Carbonyl allylations by allylic chlorides utilizing a reduction of tin(IV) iodide to triiodostannate(II) species with iodide sources

Carbonyl allylations by allylic chlorides either with tin(IV) iodide and tetrabutylammonium iodide (TBAI) in dichloromethane or with tin(IV) iodide and sodium iodide in 1,3-dimethylimidazolidin-2-one at room temperature produced the corresponding homoallylic alcohols. The carbonyl allylations probably proceeded via the reduction of tin(IV) iodide to triiodostannate(II) species with iodide sources such as TBAI and NaI, which led to the construction of a tin(IV)-catalytic cycle based on regeneration of tin(IV) iodide via the transmetalation of homoallyloxytriiodotin to homoallyloxytrimethylsilane with iodotrimethylsilane.     

Studies on the reaction of organotin phenoxides with ethyl propiolate catalysed by triethylamine and tin(IV) chloride

Different tributyltin phenoxides react at room temperature with ethyl propiolate in benzene, in the presence of tin(IV) chloride, triethylamine and their mixture to give the derivatives of 3‐phenoxyacrylic acid ethyl ester. Exceptionally, 3‐(2‐hydroxyphenyl)acrylic acid ethyl ester and 3‐(2‐hydroxy‐5‐methylphenyl)acrylic acid ethyl ester have been obtained from the reaction of tributylphenoxytin and tributyl(p‐tolyloxy)tin, respectively catalysed by SnCl₄, and they have been easily hydrolysed to coumarin and 6‐methylcoumarin. Copyright © 2007 John Wiley & Sons, Ltd.     

Interaction of tin (IV) chloride with sulfolane and between tin (IV) chloride and lithium chloride in sulfolane solution

Tin (IV) chloride reacts with sulfolane (S) to form a cis-octahedral adduct SnCl₄·S₂. Solutions of lithium chloride and tin (IV) chloride in sulfolane contain the complex ions SnCl ₅ ^– and SnCl ₆ ^2– at 11 and 21 mole ratios of constituents, respectively. The complexes are characterized by conductimetry and by Mössbauer, IR, and Raman spectroscopy.     

Rhodium-catalyzed carbonyl allylations by allylic alcohols with tin(II) chloride

Rhodium complexes such as [RhCl(cod)]₂, [Rh(cod)₂]BF₄, and [Rh(cod)(CH₃CN)₂]BF₄ function as catalysts for carbonyl allylations by allylic alcohols with 1 equimolar amount of tin(II) chloride to each allylic alcohol and aldehyde in THF at 50 °C to produce the corresponding homoallylic alcohols.     

Graphene oxide‐bound electron‐deficient tin(IV) porphyrin: a highly efficient and selective catalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazane

The catalytic activity of graphene oxide‐bound tetrakis(p ‐aminophenyl)porphyrinatotin(IV) trifluoromethanesulfonate, [Sn^IV(TNH₂PP)(OTf)₂], in the trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) is reported. The prepared catalyst was characterized using inductively coupled plasma analysis, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared and diffuse reflectance UV–visible spectroscopies. This heterogeneous catalyst was used for selective trimethylsilylation of various alcohols and phenols with HMDS in short reaction times and high yields. Also, the catalyst is of high reusability and stability, in that it was recovered several times without loss of its initial activity. The chemoselectivity of this catalytic system in the silylation of primary alcohols in the presence of secondary and tertiary alcohols and also phenols was investigated.     

Synthesis and characterization of intermediate sitting-atop (i-SAT) complexes of free base meso-tetraarylporphyrins and tin(IV) chloride

The reaction of meso-tetraarylporphyrins (H₂T(X)PP) with SnCl₄ affords green intermediate sitting-atop (i-SAT) complexes, [(H₂T(X)PP)SnCl₄]. UV–Vis, ¹H NMR and ¹³C NMR spectral data show that the porphyrin core of the complexes is distorted, thus two nitrogen atoms of the pyrrolenine groups on one side of the porphyrin plane act as electron donors to the tin center of SnCl₄. The intermediate sitting-atop (i-SAT) complex is formed each time during the incorporation of the metal center, where in the intermediate state the pyrrolic protons still remain on the porphyrin.     

Synthesis and Characterization of Dichlorotin(IV)trithiophosphates and Their Adducts with Nitrogen Donor Bases

Abstract

Dichlorotin(IV)trithiophosphates [(RO)P(S)S ₂ ]SnCl ₂ were prepared by the reaction of methanolic solution of SnCl ₄ and dipotassium salt of trithiophosphates in a 1:1 molar ratio and their adducts [(RO)P(S)S ₂ ]SnCl _2.N ₂ C ₁₂ H ₈ and [(RO)P(S)S ₂ ]SnCl _2.N ₂ C ₁₀ H ₈ were prepared by the reaction of methanolic solution of [(RO)P(S)S ₂ ]SnCl ₂ and N-donor bases in a 1:1 molar ratio. These newly synthesised derivatives have been characterized by elemental analysis; molecular weight measurements; and IR, ¹³ C, ³¹ p and ¹¹⁹ Sn NMR spectral studies. Coordination number of four and six was suggested for dichlorotin (IV)trithiophosphates and their adducts with N-donor bases respectively.     

Bis(chlorido)tin(IV)meso-substituted Porphyrins-Characterization and Solubility

Investigation of the solubility behavior of para-substituted (H, Me, t-Bu, n-Bu) meso-tetraarylporphyrins as well as meso-tetraalkylporphyrins (Me, n-Pr, n-Bu) were performed. An increase of solubility in chloroform and benzene is detected according to the higher functionality in para position of the phenyl ring for meso-tetraarylporphyrins or in meso position on meso-tetraalkylporphyrins. Furthermore, the series of bis(chlorido)tin(IV) meso-tetraarylporphyrin and bis(chlorido)tin(IV) meso-tetraalkylporphyrin was investigated via UV/Vis spectroscopy, ¹¹⁹Sn-NMR and single crystal X-ray diffraction.     

Oxidation of ketones by cerium(IV) in presence of iridium(III) chloride

Kinetic data, in iridium(III) chloride catalyzed oxidation of ethyl methyl ketone (EMK) and methyl propyl ketone (MPK) by cerium(IV) perchlorate in aqueous perchloric acid medium, suggest the formation of complex C₁ between cerium(IV) and organic substrate in the first equilibrium step, which in turn gives rise to another complex C₂ with the catalyst. This second complex in the rate-determining step gives rise to the intermediate products. Interestingly IrCl_3, which is considered to be a sluggish catalyst in alkaline media, was found to surpass the catalytic efficiency of even osmium and ruthenium in acidic media. Rate decreases in the beginning at low acid concentrations, but after reaching to a minimum it becomes directly proportional to acid concentrations. Probably on increasing the acid concentrations hydrolyzed species of ceric perchlorate gradually converts into the un-hydrolyzed species, which then accelerates the rate at higher [H⁺], resulting in the observed peculiar effect of hydrogen ions on the rate. Initial concentrations of cerium(IV) and acid determine the extent of reduction of cerium(IV) by water. Order of the reaction shows direct proportionality with respect to the oxidant and ketones at their low concentrations, but tends to become zeroth order at their higher concentrations. Rate of the reaction shows direct proportionality with respect to [IrCl₃] while change in ionic strength of the medium does not affect the reaction velocity. Parameters such as the energy of activation, free energy of activation and entropy data suggest that methyl propyl ketone forms the activated complex more easily compared to ethyl methyl ketone.     

三(邻氟苄基）氯化锡和四(对氟苄基）锡的合成及结构研究

邻氟苄基氯或对氟苄基氯分别与锡反应合成三(邻氟苄基)氯化锡(1)和四(对氟 苄基)锡(2)．经X射线方法测定了新化合物的晶体结构．晶体结构1属单斜晶系，空 间群为P2(1)／n，晶体学参数：a＝0.5896(9)nm,b-1.262(2)nm,c=2.634(4)nm, V=1.959(5)nm^3,Z=4,Dx=1.632g/cm^3,μ（Mo Kα)=14.69cm^-1,F(000)=952, R1=0.0541,wR2=0.1280;晶体结构2属单余晶系，空间群为Cc,晶体学参数：α=1. 0778(6)nm,b=2.3312(14)nm,c=1.0888(7)nm,V=2.460(3)nm^3,Z=4,Dx=1. 499g/cm^2,μ(Mo Kα)=10.82cm^-1,F(000)=1112,R1=0.0302,wR2=0.0590.在化合 物1和2中Sn-C键长分别为0.2136-0.2148和0.2138-0.2180nm,Sn-Cl键长为0.2378 (4)nm,中心锡与亚甲基碳（氯）原子构成畸型四面体。     

Chromatographic behaviour of metal ions on tin(IV) and titanium(IV) antimonate papers

Summary The chromatographic behaviour of 49 metal ions has been studied on papers impregnated with Sn(IV) and Ti(IV) antimonates in aqueous HNO₃ and mixed solvent systems containing dimethyl sulphoxide. Numerous separations have been achieved and the Alberti equation, for Sn(IV) and Ti(IV) antimonate papers, in the modified form: –nloga K⁺=R_M + constant (a K⁺=activity of K⁺), has been verified. The effect of the concentration of impregnating reagents on these papers has been determined and compared with other papers. The effect of pH on R_f, R_i, log R_f and R_M values of metal ions has also been examined in aqueous systems.     

三(3,5-二甲基苄基)氯化锡和四(间氰基苄基)锡的合成、晶体结构和量子化学研究

以3,5-二甲基苄基氯和间氰基苄基氯在适当的溶剂中与锡粉反应,合成了三(3,5-二甲基苄基)氯化锡(1)和四(间氰基苄基)锡(2),经X射线衍射方法测定了化合物的晶体结构。化合物1属单斜晶系,空间群为P21/m,晶体学参数:a=0.584 03(4)nm,b=1.966 37(14)nm,c=0.856 46(5)nm,β=95.138(3),V=0.979 62(11)nm3,Z=2,Dc=1.735 g·cm-3,μ(Mo Kα)=14.53 cm-1,F(000)=524,R1=0.043 7,w R2=0.123 2。化合物2属单斜晶系,空间群为C2/c,晶体学参数:a=1.692 21(12)nm,b=1.167 41(8)nm,c=1.539 41(11)nm,β=116.615(10)°,V=2.718 9(3)nm3,Z=4,Dc=1.424 g·cm-3,μ(Mo Kα)=9.67cm-1,F(000)=1 176,R1=0.017 5,w R2=0.046 1;中心锡原子为畸变四面体构型。对其结构进行量子化学从头计算,探讨了配合物的稳定性、分子轨道能量以及部分前沿分子轨道的组成特征。     

Organometallic complexes with biological molecules. XV. Effects of tributyltin(IV)chloride on enzyme activity,Ca2+, and biomolecule and synthesis in Ciona intestinalis (Urochordata) ovary

Considerable attention has been given in recent years to the possibility that xenobiotics in the environment may affect reproduction in animals. In this study, the relative impact of tributyltin(IV) (TBT) chloride, one of the most toxic environmental pollutants, was investigated using Ciona intestinalis ovary as a model system. The pleiotropic effects of TBT exposure are concentration dependent and include a decrease of ATP levels, lipid content and nucleic acid content and synthesis. In contrast, a marked increase in calcium (Ca²⁺) and glucose content is observed. Furthermore, TBT alters enzymatic activity, inhibiting creatine kinase and stimulating alkaline phosphatase and cholinesterase (at concentrations higher than 10^?5M in sterile sea water solution). The implications of these effects on reproduction and embryonal development are discussed, along with the possibility that they reflect an extreme cellular defence mechanism triggered to avoid deleterious consequences for the survival of the species.Copyright © 2001 John Wiley & Sons, Ltd.     

Untersuchungen über Zinn(IV)-alkoxide. II. Isolierung und Charakterisierung der Verbindung Sn3O(OiBu)10 · 2i-BuOH. Das erste Beispiel für ein partielles Hydrolyseprodukt eines Zinn(IV)-alkoxids

Investigations into Tin(IV) Alkoxides. II. Isolation and Characterization of the Compound Sn₃O(OⁱBu)₁₀₁₀ · 2i-BuOH. The First Example of a Partially Hydrolized Tin(IV) Alkoxide The partial hydrolysis product Sn₃O(OⁱBu)₁₀ · 2i-BuOH was obtained by slow hydrolysis of the reaction product of tin tetrachloride with sodium isobutoxide. The compound forms colourless, moisture sensitive crystals, which easily release the coordinated solvent molecules in dry air. Its crystal and molecular structure has been determinated by single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P1 with a = 1363.5(7), b = 1462.7(10), c = 1637.7(7) pm, α = 95.40(5)°, β = 96.79(4)°, γ = 102.12(5)° and Z = 2. The crystal structure consists of discrete, trimeric molecules with octahedrally coordinated tin atoms which are connected to each other corresponding to the formulation Sn₃(μ₃-O)(μ₂-OⁱBu)₃(O¹Bu)₇ · (i-BuOH)₂ by three isobutoxide groups bridging two metal atoms and a single threefold bridging oxygen atom     

三(3,5-二氟苄基)氯化锡和四(邻氯苄基)锡的合成、晶体结构及量子化学

3,5-二氟苄基氯和邻氯基苄基氯在适当的溶剂中与锡粉反应,合成了三(3,5-二氟苄基)氯化锡(1)和四(邻氯苄基)锡(2),经X射线衍射方法测定了新化合物的晶体结构。化合物1属单斜晶系,空间群为C2/c,晶体学参数:a=1.858 33(11)nm,b=1.140 98(7)nm,c=2.690 06(16)nm,β=109.288(10)°,V=5.383 6(6)nm3,Z=8,Dc=1.532 g·cm~(-3),μ(Mo Kα)=13.61 cm~(-1),F(000)=2 480,R1=0.085 1,wR~2=0.168 1。化合物2属单斜晶系,空间群为P21/m,晶体学参数:a=0.585 54(5)nm,b=1.969 74(18)nm,c=0.857 86(8)nm,β=95.204 0(10)°,V=0.985 34(15)nm3,Z=2,Dc=1.805 g·cm~(-3),μ(Mo Kα)=14.91 cm-1,F(000)=524,R1=0.054 0,wR_2=0.163 9;中心锡原子为畸变四面体构型。对其结构进行量子化学从头计算,探讨了化合物的稳定性、分子轨道能量以及部分前沿分子轨道的组成特征。测定了化合物的热稳定性。     

Tris(2-cyanoethyl)tin(IV) bromide and tris(2-cyanoethyl)tin(IV) iodide,their structure,properties and reactions with adenosine,AMP and ATP

Complexes [Sn(CH₂CH₂CN)₃I] (1) and [SnBr(CH₂CH₂CN)₃] (2) have been obtained by the oxidation reactions of hexakis(2-cyanoethyl)ditin(III) by means of iodine and bromine. The complexes have been characterized by NMR and IR spectroscopy methods and X-ray crystallography. Both compounds consist of zigzag single-strand chains with a bridging 2-cyanoethyl ligand coordinating via the CH₂ group and N atom. The tin atoms are in a distorted trigonal bipyramidal environment with bromo or iodo ligands and a nitrogen atom occupying the axial coordination sites. The Sn(1)–N(3i) distances in complexes 1 and 2 are considerably longer than the tin-equatorial ligand bonds. The molecular and electronic structures and IR spectra of [SnBr(CH₂CH₂CN)₃] mononuclear and [SnBr(CH₂CH₂CN)₃]₂ dinuclear fragments of the complex have been studied by the DFT B3LYP method. The calculated interatomic distances for the entity containing a five-coordinate tin atom agree well with those found crystallographically. The compounds in water solutions form trigonal bipyramidal complexes containing aqua and hydroxo axial ligands. The interaction of these complexes with adenosine, 5′-adenosine monophosphate and 5′-adenosine triphosphate has been investigated.     

Efficient Aromatization of 4,5-Dihydro-3(2H)-Pyridazinones Substituted at 5 Position by Using Anhydrous Copper (II) Chloride

An efficient conversion of 5-substituted-4,5-dihydro-3(2H)-pyridazinones into their corresponding dehydrogenated derivatives was achieved by treatment with anhydrous copper(II) chloride in acetonitrile.     

Synthesis and characterization of tin(IV)/organotin(IV) complexes with 2-benzoylpyridine-N(4)-cyclohexylthiosemicarbazone [HBPCT]: X-ray crystal structure of [SnCl3(BPCT)]

Four new tin(IV)/organotin(IV) complexes, [SnCl₃(BPCT)] (2), [MeSnCl₂(BPCT)] (3), [Me₂SnCl(BPCT)] (4), and [Ph₂SnCl(BPCT)] (5), have been synthesized by the direct reaction of 2-benzoylpyridine-N(4)-cyclohexylthiosemicarbazone [HBPCT, (1)] and stannic chloride/organotin(IV) chloride(s) in absolute methanol under purified nitrogen. HBPCT and its tin(IV)/organotin(IV) complexes (2–5) were characterized by CHN analyses, molar conductivity, UV-Vis, FT-IR, and ¹H NMR spectral studies. In all the complexes, tin(IV) was coordinated via pyridine-N, azomethine-N, and thiolato-S from 1. The molecular structure of 2 has been determined by X-ray single-crystal diffraction analysis. Complex 2 is a monomer and the central tin(IV) is six-coordinate in a distorted octahedral geometry. The crystal system of 2 is monoclinic with space group P121/n1 and the unit cell dimensions are a?=?8.3564(3)?Å, b?=?23.1321(8)?Å, c?=?11.9984(4)?Å.     

Rapid,highly efficient and chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) catalyzed by reusable electron‐deficient tin(IV)porphyrin

In this paper, rapid and highly efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) in the presence of catalytic amounts of high‐valent [Sn^IV(TPP)(OTf)₂] is reported. This catalytic system catalyzes trimethylsilylation of primary, secondary and tertiary alcohols as well as phenols, and the corresponding TMS‐ethers were obtained in high yields and short reaction times at room temperature. It is noteworthy that this method can be used for chemoselective silylation of primary alcohols in the presence of secondary and tertiary alcohols and phenols. The catalyst was reused several times without loss of its catalytic activity. Copyright © 2009 John Wiley & Sons, Ltd.     

Effects of tributyltin(IV) chloride on fertilization of Styela plicata (Ascidiacea: Tunicata): II. Scanning and transmission electron microscopy studies

The morphological aspects of Styela plicata fertilization after treatment with tributyltin(IV) chloride are described by means of scanning and transmission electron microscopy investigations. Alterations have been shown both on female and male gametes; spermatozoa, all the egg envelopes and the mitochondria of the egg cortical cytoplasm are modified in relation to incubation time. As a consequence, the damage to gametes blocks sperm–egg interaction and fertilization does not occur. Copyright © 2003 John Wiley & Sons, Ltd.