalyzed cyclization reaction of 2-butene-1,4-diol derivatives and imines

A palladium-catalyzed protocol for effective synthesis of 1,3-oxazolidines has been reported. This method is featured by the high diastereoselectivity (dr up to >98/2) and using the readily available 2-butene-1,4-diol derivatives and imines as substrates.     

Polycondensation of butenediol: synthesis of telechelic 2-butene-1,4-diol oligomers

The catalytic condensation of cis-2-butene-1,4-diol with CpRu(MQA)(C(3)H(5)) (Cp = cyclopentadienyl, MQA = 4-methoxyquinoline-2-carboxylate) generates poly(2-butenediol), an unsaturated telechelic polyether diol with molecular weights between 400 and 4600 g/mol. This Ru(IV) allyl catalyst enchains 2-butene-1,4-diol primarily as the linear trans-2-butenyl ether (92%) along with vinyl branches (8%). These telechelic oligomers are useful chain extenders and macromonomers, as demonstrated by their use in the synthesis of poly(lactide)-b-poly(butenediol)-b-poly(lactide) triblock copolymers. Model studies support a proposed mechanism involving the formation of Ru(IV) allyl intermediates from allylic alcohols and chain growth by selective nucleophilic displacement at the terminus of the Ru(IV) allyl to generate trans-2-butenyl ether linkages.     

Reductive cleavage of C-OH bonds in allyl position-formation of gaseous products in the course of the cathodic reduction of some simple unsaturated alcohols

The problem of the reductive cleavage of C?OH bonds in allyl position has been considered starting from the literature data concerning the behaviour of allyl alcohol. The formation of hydrocarbons has been shown in the case of the electroreduction of crotyl alcohol, 2-butene-1,4-diol, propargyl alcohol, 2-butyne-1,4-diol and 1-butyne-3-ol. The composition of the gaseous products was analyzed, current efficiency values with respect to the hydrocarbon formation were calculated. Schemes for the reduction path were given.     

Second virial coefficients of a polymer of 2-butene-2,3-dibromo-1,4-diol with adipic acid from light scattering measurements in benzene

Light scattering measurements of a polymer of 2-butene-2,3-dibromo-1,4-diol with adipic acid in benzene have been made in the temperature range 283.15–333.15 K. The second virial coefficients and excess thermodynamic functions have been calculated.     

A concise enantioselective synthesis of 1,4-dideoxy-1,4-imino-d-arabinitol using Co(III)(salen)-catalyzed hydrolytic kinetic resolution of a two-stereocentered anti-azido epoxide

A concise enantioselective synthesis of 1,4-dideoxy-1,4-imino-d-arabinitol, (+)-DAB-1, has been described in good overall yield (18.1%) and with high enantiomeric purity (up to 98% ee) starting from a simple raw material, cis-2-butene-1,4-diol. The Co-catalyzed hydrolytic kinetic resolution of a two-stereocentered racemic azido epoxide followed by asymmetric dihydroxylation of the alkene and ‘one pot’ reductive cyclisation of the azido diol are key reactions in the synthetic sequence.     

A concise synthesis of (+)-deoxoprosophylline via Co(III)(salen)-catalyzed two stereocentered HKR of racemic azido epoxides

An efficient synthesis of (+)-deoxoprosophylline has been achieved in high optical purity (99% ee) from readily available cis-2-butene-1,4-diol. The strategy employs Co-catalyzed Hydrolytic Kinetic Resolution (HKR) of two stereocentered racemic azido epoxides and diastereoselective intramolecular reductive cyclization as key reactions.     

An efficient stereoselective synthesis of (2S,4S,5R)-(−)- and (2R,4R,5S)-(+)-bulgecinine

A short synthetic route to (−)-and (+)-bulgecinine, the amino acid moiety of the bulgecins was achieved from the readily available nonchiral pool starting material cis-2-butene-1,4-diol in which a Claisen orthoester rearrangement and a Sharpless asymmetric dihydroxylation were used as the key steps.     

Asymmetric total synthesis of (2S,3S)-3-hydroxypipecolic acid

A synthetic route to (2S,3S)-3-hydroxypipecolic acid was achieved from readily available nonchiral pool starting material cis-2-butene-1,4-diol and involved Claisen orthoester rearrangement, Sharpless asymmetric dihydroxylation and intramolecular lactamisation of azido lactone as the key steps.     

Stereocontrolled synthesis of the aminocyclitol moiety of (+)-trehazolin via C-H insertion reaction of alkylidenecarbene

The aminocyclitol moiety of (+)-trehazolin, a powerful trehalase inhibitor, was synthesized in a stereocontrolled manner from cis-2-butene-1,4-diol via C-H insertion reaction of the alkylidenecarbene, followed by regioselective opening of the epoxide ring. It was obtained in an enantiomerically pure form by twice using Sharpless asymmetric epoxidation.     

Stereoselective synthesis of (+)-1-deoxyaltronojirimycin

A stereocontrolled, facile and high-yield approach for producing (+)-altroDNJ, has been developed starting from the inexpensive commercial cis 2-butene-1,4-diol. Sharpless epoxidation and a subsequent dihydroxylation were used for the introduction of all stereocentres; finally, the ring closure under basic conditions afforded the piperidine heterocycle.