光学纯的cis,cis-2,2′-螺二氢茚-1,1′-二醇和2,2′-螺二氢茚-1,1′-二酮的合成

以丙二酸二乙酯和苄氯为起始原料,通过改进拆分方法,成功地合成了光学纯cis,cis-2,2′-螺二氢茚-1,1′-二醇(e.e.≥99%)和2,2′-螺二氢茚-1,1′-二酮(e.e.≥98%),收率较高。     

光学纯的cis,cis-2,2''''-螺二氢茚-1,1''''-二醇和2,2''''-螺二氢茚-1,1''''-二酮的合成

以丙二酸二乙酯和苄氯为起始原料,通过改进拆分方法,成功地合成了光学纯cis,cis-2,2'-螺二氢茚-1,1'-二醇(e.e.≥99%)和2,2'-螺二氢茚-1,1'-二酮(e.e.≥98%),收率较高.     

新型螺双二氢茚二酚衍生物的合成

螺双二氢茚二酚(SPINOL)与N-溴代丁二酰亚胺经溴代反应制得6,6'-二溴-螺双二氢茚二酚(1);1与叔丁基二甲基硅基三氟甲磺酸(TBSOTf)经醚化反应得6,6'-二溴-7-羟基-7'-叔丁基二甲硅氧基-1,1'-螺二氢茚(2);SPINOL经羟基保护后与碘甲烷经双甲基化反应制得6,6'-二甲基-7,7'-双(1-甲氧甲氧基)-1,1'-螺二氢茚(4);4经脱保护后再与TBSOTf经醚化反应合成了6,6'-二甲基-7-羟基-7'-叔丁基二甲硅氧基-1,1'-螺二氢茚(6)。2和6为新化合物,其结构经1H NMR,13C NMR和HR-ESI-MS表征。     

5,5′-二甲基-2,2′-二茚满-1,1′,3,3′-四酮的合成及结构表征

2,2′-二茚满-1,1′,3,3′-四酮(1)是合成茚满类光致磁性材料[1]的重要中间体, 在军事目标识别、特殊防伪以及光信息存储等领域具有潜在的应用价值, 因此取代的2,2′-二茚满-1,1′,3,3′-四酮的合成已成为人们研究的焦点.     

两个基于氮、膦混合配体的铜(Ⅰ)配合物的合成、光谱学性质和太赫兹时域光谱

在甲醇和二氯甲烷的混合溶剂中合成了2个新的铜(1)配合物,[Cu(bdppmapy)(2,2′-bipy)]BF4(1)和[Cu(bdppmapy)(2,2′-bipy)]I (2)(bdppmapy=N,N-二苯基膦甲基-2-氨基吡啶,2,2′-bipy=2,2′-联吡啶),通过X射线单晶衍射、元素分析、核磁共振氢谱、磷谱、荧光光谱和太赫兹时域光谱对2个配合物进行了分析和表征。1是由[Cu(CH3CN)4]BF4,bdppmapy和2,2′-bipy以1∶1∶1的比例混合得到的单核配合物。中心Cu(1)离子通过与双膦配体(bdppmapy)以及含氮配体(2,2′-bipy)的螯合作用形成变形四面体结构。与1相似,2由CuI,bdppmapy和2,2′-bipy以1∶1∶1的比例混合得到。在配合物2的非对称单元中,bdppmapy和2,2′-bipy配体分别与中心铜(1)离子螯合。荧光光谱表明所有的发射峰均源于金属-配体的荷移跃迁(MLCT)。太赫兹时域光谱的应用也为配合物研究提供了有用的信息。     

光诱导有机化合物异构化反应的研究——Ⅹ. 吲哚啉螺吡喃瞬态吸收光谱的研究

研究了1-正-辛基-3,3-二甲基-吲哚啉-2,2′-螺-5′,6′-(2-溴-4-硝基-苯并)吡喃, 1-正-辛基-3,3-二甲基-吲哚啉-2,2′-螺-5′,6′-(4-硝基-苯并)吡喃, 1-正-辛基-3,3-二甲基-吲哚啉-2,2′-螺-5′,6′-(2,4-二硝基-苯并)吡喃及1-正-辛基-3,3-二甲基-吲哚啉-2,2′螺-5′6′-(2-氯-4-硝基-苯并)吡喃在环已烷和甲苯溶液中光致开环过程的瞬态吸收光谱。观察到具有较长寿命的中间体及聚集体的存在。初步提出异构化反应过程的机制中既包含有三重态过程, 也有单重态参与。     

基于功能化6-甲氧羰基-2,2'-联吡啶配体的铜(Ⅰ)铁(Ⅱ)异金属双核配合物

以[Cu(CH_3CN)_4]ClO_4、6-甲氧羰基-2,2′-联吡啶(mbpy)、6-甲氧羰基-4,4′-二甲基-2,2′-联吡啶(mmbpy)和1,1′-双(二苯基膦)二茂铁(dppf)为起始原料,合成得到了2个新的铜(Ⅰ)铁(Ⅱ)异金属双核配合物:[Cu(mbpy)(dppf)]ClO_4·CH_2Cl_2(1)和[Cu(mmbpy)(dppf)]ClO_4(2)。X射线单晶衍射分析表明,配合物1和2均为铜(Ⅰ)铁(Ⅱ)异金属双核配合物,并且均表现为四配位变形四面体构型。配合物1和2在330~520 nm波长范围有一个弱的低能量宽吸收峰,其主要来源于金属到配体的电荷转移跃迁(MLCT)。由于1,1′-双(二苯基膦)二茂铁的引入,配合物1和2常温下在溶液和固态时均未检测到任何发光。     

含半夹心结构铑的1,1'-二硫(硒、碲)二茂铁化合物

以半夹心结构铑的化合物Cp*Rh(CN^tBu)Cl2(1)(Cp*=η^5-C5Me5)与Fe(C5H4ELi)2.2THF反应,合成出异双核二茂铁化合物Cp*Rh(CN^tBu)(EC5H4)2Fe[E=S(2),Se(3),Te(4)]。通过AgBF4氧化2和3得到二茂铁离子型化合物[Cp*Rh(CN^tBu)(EC5H4)2Fe]BF4[E=S(5),Se(6)]。采用元素分析、红外光谱、^1H和13CNMR谱以及EI-MS表征了所合成的化合物。     

螺旋共轭分子2,2′-螺二茚-1,1′, 3,3′-四酮及其衍生物的二阶非线性光学性质与分子结构关系的研究

采用AM1和ZINDO系列方法研究了螺旋共轭分子2,2′-螺二茚-1,1′, 3,3′-四酮及其含氮衍生物的几何构型和各分子的稳定构型, 并以稳定构型为基础, 计算了这些分子的电子光谱、二阶非线性光学系数βμ, β0及电荷转移, 考察了取代基变化对βμ的影响. 计算结果表明, 所设计分子兼具较大的二阶非线性光学系数和较高的透过率, 有希望成为一类新型的二阶非线性光学材料.     

9,9-(′1,4-亚苯基)十四氢-二-吖啶-1,1,′8,8′-四酮缩双季戊四醇的合成

利用1,3-环己二酮和1,4-苯二甲醛为原料,在微酸介质中通过羟醛缩合和脱水反应,合成了9,9′-(1,4-亚苯基)-2H,2′H,3H,3′H,4H,4′H,5H,5H,′6H,6′H,7H,7′H,9H,9′H-十四氢-二-吖啶-1,1,′8,8′-四酮(化合物Ⅰ)。提出了化合物Ⅰ生成的反应机理。将化合物Ⅰ与季戊四醇在I2催化下反应,生成了目标化合物9,9-(′1,4-亚苯基)-2H,2′H,3H,3′H,4H,4′H,5H,5H,′6H,6′H,7H,7′H,9H,9′H-十四氢-二-吖啶-1,1,′8,8′-四酮缩双季戊四醇(化合物Ⅱ),收率为40%。产物和中间体用IR1、H NMR、MS和元素分析进行了结构表征。在含有螺环单元的化合物Ⅱ1H NMR中,亚甲基中的8个氢由于受手性轴和苯环的影响而裂分成8重峰。对影响反应的因素特别是副产物生成的原因进行了探讨     

BINAP: rhodium–diolefin complexes in asymmetric hydrogenation

The complexes [Rh((S)-BINAP)(COD)]BF₄ 1, [Rh((S)-BINAP)(NBD)]BF₄ 2, [Rh((R)-BINAP)(COD)]OTf 3, [Rh((R)-BINAP)(NBD)]OTf 4, and [Rh((R)-BINAP)(COD)]BArF 5 were synthesized, and 1–4 were analyzed by single crystal X-ray crystallography. The transformation of these precatalysts into hydrogenation-active species was investigated as well as the hydrogenation of prochiral olefins. In particular, this series of transformations was investigated with regard to solvent and counterions.     

Synthesis and reactivity of fluoro complexes: Part 2. Rhodium(I) fluoro complexes with alkene and phosphine ligands. Synthesis of the first isolated rhodium(I) bifluoride complexes. Structure of [Rh3(mu3-OH)2(COD)(3)](HF2) by X-ray powder diffraction

The reaction between [Rh(mu-OH)(COD)](2) (COD = 1,5-cyclooctadiene) and 73% HF in THF gives [Rh(3)(mu(3)-OH)(2)(COD)(3)](HF(2)) (1). Its crystal structure, determined by ab initio X-ray powder diffraction methods (from conventional laboratory data), contains complex trimetallic cations linked together in 1D chains by a mu(3)-OH...F-H-F...HO-mu(3) sequence of strong hydrogen bonds. The complex [Rh(mu-F)(COE)(2)](2) (COE = cyclooctene; 2), prepared by reacting [Rh(mu-OH)(COE)(2)](2) with NEt(3).3HF (3:2), has been characterized. Complex 1 reacts with PR(3) (1:3) to give [RhF(COD)(PR(3))] [R = Ph (3), C(6)H(4)OMe-4 (4), (i)Pr (5), Cy (6)] that can be prepared directly by reacting [Rh(mu-OH)(COD)](2) with 73% HF and PR(3) (1:2:2). The reactions of 1 with PPh(3) or Et(3)P have been studied by NMR spectroscopy at different molar ratios. Complexes [RhF(PEt(3))(3)] (7), [RhF(COD)(PEt(3))] (8), and [RhF(PPh(3))(3)] (9) have been detected. The complex [Rh(F)(NBD)(iPr(3)P)] (NBD = norbornadiene; 10) was prepared by the sequential treatment of [Rh(mu-OMe)(NBD)](2) with 1 equiv of NEt(3).3HF and (i)Pr(3)P. The first isolated bifluoride rhodium(I) complexes [Rh(FHF)(COD)(PR(3))] [R = Ph (11), (i)Pr (12), Cy (13)], obtained by reacting fluoro complexes 3, 5, and 6 with NEt(3).3HF (3:1), have been characterized. The crystal structures of 3 and 11 have been determined.     

Synthesis,characterization and catalytic applications of rhodium(I) organometallics with substituted tertiary phosphines

Organometallics of the type [Rh(COD)(L)Cl] (where, L = carboxyl/formyl/pyridyl tertiary phosphines) have been synthesized by treating the precursor [Rh(COD)Cl]₂ with substituted tertiary phosphines. [Rh(COD)(Ph₂P-2-C₆H₄COO)] and [Rh(COD)(Ph₂P-CH₂COO)] were synthesized by halide abstraction from the precursor [Rh(COD)Cl]₂ in the presence of AgPF₆ in tetrahydrofuran by involving 2-carboxy phenyl/carboxy methyl group of tertiary phosphines in coordination as bidentate ligands. Similarly, the cationic compounds of the type [Rh(COD)L₂]PF₆ were also synthesized by treating [Rh(COD)Cl]₂ in the presence of AgPF₆. All these compounds were characterized by elemental analysis, conductance measurements, IR, ¹H, ¹³C, ³¹P NMR, mass, and electronic spectral studies. [Rh(COD)(Ph₂-P-2-C₆H₄COOH)Cl] and [Rh(COD)(Ph₂-P-2-C₆H₄COO)] were studied on the catalytic reduction reactions of 2-nitroanisole, 3-nitro anisole, 4-nitroanisole, 2-nitrobenzoicacid, 3-nitrobenzoicacid, 4-nitrobenzoicacid under mild conditions and [Rh(COD)(Ph₂-P-2-C₆H₄COO)] was found to be more efficient than [Rh(COD)(Ph₂-P-2-C₆H₄COOH)Cl]. This article is dedicated to Dr. D. R. M Walton, who successfully completed his tenure as Editor-in-Chief, Transition Metal Chemistry.     

Synthesis and reactions of binuclear diolefin rhodium(I) compounds bridged by nitrogen heterocycles. Crystal structure of dichloro-di-1,5-cyclooctadiene(μ-pyrazine)-dirhodium(I) [{Rh(1,5-C8H12)Cl}2(μ-C4H4N2)]

Binuclear complexes of rhodium(I) of the type [(dien)(X)Rh(μ-N-N)Rh(X)(dien)] (dien = 1,5-cyclooctadiene or norbornadiene; N-N = pyrazine, 4,4′-bipyridine or Phenazine and X = Cl or Br) with bridging heterocycles have been isolated and their reactions with carbon monoxide, 2,2′-bipyridine and 1,10-phenanthroline investigated. The crystal structure of [(COD)(Cl)Rh(μ-pyrazine)Rh(Cl)(COD)] has been determined.     

New ligand systems incorporating two and three 4,4'-bipyridine units. Characterization of bi- and trimetallic rhodium and iridium complexes

The synthesis of new ligand systems based on the bipyridine unit for bi- and trimetallic complexes, including a rare example of a chiral bimetallic complex, is presented. Ligands BBPX (bis-bipyridine-xylene, 3) and TBPBX (tris-bipyridine-bis-xylene, 4) were prepared in one step by reacting alpha,alpha'-dibromo-o-xylene (2) with 2 equiv of the monolithiated derivative of 4,4'-dimethyl-2,2'-bipyridine. Dilithium (S)-binaphtholate (5) reacted with 2 equiv of 4-bromomethyl-4'-methyl-2,2'-bipyridine (6), affording ligand (S)-BBPBINAP (bis-bipyridine-binaphtholate, 7). These ligands reacted cleanly with 1, 1.5, and 1 equiv of the rhodium dimer [Rh(2)Cl(2)(HD)(2)] (HD = 1,5-hexadiene), respectively. Chloride abstraction led to the isolation of the cationic complexes BBPX[Rh(HD)BF(4)](2) (8), TBPBX[Rh(HD)BF(4)](3) (10), and (S)-BBPBINAP[Rh(HD)BF(4)](2) (12). When BBPX (3), TBPBX (4), and (S)-BBPBINAP (7) were added to 2, 3, and 2 equiv of [Rh(NBD)(2)]BF(4) or [Rh(NBD)(CH(3)CN)(2)]BF(4) (NBD = norbornadiene), respectively, clean formation of BBPX[Rh(NBD)BF(4)](2) (9), TBPBX[Rh(NBD)BF(4)](3) (11), and (S)-BBPBINAP[Rh(NBD)BF(4)](2) (13) was observed. The neutral iridium complex (S)-BBPBINAP[IrCl(COD)](2) (14) was obtained by reaction of (S)-BBPBINAP (7) with 1 equiv of [Ir(2)Cl(2)(COD)(2)] (COD = cyclooctadiene). The complexes were fully characterized including X-ray structural studies of 8, 9, and 13, and preliminary studies on their catalytic activity were performed.     

Comparison of structure and reactivity of phosphine-amido and hemilabile phosphine-amine chelates of rhodium

A series of mono- and binuclear rhodium(I) complexes bearing ortho-phosphinoanilido and ortho-phosphinoaniline ligands has been synthesized. Reactions of the protic monophosphinoanilines, Ph(2)PAr or PhPAr(2) (Ar = o-C(6)H(4)NHMe), with 0.5 equiv of [Rh(μ-OMe)(COD)](2) result in the formation of the neutral amido complexes, [Rh(COD)(P,N-Ph(2)PAr(-))] or [Rh(COD)(P,N-PhP(Ar(-))Ar)] (Ar(-) = o-C(6)H(4)NMe(-)), respectively, through stoichiometrically controlled deprotonation of an amine by the internal methoxide ion. Similarly, the binuclear complex, [Rh(2)(COD)(2)(μ-P,N,P',N'-mapm(2-))] (mapm(2-) = Ar(Ar(-))PCH(2)P(Ar(-))Ar), can be prepared by reaction of the protic diphosphinoaniline, mapm (Ar(2)PCH(2)PAr(2)), with 1 equiv of [Rh(μ-OMe)(COD)](2). An analogous series of hemilabile phosphine-amine compounds can be generated by reactions of monophosphinoanilines, Ph(2)PAr' or PhPAr'(2) (Ar' = o-C(6)H(4)NMe(2)), with 1 equiv of [Rh(NBD)(2)][BF(4)] to generate [Rh(NBD)(P,N-Ph(2)PAr')][BF(4)] or [Rh(NBD)(P,N-PhPAr'(2))][BF(4)], respectively, or by reactions of diphosphinoanilines, mapm or dmapm (Ar'(2)PCH(2)PAr'(2)), with 2 equiv of the rhodium precursor to generate [Rh(2)(NBD)(2)(μ-P,N,P',N'-mapm)][BF(4)](2) or [Rh(2)(NBD)(2)(μ-P,N,P',N'-dmapm)][BF(4)](2), respectively. Displacement of the diolefin from [Rh(COD)(P,N-Ph(2)PAr(-))] by 1,2-bis(diphenylphosphino)ethane (dppe) yields [Rh(P,P'-dppe)(P,N-Ph(2)PAr(-))] which, while unreactive to H(2), reacts readily and irreversibly with oxygen to form the peroxo complex, [RhO(2)(P,P'-dppe)(P,N-Ph(2)PAr(-))], and with iodomethane to yield [RhI(CH(3))(P,P'-dppe)(P,N-Ph(2)PAr(-))]. Hemilabile phosphine-amine compounds can also be prepared by reactions of [Rh(P,P'-dppe)(P,N-Ph(2)PAr(-))] with Me(3)OBF(4) or HBF(4)·Et(2)O, resulting in (thermodynamic) additions at nitrogen to form [Rh(P,P'-dppe)(P,N-Ph(2)PAr')][BF(4)] or [Rh(P,P'-dppe)(P,N-Ph(2)PAr)][BF(4)], respectively. The nonlabile phosphine-amido and hemilabile phosphine-amine complexes were tested as catalysts for the silylation of styrene. The amido species do not require the use of solvents in reaction media, can be easily removed from product mixtures by protonation, and appear to be more active than their hemilabile, cationic congeners. Reactions catalyzed by either amido or amine complexes favor dehydrogenative silylation in the presence of excess olefin, showing modest selectivities for a single vinylsilane product. The binuclear complexes, which were prepared in an effort to explore possible catalytic enhancements of reactivity due to metal-metal cooperativity, are in fact somewhat less active than mononuclear species, discounting this possibility.     

Dicarboxylate rhodium complexes with diolefins and carbon monoxide

Dinuclear rhodium complexes of the type [Rh₂(C₂O₄)(diolefin)₂] (diolefin)₂  1,5-cyclooctadiene, 2,5-norbornadiene and tetrafluorobenzobarrelene) with bridging oxalate ligands have been obtained by reaction of [Rh(acac)(diolefin)] with oxalic acid (2: 1 mol ratio). The use of a 1 : 1 molar ratio affords [Rh(HC₂O₄)(COD)], that reacts with [Ir(acac)(COD)] yielding the heterodinuclear [(COD)Rh(C₂O₄)Ir(COD)] complex. Treatment of [Rh₂(C₂O₄)(diolefin)₂] complexes with phenanthroline type ligands leads to ionic complexes of formula [Rh(diolefin) (phen)][Rh(C₂O₄)(diolefin)]. Bubbling of carbon monoxide through solutions of the diolefin complexes leads to the formation of carbonylrhodium species of formula [Rh₂(C₂O₄)(CO)₂L₂] (L = CO, PPh₃t-BuNC) or [Rh(CO)₂(phen)] - [Rh(C₂O₄)(CO)₂]. Other related malonate complexes are also described.     

Early-late heterobimetallic alkoxides as model systems for late-transition-metal catalysts supported on titania

Titanium complexes with chelating alkoxide ligands [TiCp*(O(2)Bz)(OBzOH)] (1) and [TiCp*(Me)((OCH(2))(2)Py)] (2) were synthesised by reaction of [TiCp*Me(3)] (Cp*=eta(5)-C(5)Me(5)) with 2-hydroxybenzyl alcohol ((HO)(2)Bz) and 2,6-pyridinedimethanol ((HOCH(2))(2)Py), respectively. Complex 1 reacts with [(M(mu-OH)(cod))(2)] (M=Rh, Ir) to yield the early-late heterobimetallic complexes [TiCp*(O(2)Bz)(2)M(cod)] [M=Rh (3), Ir (4)]. Carbon monoxide readily replaces the COD ligand in 3 to give the rhodium dicarbonyl derivative [TiCp*(O(2)Bz)(2)Rh(CO)(2)] (5). Compound 2 reacts with [(M(mu-OH)(cod))(2)] (M=Rh, Ir) with protonolysis of a Tibond;Me bond to give [TiCp*((OCH(2))(2)Py)(mu-O)M(cod)] [M=Rh (6), Ir (7)]. The molecular structures of complexes 3, 5 and 7 were established by single-crystal X-ray diffraction studies.     

Isolation of [Rh(diolefin)X2]- species and their reactions with P- or N-donor ligands,tin(II) halides and carbon monoxide

Anionic [Rh(diolefin)X₂]⁻ species (X = Cl, Br) have been prepared and their reactions studied. The reactions with monodentate ligands led to neutral tetracoordinated complexes, and with N-donor bidentate ligands (Rh : LL = 2 : 1) gave Rh(X)(diolefin)(LL), [Rh(diolefin)(LL)]⁺[Rh(diolefin)X₂]⁻, or [Rh(diolefin)(LL)]X compounds, depending on the nature of LL or X. Reactions with carbon monoxide involved diolefin displacement. A trichlorostannato complex was obtained from the [Rh(COD)Cl₂]⁻ species. Reactions of [Rh(COD)Br]₂ with bidentate N-donor ligands were also studied.     

Cationic complexes of rhodium(I) with phenanthroline type ligands

Summary Complexes [Rh(COD)(L-L)]ClO₄ are prepared by reaction of [Rh(COD)₂]ClO₄ with the appropriate ligand L-L (4,7-Ph₂Phen, 2,9-Me₂-4,7-Ph₂Phen, 2,9-Me₂Phen or 5,6-Me₂Phen). Treatment of these complexes with carbon monoxide gives [Rh(CO)₂(L-L)]ClO₄. When the carbonylation reaction is performed in the presence of P(4-RC₆H₄)₃, pentacoordinate complexes [Rh(CO)(L-L){P(4-RC₆-H₄)}_{3 2}]ClO₄ (R=Me, H, F or Cl) are formed. The use of [Rh(COD)(L-L)]ClO₄ as homogeneous hydroformylation catalyst precursors was studied (50 atm, 80°C). Under these conditions no hydrogenation of the olefin or of the aldehydes is observed, but isomerisation reactions are significant.