新型负载水相催化剂（SAPC）的制备及其在丙烯氢甲酰化反应中的应用

以新型水溶性二磺化 - 1-苯基二苯并膦 (简称 PDBPDS)为配体 ,制备了铑膦配合物 Rh(acac) (CO ) -(PDBPDS) 3.将其负载于高吸水性载体上 ,制得负载水相催化剂 ,并对催化剂的制备条件进行了优化 .以人造沸石为载体 ,在载水量 30 % ,[Rh]=2 .0× 10 - 5、 [P]/ [Rh]=40的条件下 ,筛选出丙烯氢甲酰化反应的最佳工艺条件 .在反应温度 10 0℃、压力 2 .0 MPa、搅拌速度为 5 0 0 r/ m in条件下 ,催化剂活性达 10 12 g丁醛 / (g Rh· h) ;正异比高达 43.5 ;在有机相中铑的浓度为 1.2× 10 - 9,解决了均相反应催化剂回收和循环使用的问题 .实验结果表明 ,新型配体二磺化 - 1-苯基二苯并膦是一性能较好的新配体 ,所制备的新型负载水相催化剂是一有较好开发前景的新型催化剂     

Rh-TPPTS/CTAB-MMT催化剂的制备及其催化长链烯烃氢甲酰化反应性能研究

通过浸渍法将水溶性铑膦配合物(Rh-TPPTS)负载到由十六烷基三甲基溴化铵(CTAB)修饰的蒙脱土(MMT)上,制备出Rh-TPPTS/CTAB-MMT负载型催化剂.采用XRD,FTIR,TG,BET,31P CP-MAS NMR和分散性实验对催化剂进行了表征.结果表明:水溶性铑膦配合物成功地负载到有机MMT上,并且该催化剂在有机溶剂中具有很好的分散性.该催化剂对于1-癸烯的氢甲酰化反应具有好的催化活性.在100℃、4 MPa、甲苯为溶剂的条件下,催化1-癸烯氢甲酰化可获得93.0%的转化率,95.8%的醛的选择性,2.1的正异比,137 h-1的TOF值.并对不同链长烯烃底物进行了考察.随着烯烃碳链的增加,醛的选择性下降,但是正异比有所增加.     

超细SiO2负载型水溶性铑膦配合物催化剂研究

用超细SiO2负载水溶性铑膦配合物,并研究其对1-已烯氢甲酰化的催化性能。结果表明,粒径为10-20nm的超细SiO2负载水溶性铑膦配合物所表现的催化活性比颗粒SiO2负载型催化剂高3倍多,且可在较宽的含水量范围内保持高反应活性。当膦铑摩尔比为50,超细SiO2负载型催化剂含水量为25%-55%（质量分数）、烯铑摩尔比为2500、反应温度373K和CO/H2（1/1,体积比）压力4.0MPa的反应条件下,其1-已烯氢甲酰化的反应转化数为450h^-1,产物醛的选择性为100%,醛的n/i比值达3.2。     

金属离子对RhCl（CO）（TPPTS）2催化1—己烯氢甲酰化反应的影响

在以水溶性铑－膦配合物为催化剂的烯烃氢甲酰化反应中,铑的存在形态及配位结构对烯烃氢甲酰化反应的转化率及选择性起着决定性的作用．在反应过程中,特别是工业生产过程中,会由于各种原因导致一些杂质进入反应体系,这些杂质可能会影响铑－膦配合物催化剂的性质,改变...     

聚氧乙烯基取代膦—铑配合物催化有机单相苯乙烯氢甲酰化反应研究

基于非离子表面活性膦配体的临界溶解温度特性 ,研究了以 Rh Cl3· 3H2 O为催化剂前体、聚氧乙烯基取代膦为配体原位合成的膦铑配合物催化剂 ,对有机单相体系中苯乙烯氢甲酰化反应的催化性能 .考察了反应温度、压力及不同聚氧乙烯基取代膦 -铑配合物催化剂对反应的影响 .以 Rh/PETPP配合物为催化剂时 ,在 T=10 0℃ ,p=6 .0 MPa (CO/H2 =1∶ 1)条件下 ,反应 3.5 h后 ,烯烃转化率和产物醛收率可分别达 96 .7%和 92 .6 %     

新型膦配体PDBPDS在氢甲酰化反应中催化剂配体性能的研究

用量子化学 AMI方法优化了 1 -苯基二苯并膦二磺化产物 ( PDBPDS)和三磺化三苯基膦 ( TPPTS)的几何构型 .比较两种化合物的空间结构和电子结构发现 ,在氢甲酰化铑膦催化反应体系中 ,PDBPDS的配体性能优于 TPPTS.首次研究了以 PDBPDS为配体的铑膦催化剂对丙烯氢甲酰化反应的催化性能 ,考察了反应温度、压力、膦铑物质的量比和搅拌速度对催化活性和选择性的影响 .结果表明 ,在 2 .0 MPa,1 0 0℃ ,膦铑物质的量比为 35 ,搅拌速度为 5 0 0 r/min及 V( H2 ) /V( CO) =1 /1的条件下 ,催化活性可达到 2 80 0 g(丁醛 ) /[g(铑 )·h],正异构产物物质的量比为 1 2 .3,在相同条件下与传统的三磺化三苯基膦 ( TPPTS)为配体的铑膦催化剂相比 ,催化活性和选择性提高了 2倍 .反应结束后 ,有机相和水相分离简单 ,有机相铑浓度仅为3.6× 1 0 - 8mol/L,有效地解决了铑流失问题 ,表明 PDBPDS是极具开发前景的新型水溶性配体     

水溶性铑膦配合物催化烯烃氢甲酰化反应研究进展

 水/有机两相体系中水溶性铑膦配合物催化的烯烃氢甲酰化反应由于具有环境友好和催化剂容易分离等优点而受到广泛关注. 其中水溶性催化剂体系已经用于丙烯氢甲酰化反应制备丁醛的工业化生产. 然而, 长链烯烃在含有催化剂的水相中溶解性较差, 反应速率较慢. 综述了有关加速水/有机两相体系中长链烯烃氢甲酰化反应的方法和进展, 包括使用具有表面活性的膦配体, 以及在催化体系中添加环糊精和表面活性剂等促进剂. 另外, 还讨论了有关内烯烃氢甲酰化反应和提高直链醛选择性的方法.     

新型水溶性膦铑络合物催化烯烃的氢甲酰化反应研究

新型水溶性膦铑络合物催化烯烃的氢甲酰化反应研究燕远勇，左焕培，金子林（大连理工大学化工学院，大连１１６０１２）关键词烯烃，水溶性膦铑络合催化剂，氢甲酰化，醛．１．前言为克服催化剂的流失和与反应产物的分离困难，近年来均相催化的一个重要进展是开发了以磺化...     

双膦配体DPPB的铑配合物催化烯烃氢甲酰化反应研究(2000年版)

研究了由 Rh(acac) (CO) 2 和 1 ,4-双 (二苯膦基 )苯 (简称 DPPB)组成的体系对烯烃氢甲酰化反应的催化作用 .考察了反应温度、压力、P/Rh比、催化剂浓度等对 1 -己烯氢甲酰化反应的影响 ,得到了较适宜的反应条件 .在相同条件下比较了该体系催化 1 -己烯、 1 -辛烯、 1 -十二烯的氢甲酰化反应的性能 .结果表明 ,随着底物碳链的增长 ,反应活性呈提高趋势 .实验证明 ,DPPB-铑配合物对苯乙烯的氢甲酰化反应有较高的催化活性和选择性 .     

SiO2负载的磺化三苯膦铑配合物催化高碳烯氢甲酰化

本文将水溶性磺化三苯基膦铑配合物催化剂负载在SiO_2表面使其复相化,考察不同制备方法制得催化剂的性能及对反应活性和选择性的影响。这种负载化水溶性Wilkinson催化剂比表面积较大,可在适当过量配体存在下保持较高的催化活性;当液态高碳烯烃十一烯酸甲酯和1-己烯在固定床加压流动态反应器中连续进行氢甲酰化催化反应时,产物醛的选择性大于95%;正异醛比(n/i值)随P/Rh摩尔比的提高而提高P/Rh=15,产物中正构醛大于或接近80%(n/i为4)。P/Rh>15后,配体增多几乎不再提高产物n/i值,而影响反应速度。     

钒促铑基催化剂上合成气反应中的H2／D2同位素效应

铑基催化剂可催化合成气生成甲烷、乙醇等,CO中C—O键断裂是该反应的关键步骤。Ⅴ助剂可显著提高Rh的催化活性,其作用本质被认为是促进了CO的直接解离。本文考察了Ⅴ助剂对Rh催化性能的影响及Rh/SiO_2、Rh-V(1:1)/SiO_2上合成气反应的H_2/D_2同位素效应,根据实验结果及键级守恒-Morse势法的计算结果初步探讨了Ⅴ助剂的作用本质。     

Mechanism of the

Stereochemical studies on [2 + 2] photoaddition of cis-/trans-4-propenylanisole (cis-1 and trans-1) and cis-1-(p-methoxyphenyl)ethylene-2-d(1) (cis-3-d(1)) to C(60) exhibit stereospecificity in favor of the trans-2 cycloadduct in the former case and nonstereoselectivity in the latter. The observed stereoselectivity in favor of the cis-6-d(3) [2 + 2] diastereomer by 12% in the case of the photochemical addition of (E)-1-(p-methoxyphenyl)-2-methyl-prop-1-ene-3,3,3-d(3) (trans-5-d(3)) to C(60) is attributed to a steric kinetic isotope effect (k(H)/k(D) = 0.78). The loss of stereochemistry in the cyclobutane ring excludes a concerted addition and is consistent with a stepwise mechanism. Intermolecular secondary kinetic isotope effects of the [2 + 2] photocycloaddition of 3-d(0) vs 3-d(1), and 3-d(6) as well as 5-d(0) vs 5-d(1), and 5-d(6) to C(60) were also measured. The intermolecular competition due to deuterium substitution of both vinylic hydrogens at the beta-carbon of 3 exhibits a substantial inverse alpha-secondary isotope effect k(H)/k(D) = 0.83 (per deuterium). Substitution with deuterium at both vinylic methyl groups of 5 yields a small inverse k(H)/k(D) = 0. 94. These results are consistent with the formation of an open intermediate in the rate-determining step.     

Mechanistic studies of olefin and alkyne trimerization with chromium catalysts: deuterium labeling and studies of regiochemistry using a model chromacyclopentane complex

A system for catalytic trimerization of ethylene utilizing chromium(III) precursors supported by diphosphine ligand PNP(O4) = (o-MeO-C6H4)2PN(Me)P(o-MeO-C6H4)2 has been investigated. The mechanism of the olefin trimerization reaction was examined using deuterium labeling and studies of reactions with alpha-olefins and internal olefins. A well-defined chromium precursor utilized in this studies is Cr(PNP(O4))(o,o'-biphenyldiyl)Br. A cationic species, obtained by halide abstraction with NaB[C6H3(CF3)2]4, is required for catalytic turnover to generate 1-hexene from ethylene. The initiation byproduct is vinylbiphenyl; this is formed even without activation by halide abstraction. Trimerization of 2-butyne is accomplished by the same cationic system but not by the neutral species. Catalytic trimerization, with various (PNP(O4))Cr precursors, of a 1:1 mixture of C2D4 and C2H4 gives isotopologs of 1-hexene without H/D scrambling (C6D12, C6D8H4, C6D4H8, and C6H12 in a 1:3:3:1 ratio). The lack of crossover supports a mechanism involving metallacyclic intermediates. Using a SHOP catalyst to perform the oligomerization of a 1:1 mixture of C2D4 and C2H4 leads to the generation of a broader distribution of 1-hexene isotopologs, consistent with a Cossee-type mechanism for 1-hexene formation. The ethylene trimerization reaction was further studied by the reaction of trans-, cis-, and gem-ethylene-d2 upon activation of Cr(PNP(O4))(o,o'-biphenyldiyl)Br with NaB[C6H3(CF3)2]4. The trimerization of cis- and trans-ethylene-d2 generates 1-hexene isotopomers having terminal CDH groups, with an isotope effect of 3.1(1) and 4.1(1), respectively. These results are consistent with reductive elimination of 1-hexene from a putative Cr(H)[(CH2)4CH=CH2] occurring much faster than a hydride 2,1-insertion or with concerted 1-hexene formation from a chromacycloheptane via a 3,7-H shift. The trimerization of gem-ethylene-d2 has an isotope effect of 1.3(1), consistent with irreversible formation of a chromacycloheptane intermediate on route to 1-hexene formation. Reactions of olefins with a model of a chromacyclopentane were investigated starting from Cr(PNP(O4))(o,o'-biphenyldiyl)Br. alpha-Olefins react with cationic biphenyldiyl chromium species to generate products from 1,2-insertion. A study of the reaction of 2-butenes indicated that beta-H elimination occurs preferentially from the ring CH rather than exo-CH bond in the metallacycloheptane intermediates. A study of cotrimerization of ethylene with propylene correlates with these findings of regioselectivity. Competition experiments with mixtures of two olefins indicate that the relative insertion rates generally decrease with increasing size of the olefins.     

Scope and mechanistic study of the ruthenium-catalyzed ortho-C-H bond activation and cyclization reactions of arylamines with terminal alkynes

The cationic ruthenium hydride complex [(PCy(3))(2)(CO)(CH(3)CN)(2)RuH](+)BF(4)(-) was found to be a highly effective catalyst for the C-H bond activation reaction of arylamines and terminal alkynes. The regioselective catalytic synthesis of substituted quinoline and quinoxaline derivatives was achieved from the ortho-C-H bond activation reaction of arylamines and terminal alkynes by using the catalyst Ru(3)(CO)(12)/HBF(4).OEt(2). The normal isotope effect (k(CH)/k(CD) = 2.5) was observed for the reaction of C(6)H(5)NH(2) and C(6)D(5)NH(2) with propyne. A highly negative Hammett value (rho = -4.4) was obtained from the correlation of the relative rates from a series of meta-substituted anilines, m-XC(6)H(4)NH(2), with sigma(p) in the presence of Ru(3)(CO)(12)/HBF(4).OEt(2) (3 mol % Ru, 1:3 molar ratio). The deuterium labeling studies from the reactions of both indoline and acyclic arylamines with DCCPh showed that the alkyne C-H bond activation step is reversible. The crossover experiment from the reaction of 1-(2-amino-1-phenyl)pyrrole with DCCPh and HCCC(6)H(4)-p-OMe led to preferential deuterium incorporation to the phenyl-substituted quinoline product. A mechanism involving rate-determining ortho-C-H bond activation and intramolecular C-N bond formation steps via an unsaturated cationic ruthenium acetylide complex has been proposed.     

Activation of alkenes and H2 by [Fe]-H2ase model complexes

The established ability of the Fe(II) bridging hydride species (micro-H)(micro-pdt)[Fe(CO)2(PMe3)]2+, 1-H+, to take-up and heterolytically activate dihydrogen, resulting in H/D scrambling of H2/D2 and H2/D2O mixtures (Zhao et al. Inorg. Chem. 2002, 41, 3917) has prompted a study of simultaneous alkene/H2 activation by such [Fe]H2ase model complexes. That the required photolysis produced an open site was substantiated by substitution of CO in 1-H+ by CH3CN with formation of structurally characterized [(micro-H)(micro-pdt)[Fe(CO)2(PMe3)][Fe(CO)(CH3CN)(PMe3)]]+[PF6]-. Under similar photolytic conditions, H/D exchange reactions between D2 and terminal alkenes (ethylene, propene and 1-butene), but not bulkier alkenes such as 2-butene or cyclohexene, were catalyzed by 1-H+ and the edt (SCH2CH2S) analogue, 2-H+. Substantial regioselectivity for H/D exchange at the internal vinylic hydrogen was observed. The extent to which the olefins were deuterium enriched vs deuterated was catalyst dependent. The stabilizing effect of the binuclear chelating ligands, SCH2CH2CH2S, pdt, and SCH2CH2S, edt, is required for the activity of binuclear catalysts, as the mono-dentate micro-SEt analogue decomposed to inactive products under the photolytic conditions of the catalysis. Reactions of 1 and 2 with EtOSO2CF3 yielded the S-alkylated products, [(micro-SCH2CH2CH2SEt)[Fe(CO)2(PMe3)]2]+[SO3CF3]- (1-Et+), and 2-Et+, rather than micro-C2H5 analogues to the micro-H of 1-H+. The stability and lack of reactivity toward H2 of 1-Et+ and 2-Et+, indicates they are not on the reaction path of the olefin/D2 H/D exchange process. A mechanism with olefin binding to an open site created by CO loss and formation of an Fe-(CH2CHDR) intermediate is indicated. A likely role of a binuclear chelate effect is implicated for the unique S-XXX-S cofactor in the active site of [Fe]H2ase.     

Uncoupled forms of tyrosine hydroxylase unmask kinetic isotope effects on chemical steps

Tyrosine hydroxylase (TyrH) catalyzes the hydroxylation of tyrosine to dihydroxyphenylalanine. In the proposed mechanism, a ferryl-oxo species attacks the aromatic ring of tyrosine, forming a cationic intermediate. However, no significant isotope effect is found for wild-type TyrH when 3,5-2H2-tyrosine is used as a substrate. The isotope effect has now been determined with 3,5-2H2-tyrosine using mutant forms of TyrH in which the oxidation of the pterin is uncoupled from hydroxylation of the amino acid. Three mutant enzymes exhibit significant inverse deuterium isotope effects and inverse solvent isotope effects. A proton inventory for the E326A enzyme is consistent with a normal solvent isotope effect of 2.4 on an unproductive step. The results support the proposed mechanism and demonstrate the utility of using mutant proteins with branched pathways to reveal isotope effects which are masked in the wild-type enzyme.     

A novel thermoregulated phosphine ligand used for the Rh-catalyzed hydroformylation of mixed C11~12 olefins in aqueous/organic biphasic system

<正>A novel thermoregulated phosphine ligand Ph_2P(CH_2CH_2O)_nCH_3(n=22) was synthesized and used for the Rh-catalyzed hydroformylation of mixed C_(11-12) olefins in aqueous/organic biphasic system.Under the optimized conditions,pressure =5 MPa (H_2:CO=1:1),phosphine/Rh =13(molar ratio),reaction time =6 h and temperature =130℃,the conversion of C_(11-12) olefins and the yield of aldehyde are 99%and 94%,respectively.The catalyst retained in aqueous phase can be easily separated from the product-containing organic phase by simple phase separation and the catalytic activity remains almost constant after four consecutive cycles.     

Room-temperature regioselective C-H/olefin coupling of aromatic ketones using an activated ruthenium catalyst with a carbonyl ligand and structural elucidation of key intermediates

Mechanistic studies of the ruthenium-catalyzed reaction of aromatic ketones with olefins are presented. Treatment of the original catalyst, RuH(2)(CO)(PPh(3))(3), with trimethylvinylsilane at 90 °C for 1-1.5 h afforded an activated ruthenium catalyst, Ru(o-C(6)H(4)PPh(2))(H)(CO)(PPh(3))(2), as a mixture of four geometric isomers. The activated complex showed high catalytic activity for C-H/olefin coupling, and the reaction of 2'-methylacetophenone with trimethylvinylsilane at room temperature for 48 h gave the corresponding ortho-alkylation product in 99% isolated yield. The activated catalyst was thermally robust and showed excellent catalytic activity under refluxing toluene conditions. (1)H and (31)P NMR studies of the C-H/olefin coupling at room temperature suggested that an ortho-ruthenated complex, P,P'-cis-C,H-cis-Ru(2'-(6'-MeC(6)H(4)C(O)Me))(H)(CO)(PPh(3))(2), participated in the reaction as a key intermediate. Isotope labeling studies using acetophenone-d(5) indicated that the rate-limiting step was the C-C bond formation, not the C-H bond cleavage, and that each step prior to the reductive elimination was reversible. The rate of C-H/olefin coupling was found to exhibit pseudo first-order kinetics and to show first-order dependence on the ruthenium complex concentration.     

Some organometallic chemistry of ruthenium(II)

Stoichiometric and catalytic reaction of Ru(II) phosphine complexes with alkynes, olefins, and enynes are described. The hydride complex RuCl(CO)H(PPh₃)₃ (1) reacts with the double bond of a cis-enyne whereas it reacts with triple bonds of trans-enynes. Metathesis of vinyl silanes with olefins are catalyzed by 1 where β-Si elimination is the key step. Dimerizations of ^tBu- and Me₃Si-substituted acetylanes into the corresponding butatrienes are catalyzed by Ru(II) active species as studied by isolation of the intermediates. A model reaction for the crucial step of the catalytic cycle, formation of a Ru vinylidene complex from acetylene, has been fully simulated by ab initio-MO calculations.     

Kinetics of the thiazolium ion-catalyzed benzoin condensation.

The formation of benzoin (Ph-CHOH-CO-Ph) from two molecules of benzaldehyde, catalyzed by 3-benzyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide in methanol buffered with Et(3)N/Et(3)NH(+)Cl(-) has been studied. Initial-rate studies at various concentrations of PhCHO (0.1-1.7 M) showed that the reaction is close to being first order in PhCHO. Following the reaction in deuteriomethanol, (1)H NMR spectroscopy allowed rate constants for all three kinetically significant steps to be determined. These show that all three steps are partially rate-determining. A normal deuterium kinetic isotope effect for the overall reaction (k(H)/k(D) approximately 3.4) is observed using PhCDO, and a large inverse solvent isotope effect (k(D)/k(H) approximately 5.9) is observed using deuteriomethanol, consistent with the kinetic scheme presented here.