以三乙酸甘油酯为底物制备光学活性戊醇的探索

1前言(S)-2-甲基-1-丁醇在手性精细化学品及药物合成中有重要的作用[1]。从20世纪90年代起,国外的(R,S)-2-甲基-1-丁醇拆分方面做了一些有益的尝试。Ayter Sagiroglu等人利用固定化脂肪酶催化三丁酸甘油酯与(R,S)-2-甲基-1-丁醇发生不对称酯交换反应,可制备e.e.为98%的(S)-2-甲基-1-丁醇[2]。同时我们的研究表明,无溶剂体系中,以猪胰脂肪酶或酵母脂肪酶为催化剂,三丁酸甘油酯为底物,拆分(R,S)-2-甲基-1-丁醇,可制备e.e.值大于90%的(S)-2-甲基-1-丁醇[3]。采用三丁酸甘油酯,虽然所得产品e.e.较高,但其价格昂贵(1000元/kg)、反应周期较长…     

手性螺二氢茚双膦配体在钌催化酮的不对称氢化反应中的应用研究

羰基化合物的不对称催化氢化是获得光学活性醇类化合物的极为有效的方法之一.在对芳基烷基酮的不对称催化氢化反应的研究中,Noyori等开发出一种非常有效的不对称催化氢化体系,即手性双膦-钌-双胺催化体系.该催化体系是一个具有高转化数、高转化频率以及高对映选择性的催化体系,它能催化氢化烷基酮、芳基酮、杂环芳酮等多种含羰基的潜手性底物[1].我们研究小组合成了一类具有螺二氢茚骨架的手性螺环双膦配体SDP,当这类配体应用于该氢化反应时,不但获得了极高的对映选择性(最高达99.5?),而且转化数也很高(TON高达100000)[2].在研究RuCl2-[(S)-Xyl-SDP][R,R)-DPEN)]络合物催化氢化芳基烷基酮时,发现当用NaOBu-t作碱时,催化氢化反应的速度明显比用KOBu-t作碱时要快.这与Hartmann和Chen等[3]在RuCl2-[(S)-BINAP][(S,S)-DPEN]催化氢化苯乙酮反应中的结果正好相反.我们进一步采用动力学的方法,深入研究了碱金属阳离子对苯乙酮催化氢化反应速率的影响.研究结果表明:双膦配体中P-芳环上的取代基对碱金属阳离子影响氢化反应速率的顺序产生明显影响.     

Ru-(S)-BINAP/γ-Al2O3催化剂上苯乙酮及其衍生物的多相不对称加氢反应

 在温和条件下制备了Ru-(S)-BINAP/γ-Al2O3催化剂,考察了其催化苯乙酮及其衍生物不对称加氢的活性. 在KOH-异丙醇溶液中,在c(KOH)=0.04 mol/L,氢气压力5 MPa和10 ℃条件下,(1S,2S)-DPEN手性修饰剂修饰的Ru-(S)-BINAP/γ-Al2O3催化剂具有较高的活性和对映选择性,反应28 h后苯乙酮的转化率可达100%,(R)-苯乙醇的ee值可达75.0%.     

铑/(2S,2'S,3S,3'S)-3,3'-二叔丁基-4,4'-二甲氧基-2,2',3,3'-四氢-2,2'-联苯并[d][1,3]草酰膦(Me O-BIBOP)催化的不对称还原烯胺合成(R)-3-叔丁氧羰基氨基-4-(2,4,5-三氟苯基)丁酸

(R)-3-氨基-4-(2,4,5-三氟苯基)丁酸是重要的药物中间体,因此发展其高立体选择性的合成方法极具有实用价值.通过实验研究发现[Rh(NBD)_2]~+BF_4~-/(2S,2'S,3S,3'S)-3,3'-二叔丁基-4,4'-二甲氧基-2,2',3,3'-四氢-2,2'-联苯并[d][1,3]草酰膦(Me O-BIBOP)催化剂对N-乙酰基烯胺酯的氢化具有较高的立体选择性,达到99%ee.反应以2,4,5-三氟苯乙酸(1)为起始原料,与米氏酸(2)经缩合、醇解、缩合、氨基乙酰化、不对称氢化、水解和氨基保护合成目标产物,总收率达到61%,纯度达到99.62%,为其放大生产提供了实用和高效的合成方法.     

D-(R)-酪氨酸的不对称催化氢化合成及其在药物合成中的应用

以最近开发的双膦-铑配合物[Rh((R,R)-QuinoxP*)(cod)]SbF6作为催化剂,利用不对称催化氢化方法合成了一系列D-(R)-酪氨酸衍生物,在S/C=10000条件下获得了99%ee的对映选择性.并将所得的氢化产物成功应用于具有重要生理活性的化合物(R)-2-羟基-3-(3,4-二羟基苯基)丙酸钠的合成.相比于已报道的方法,该工艺路线产率更高而且不需要柱层析分离,因而非常具有工业化应用前景.     

用手性Rh(Ⅰ)复合物由3-甲基-2-氧代丁酸多相光催化不对称合成L-α-缬氨酸

本文研究了在甲醇和氨水的水溶液里,手性的(+)-diop-Rh(Ⅰ)复合物(diop:2,3-邻-异亚丙基-2,3-二羟基-1,4-双(二苯膦基)丁烷)作为不对称催化剂,粉末半导体CdS、TiO₂、Pt/CdS和Pt/TiO₂为光催化剂,用500WXe灯光照10h,3-甲基-2-氧代丁酸光催化不对称合成L-α缬氨酸已经实现,光学纯度最高达64%e.e.。     

含桥连Se-Se基团和两个(S2C2B10H10)2-离子的不饱和双核钌化合物与1-乙炔基环己醇的反应性

在二氯甲烷中,化合物(p-cymene)Ru2(μ-Se2)(S2C2B10H10)2 (1)与1-乙炔基环己醇反应得到加成产物(p-cymene)-Ru2(μ-Se2)(S2C2B10H10)2 (R1C=CR2) [R1 =H,R2=(cyclo-C6H10)(OH)(2)；R1=(cyclo-C6H10)(OH),R2=H(3)].化合物2和3在氯仿中加热回流可脱水分别生成4和5,二者在甲苯中进一步加热回流可实现相互转化.所有化合物中,炔烃碳碳三键选择性地加成在两个不同的(S2C2B10H10)2-配体的硫原子[S(2)和S(3)]上,从而使混合价双钌中心RuⅡ/RuⅣ(18e/16e)转变为单一价态的RuⅡ/RuⅡ (18e/18e),得到进一步稳定的配合物.所有化合物通过元素分析、质谱、核磁共振进行了表征,并解析了化合物2的X衍射单晶结构.     

Preparation and Characterization of A New Dinuclear Ruthenium Complex with BDPX Ligand and Its Catalytic Hydrogenation Reactions for Cinnamaldehyde

Introduction Recently, dinuclear Ru complexes containing chelating bidentate phosphines (either chiral or non-chiral) have attracted more and more attention owing to their effective ability for catalytic hydrogenation of olefins and carbonyl groups under mild conditions. A great number of dinuclear Ru complexes with bidentate phosphines have been obtained.1-10 In 1985 Ikariya et al.1 prepared a chiral binuclear ruthenium complex [Ru2Cl4(BINAP)2]NEt3 by the reaction of (S)-BINAP with [R…     

手性双膦配体（4S,5S）—（—）—DIOP的合成

不对称催化是由潜手性反应物合成光活性化合物的有效途径,α,β-不饱和氨基酸的氢化立体选择性已达90％以上,L-Dopa的工业化生产则标志着不对称催化氢化开始走向实际应用。高选择性的催化剂一般是一价铑的手性双膦配体络合物,其中DIOP[2,3-O-异丙叉-     

可回收(S)-脯氨醇衍生物在催化查尔酮类化合物不对称环氧化反应中的催化性能研究

将以L-脯氨酸为原料合成的光学活性脯氨醇衍生物((S)-2-吡咯烷基-α,α-二(α-萘基)甲醇1),作为有机小分子催化剂,在催化8种α,β-不饱和酮的不对称环氧化反应中表现出较好的立体选择性(58.0~84.6?)和催化活性(58.0~89.7%).反应结束后,通过简单的酸碱调整,可使催化剂回收和重复使用.循环使用5次,催化剂的回收率均在93~97%之间,催化剂的催化活性和立体选择性无明显改变.     

Intramolecular C-N bond formation reactions catalyzed by ruthenium porphyrins: amidation of sulfamate esters and aziridination of unsaturated sulfonamides

Ruthenium porphyrins [Ru(F(20)-TPP)(CO)] (F(20)-TPP = 5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato dianion) and [Ru(Por*)(CO)] (Por = 5,10,15,20-tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-octahydro-1,4:5,8-dimethanoanthracen-9-yl]porphyrinato dianion) catalyzed intramolecular amidation of sulfamate esters p-X-C(6)H(4)(CH(2))(2)OSO(2)NH(2) (X = Cl, Me, MeO), XC(6)H(4)(CH(2))(3)OSO(2)NH(2) (X = p-F, p-MeO, m-MeO), and Ar(CH(2))(2)OSO(2)NH(2) (Ar = naphthalen-1-yl, naphthalen-2-yl) with PhI(OAc)(2) to afford the corresponding cyclic sulfamidates in up to 89% yield with up to 100% substrate conversion; up to 88% ee was attained in the asymmetric intramolecular amidation catalyzed by [Ru(Por)(CO)]. Reaction of [Ru(F(20)-TPP)(CO)] with PhI[double bond]NSO(2)OCH(2)CCl(3) (prepared by treating the sulfamate ester Cl(3)CCH(2)OSO(2)NH(2) with PhI(OAc)(2)) afforded a bis(imido)ruthenium(VI) porphyrin, [Ru(VI)(F(20)-TPP)(NSO(2)OCH(2)CCl(3))(2)], in 60% yield. A mechanism involving reactive imido ruthenium porphyrin intermediate was proposed for the ruthenium porphyrin-catalyzed intramolecular amidation of sulfamate esters. Complex [Ru(F(20)-TPP)(CO)] is an active catalyst for intramolecular aziridination of unsaturated sulfonamides with PhI(OAc)(2), producing corresponding bicyclic aziridines in up to 87% yield with up to 100% substrate conversion and high turnover (up to 2014).     

Ru-Catalyzed asymmetric hydrogenation of alpha-ketoesters with CeCl3.7H2O as additive

[reaction: see text] An efficient asymmetric hydrogenation of alpha-ketoesters is reported with use of a catalyst prepared from [Ru((S)-3)(benzene)Cl]Cl and CeCl(3).7H(2)O. Alpha-hydroxy esters are obtained in up to 96% ee. The addition of CeCl(3).7H(2)O not only improves the enantioselectivity, but also enhances the stability of the catalyst. As a result, the hydrogenation of methyl benzoylformate affords the product with 92% ee with a substrate/catalyst ratio of 10 000. Hydrolysis of 2 provides the final compound with 83% yield at 99% ee after a single recrystallization from 1,2-dichloroethylene.     

Structural determination of ruthenium-porphyrin complexes relevant to catalytic epoxidation of olefins

A reproducible synthesis of a competent epoxidation catalyst, [Ru(VI)(TPP)(O)2)] (TPP = tetraphenylporphyrin dianion), starting from [Ru(II)(TPP)(CO)L] (L = none or CH3OH), is described. The molecular structure of the complex was determined by using ab initio X-ray powder diffraction (XRPD) methods, and its solution behavior was in detail investigated by NMR techniques such as PGSE (pulsed field gradient spin-echo) measurements. [Ru(IV)(TPP)(OH)]2O, a reported byproduct in the synthesis of [Ru(VI)(TPP)(O)2], was synthesized in a pure form by oxidation of [Ru(II)(TPP)(CO)L] or by a coproportionation reaction of [Ru(VI)(TPP)(O)2] and [Ru(II)(TPP)(CO)L], and its molecular structure was then determined by XRPD analysis. [Ru(VI)(TPP)(O)2] can be reduced by dimethyl sulfoxide or by carbon monoxide to yield [Ru(II)(TPP)(S-DMSO)2] or [Ru(II)(TPP)(CO)(H2O)], respectively. These two species were characterized by conventional single-crystal X-ray diffraction analysis.     

对烷氧基取代 MeO-BIPHEP 型手性双膦钌配合物催化 β-酮酸酯不对称加氢反应

 报道了对烷氧基取代的 MeO-BIPHEP 型手性双膦配体钌配合物催化的β-酮酸酯不对称加氢反应, 考察了反应温度、压力、底物/催化剂摩尔比和溶剂对反应的影响. 结果表明, 在乙醇中该配合物催化 3-丁酮酸乙酯加氢反应的对映选择性达 98.0%,且对含不同取代基的β-酮酸酯均表现出较高的活性和对映选择性.     

Reactivity and catalytic activity of a robust ruthenium(II)-triphos complex

The ruthenium(II)-triphos acetato complex [RuCl(OAc)(kappa3-triphos)] (triphos = (PPh2CH2)3CMe) has been found to be an active catalyst precursor for the hydrogenation of 1-alkenes under relatively mild conditions (5-50 bar H2, 50 degrees C). In contrast to related triphenylphosphine complexes, [RuCl(OAc)(kappa3-triphos)] is much less air sensitive and high catalytic activities were achieved when catalyst samples were prepared without exclusion of air or moisture. Substitution of the acetato ligand can be effected by treatment of acid, affording [Ru2(mu-Cl)3(kappa3-triphos)2]Cl and [RuCl(kappa3-triphos)]2(BF4)2 with aqueous HCl and [Et2OH]BF4, respectively, or by heating with dmpm in the presence of [NH4]PF6, resulting in formation of [RuCl(kappa2-dmpm)(kappa3-triphos)]PF6 (dmpm = PMe2CH2PMe2). A hydride complex, [RuHCl(kappa3-triphos)], formed by acetato-mediated heterolytic cleavage of dihydrogen is proposed as the active catalytic species. An inner-sphere, monohydride mechanism is suggested for the catalytic cycle, with chloro and triphos ligands playing a spectator role. These mechanistic proposals are consistent with reactivity studies carried out on [RuCl(OAc)(kappa3-triphos)] and [RuH(OAc)(kappa3-triphos)] and supported by a computational analysis. The solid-state structures of [RuCl(OAc)(kappa3-triphos)], [RuCl(kappa3-triphos)]2(BF4)2, and [RuCl(kappa2-dmpm)(kappa3-triphos)]PF6 have been established by X-ray diffraction.     

Amidation of unfunctionalized hydrocarbons catalyzed by ruthenium cyclic amine or bipyridine complexes

Selective amidation of simple hydrocarbons with pre-isolated and in-situ formed iminoiodanes catalyzed by ruthenium complexes [Ru(III)(Me(3)tacn)(CF(3)CO(2))(3).H(2)O] (2b, Me(3)tacn = N,N', N"-trimethyl-1,4,7-triazacyclononane) and cis-[Ru(II)(6, 6'-Cl(2)bpy)(2)Cl(2)] (3, 6,6'-Cl(2)bpy = 6,6'-dichloro-2, 2'-bipyridine) was investigated. With PhI=NTs as nitrogen source, both catalysts efficiently promote the amidation of adamantane, cyclohexene, ethylbenzene, cumene, indan, tetralin, and diphenylmethane to afford N-substituted sulfonamides in 80-93% yields with high selectivity. Competitive amidations of para-substituted ethylbenzenes and kinetic isotope effect for the amidation of cyclohexene/cyclohexene-d(10) suggest that the amidation processes probably proceed via the hydrogen abstraction by a reactive Ru=NTs species to form a carboradical intermediate. The amidation with PhI(OAc)(2)/TsNH(2) gave results comparable to those obtained with PhI=NTs. Extension of the "PhI(OAc)(2)/TsNH(2) + catalyst 2b or 3" protocol to MeSO(2)NH(2) and PhCONH(2) with ethylbenzene as substrate produced the corresponding N-substituted amides in up to 89% yield.     

Water oxidation intermediates applied to catalysis: benzyl alcohol oxidation

Four distinct intermediates, Ru(IV)═O(2+), Ru(IV)(OH)(3+), Ru(V)═O(3+), and Ru(V)(OO)(3+), formed by oxidation of the catalyst [Ru(Mebimpy)(4,4'-((HO)(2)OPCH(2))(2)bpy)(OH(2))](2+) [Mebimpy = 2,6-bis(1-methylbenzimidazol-2-yl) and 4,4'-((HO)(2)OPCH(2))(2)bpy = 4,4'-bismethylenephosphonato-2,2'-bipyridine] on nanoITO (1-PO(3)H(2)) have been identified and utilized for electrocatalytic benzyl alcohol oxidation. Significant catalytic rate enhancements are observed for Ru(V)(OO)(3+) (~3000) and Ru(IV)(OH)(3+) (~2000) compared to Ru(IV)═O(2+). The appearance of an intermediate for Ru(IV)═O(2+) as the oxidant supports an O-atom insertion mechanism, and H/D kinetic isotope effects support net hydride-transfer oxidations for Ru(IV)(OH)(3+) and Ru(V)(OO)(3+). These results illustrate the importance of multiple reactive intermediates under catalytic water oxidation conditions and possible control of electrocatalytic reactivity on modified electrode surfaces.     

Preparation and characterization of a family of Ru2 compounds bearing iodo/ethynyl substituents on the periphery

A high-yield synthesis of mixed-bridging-ligand Ru2 compounds, Ru2(D(3,5-Cl2Ph)F)(4-n)(OAc)nCl [n = 1 (1) and 2 (2)] was developed, where D(3,5-Cl2Ph)F is bis(3,5-dichlorophenyl)formamidinate. The acetate ligands in 1 and 2 can be quantitatively displaced with DMBA-I to yield Ru2(D(3,5-Cl2Ph)F)3(DMBA-I)Cl (3) and Ru2(D(3,5-Cl2Ph)F)2(DMBA-I)2Cl (4), respectively, where DMBA-I is N,N'-dimethyl-4-iodobenzamidinate. When compound 2 was treated with 1 equiv of HDMBA-I, a unique Ru2 compound containing three different types of bidentate bridging ligands, cis-Ru2(D(3,5-Cl2Ph)F)2(DMBA-I)(OAc)Cl (5), was obtained. Subsequent reactions between 3/4 and (trimethylsilyl)acetylene under Sonogashira coupling conditions resulted in Ru2(D(3,5-Cl2Ph)F)(4-n)(DMBA-C[triple bond]CSiMe3)nCl [n = 1 (6) and 2 (8)] in excellent yields, which were converted to the corresponding bis(phenylacetylide) compounds Ru2(D(3,5-Cl2Ph)F)(4-n)(DMBA-C[triple bond]CSiMe3)n(C[triple bond]CPh)2 [n = 1 (7) and 2 (9)]. Structural studies of several compounds provided insights about the change in Ru2 coordination geometry upon the displacement of bridging and axial ligands. Voltammetric studies of these compounds revealed rich redox characteristics in all Ru2 compounds reported and a minimal electronic perturbation upon the peripheral Sonogashira modification.     

Origins of cooperative noncovalent host-guest chemistry in mixed valence complexes

The electronic effects resulting from noncovalent host-guest interactions between calix[6]arene and a ruthenium dimer, [Ru3O(OAc)6(CO)(ppy)]2-mu-pz (ppy=4-phenyl pyridine, pz=pyrazine), are presented. The noncovalent interaction is between the calix[6]arene and the ppy ligands of the dimer. The dimer can bind 2 equiv of calix[6]arene. The complex [Ru3O(OAc)6(CO)(ppy)]2-mu-pz forms a highly stable mixed valence ion with strong electronic coupling between the two Ru3 clusters. The strength of the electronic interaction is found to be moderated by calix[6]arene binding. Addition of calix[6]arene to the mixed valence ion causes the electronic coupling to decrease. The binding of calix[6]arene is found to be cooperative. The origins of cooperative binding are developed in terms of the potential energy surfaces associated with the symmetric and asymmetric mixed valence ion. In particular, it is found that symmetry breaking (through the binding of a single calix[6]arene) destabilizes the mixed valence state. Restoration of symmetry (through the binding of a second calix[6]arene) increases the stability of the mixed valence ion and provides an additional driving force for the binding of the second calix[6]arene.     

Synthesis and characterization of palladium(II) complexes with new diphosphonium-diphosphine and diphosphine ligands. Production of low molecular weight alternating polyketones via catalytic CO/ethene copolymerisation

The bis-cationic diphosphonium-diphosphine 6,7-di(di-2-methoxyphenyl)phosphinyl-2,2,4,4-tetra(di-2-methoxyphenyl)-2 lambda 4,4 lambda 4-diphosphoniumbicyclo[3.1.1]heptane-bis(PF6) ((o-MeO-PCP)(PF6)2) and the diphosphine rac-2,4-bis((di-2-methoxyphenyl)phosphino)pentane (rac-o-MeO-bdpp) have been synthesized. Both ligands have been employed to coordinate PdCl2 and Pd(OAc)2 to give [PdCl2(o-MeO-PCP)](PF6)2 (1a), PdCl2(rac-o-MeO-bdpp) (1b), [Pd(OAc)2(o-MeO-PCP)](PF6)2 (2a) and Pd(OAc)2(rac-o-MeO-bdpp) (2b). The ligands and complexes have been fully characterized in solution by multinuclear NMR spectroscopy. In addition, 1a and 1b have been authenticated by single crystal X-ray structure analyses. The Pd(II) complexes 1a and 1b have been employed as catalyst precursors for the CO/ethene copolymerisation in water-acetic acid mixtures, while 2a and 2b have been tested in methanol in the presence of p-toluenesulfonic acid. Irrespective of the reaction media, perfectly alternating polyketones were obtained in excellent yields and with number-average molecular weights ranging from 7.1-13.9 kg mol(-1) with the diphosphonium-diphosphine catalysts and from 37.2-48.2 kg mol(-1) with the diphosphine catalysts.