Synthesis of the Trans and Cis Higher Sugar Allylic Alcohols—Direct Precursors of Dodecoses

Abstract

Reaction of 6,7-dideoxy-l,2:3,4-di-O-isopropylidene-α-D-galacto-hept-6-ynopyranose (3) with 3-O-benzyl-l,2-O-sopropylidene-α-D-xylo-pentodiulose (4) afforded two diastereo-isomeric propargylic alcohols: 5a (n-glycero, R) and 5b (L-glycero, S) in 70% yield and in the 33:67 ratio. Hydrogenalion of 5a and 5b over Pd/BaSO₄ gave cis-allylic alcohols 6a and 6b. Semireduction of the triple bond in 3 with tri-n-butyltin hydride afforded trans-olefin 7 which reacted with 4 yielding two diastereoisomeric trans-allylic alcohols: 8a (D-glycero, R) and 8b (L-glycero, S) in a 74% yield and a 72:28 ratio.     

4-Thiazolidines,derivatives and analogs

Heating thiazan-2, 4-dione (I) with P₂S₅ in xylene or toluene gives a hitherto unknown isomer of propiorhodanine (II), 4-thione-1, 3-thiazan-2-one (III), with an active thione group and more acidic properties than II. Reaction of I with P₂S₅ in dioxane gave 2, 4-dithionethiazane, (IV) in high yield, this being the most convenient method of preparing IV.     

Three new copper(II) halides with simple pyridine alcohols

Three Cu(II) halido complexes of 3-pyridinepropanol (3-pyprop), 2-pyridineethanol (2-pyet), and 2-pyridinemethanol (2-pymet) have been prepared and investigation of their crystal structures undertaken. All the reported products contain simple pyridine alcohols as neutral ligands. Cu(3-pyprop)₂Br₂, 1, exhibits square-planar coordination geometry with the axial sites involved in weak bridging contact with the neighboring units to form infinite chains. Reaction of CuBr₂ with 2-pyet leads to an ionic complex [Cu(2-pyet)₂Br]Br, 2, with distorted square-pyramidal coordination environment: the Cu center in the cation is surrounded by two 2-pyet ligands, coordinated in chelating manner, and a bromide. Reaction of CuCl₂ with 2-pymet resulted in the formation of a dinuclear ionic complex Cu₂(2-pymet)₄Cl₂]Cl₂·2H₂O, 3. The centrosymmetric cation consisted of two Cu ions doubly bridged by chlorides and coordinated by chelating 2-pymet ligands. The positive charge is balanced by free chlorides involved in hydrogen bonds with the lattice water molecules.     

Alkoxy-1,3,5-triazapentadien(e/ato) copper(II) complexes: template formation and applications for the preparation of pyrimidines and as catalysts for oxidation of alcohols to carbonyl products

Template combination of copper acetate (Cu(AcO)₂?H₂O) with sodium dicyanamide (NaN(C≡N)₂, 2 equiv) or cyanoguanidine (N≡CNHC(=NH)NH₂, 2 equiv) and an alcohol ROH (used also as solvent) leads to the neutral copper(II)–(2,4‐alkoxy‐1,3,5‐triazapentadienato) complexes [Cu{NH?C(OR)NC(OR)?NH}₂] (R=Me ( 1 ), Et ( 2 ), nPr ( 3 ), iPr ( 4 ), CH₂CH₂OCH₃ ( 5 )) or cationic copper(II)–(2‐alkoxy‐4‐amino‐1,3,5‐triazapentadiene) complexes [Cu{NH?C(OR)NHC(NH₂)?NH}₂](AcO)₂ (R=Me ( 6 ), Et ( 7 ), nPr ( 8 ), nBu ( 9 ), CH₂CH₂OCH₃ ( 10 )), respectively. Several intermediates of this reaction were isolated and a pathway was proposed. The deprotonation of 6 – 10 with NaOH allows their transformation to the corresponding neutral triazapentadienates [Cu{NH?C(OR)NC(NH₂)?NH}₂] 11 – 15 . Reaction of 11 , 12 or 15 with acetyl acetone (MeC(?O)CH₂C(?O)Me) leads to liberation of the corresponding pyrimidines NC(Me)CHC(Me)NC NHC(?NH)OR, whereas the same treatment of the cationic complexes 6 , 7 or 10 allows the corresponding metal‐free triazapentadiene salts {NH₂C(OR)?NC(NH₂)?NH₂}(OAc) to be isolated. The alkoxy‐1,3,5‐triazapentadiene/ato copper(II) complexes have been applied as efficient catalysts for the TEMPO radical‐mediated mild aerobic oxidation of alcohols to the corresponding aldehydes (molar yields of aldehydes of up to 100 % with >99 % selectivity) and for the solvent‐free microwave‐assisted synthesis of ketones from secondary alcohols with tert‐butylhydroperoxide as oxidant (yields of up to 97 %, turnover numbers of up to 485 and turnover frequencies of up to 1170 h^?1).     

Effective catalytic oxidation of alcohols and alkenes with monomeric versus dimeric manganese(II) catalysts and t‐BuOOH

Two new Mn(II) complexes, [Mn(C₆H₅COO)(H₂O)(phen)₂](ClO₄)(CH₃OH) ( 1 ) and [Mn₂(μ‐C₆H₅COO)₂(bipy)₄]?2(ClO₄) ( 2 ) (phen = 1,10‐phenanthroline; bipy = 2,2′‐bipyridine), were synthesized and characterized using UV–visible and infrared spectroscopies and single‐crystal X‐ray diffraction analyses. Complexes 1 and 2 have six‐coordinate octahedral geometry around the Mn(II) centre. Complex 1 is a monomer and consists of a deprotonated monodentate benzoate ligand together with two neutral bidentate amine ligands (phen) and a water molecule. Complex 2 has a dinuclear structure in which two Mn(II) ions share two carboxylate groups, adopting a two‐atom bridging mode, and two chelated bipy ligands. Both complexes catalyse the oxidation of alcohols and alkenes in a homogeneous catalytic system consisting of the Mn(II) complex and tert‐butyl hydroperoxide (TBHP) in acetonitrile. The system yields good to quantitative conversions of various alkenes and alcohols, such as styrene, ethylbenzene and cyclohexene to their corresponding ketones, and primary alcohols and 1‐octanol, 1‐heptanol, cyclohexanol, benzyl alcohols and cinnamyl alcohol to their corresponding aldehydes and carboxylic acids. Complexes 1 and 2 exhibit very high activity in the oxidation of cyclohexene to cyclohexanone (ca 80% selectivity) as the main product (ca 94% conversion in 1 h) and of cinnamyl alcohol to cinnamaldehyde (ca 64% selectivity) as the main product (ca 100% conversion in 0.5 h) with TBHP at 70°C in acetonitrile. In addition, optimum reaction conditions were also determined for benzyl alcohol with complexes 1 and 2 and TBHP. Copyright © 2016 John Wiley & Sons, Ltd.     

Pyrans,their analogs,and related compounds

Reaction of 4, 4-dichloroflavine (I) with sulfurylchloride affords 2, 3, 3, 4, 4-pentachloroflavan (II). Hydrolysis of II gives 2-hydroxy-3, 3-dichloro-4-flavanone (III), while alcoholysis with aqueous alcohols yields 2-alkoxy-3,3-dichloro-4-flavanones (IVa, b). Treatment of III with SOCl₂ gives 2,3,3-trlchloro-4-flavanone (V), which with caustic alkali or sodium ethoxide is converted into o-(1-phenyl-2, 2-dichlorovinyloxy)benzoic acid (VIc) or its ethyl ester (VIb), respectively.For Part XLII, see [7].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1167–1170, September, 1970.     

New silicon-containing heterocyclic rings derived from 1, 3-bis(methyldichlorosilyl)propane

Reaction of 1,3-bis(methyldichlorosilyl)propane with alcohols gives (methylalkoxychlorosilyl)propanes. Hydrolysis of the latter with the calculated amount of water in the presence of a HCl acceptor gives 2, 6-dimethyl-2,6-dialkoxy-1-oxa-2,6-disilacyclohexanes. Hydrolysis of 1,3-bis(methyl-dichlorosilyl)propane and 1,3-bis(methylalkoxy-chlorosilyl)propane gives a tricyclic carbocyclosiloxane. A study is made of the reactions of 2, 6-dimethyl-2, 6-dialkoxy-1-oxa-2, 6-disilacyclohexane with alcohols, triethylsilanol, triethylchlorosilane, and C₆H₅MgBr.     

Synthesis of bis(tetramethylstibonium)tetracyclopentadienylstannate a novel type of organotin(II) compound

Reaction of dicyclopentadienyltin(II) with pentamethylantimony gives [Me₄Sb]₂⁺[(C₅H₅)₄Sn]^2?, the first example of an anionic organotin(II) species.     

Reactions of 3-nitro-1,2,4-triazoles with alkylating agents. 6*. Alkylation of a neutral heterocycle by alcohols in acid media*

Reaction of 3-nitro-1,2,4-triazole and 5-methyl-3-nitro-1,2,4-triazole with secondary and tertiary alcohols in conc. H₂SO₄ takes place at the N(2) atom. Alkylation by 2-propanol occurs regioselectively to form the 1-isopropyl-3-nitro-and 1-isopropyl-3-methyl-5-nitro-1,2,4-triazoles. As a consequence of isomerization the alkylation using cyclohexyl or tert-butyl alcohols gives respectively a mixture of regioisomers substituted at atom N(1) (1-cyclohexyl-3-nitro-and 1-cyclohexyl-5-methyl-3-nitro-1,2,4-triazoles) and at atom N(2) (5-nitro-1-cyclohexyl-and 1-cyclohexyl-3-methyl-5-nitro-1,2,4-triazoles) and, in the second case, to 1-tert-butyl-3-nitro-1,2,4-triazole. * For Communication 5 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1680–1687, November, 2008.     

Synthesis and Some Reactions of Quinoxalinecarboazides

Chlorination of ethyl(quinoxalin‐2(1H)one)‐3‐carboxylate 1 gave ethyl (2‐chloroquinoxaline)‐3‐carboxylate 2 ;thionation of 1 by P₂S₅ or 2 by thiourea yielded the same product 3 . Reaction of chloro compound 2 or thiocompound 3 with hydrazine hydrate gave pyrazolylquinoxaline 4 . The reaction of ester 1 with thiourea or hydrazine hydrate afforded pyrimido quinoxaline 5 or carbohydrazide 6 ; the reaction of 6 with carbon disulfide in basic medium followed by alkylation afforded oxadiazoloquinoxaline derivatives 7, 8a,b . Carboazide 9 was produced by reaction of 5 with nitrous acid. Compound 9 on heating in an inert solvent, with or without amines, in alcohols or hydrolysis in H₂O undergoes Curtius rearrangments to yield 10‐13 . Reaction of 13 with thiosemicarbazide gave triazoloquinoxaline 14 which on reaction with alkylhalides or hydrazine hydrate yielded 15a‐c while hydrolysis of 13 gave 3‐aminoquinoxalinone 16 which was used as an intermediate to produce 17‐20 .     

Oxidation of Benzoins to Benzils with Chromium Trioxide Under Viscous Conditions

Reaction of chiral allylic cyclic carbonates with Grignards reagent in the presence of NiCl₂(dppe) as a catalyst afforded the alkylated (E)-allylic alcohols with high regio- and diastereoselectivity.     

1,4,7-Trithiacyclononane as a Tridentate Ligand for Complexation of Heavy-Metal Ions: Synthesis and Complexation Studies of Mesocyclic and Macrocyclic Polythioethers IV

Bis octahedral complexes of 1,4,7-trithiacyclononane (9-ane-S₃) with Group 12 metal ions Zn(II), Cd(II), and Hg(II), as well as Pb(II), have been prepared. Two equivalents of 9-ane-S₃ react with Zn(BF₄)₂·6H₂O, Cd(ClO₄)₂·6H₂O, Hg(ClO₄)₂·3H₂O, and Pb(ClO₄)₂. 3H₂O, respectively, to give stable crystalline complexes of the formula [M(9-ane-S₃)₂]²+ 2X⁻. Single-crystal X-ray structures of the zinc and mercury complexes have been determined. The zinc complex crystallizes in the orthorhombic space group Pbca with four molecules per unit cell (a = 9.219(3) Å, b = 15.400(5) Å, and c = 19.965(10)Å; R = 7.6%) whereas the mercury complex crystallizes in the monoclinic space group P2₁/c with two molecules per unit cell (a = 10.400(3) Å, b = 15.190(4) Å, c = 9.533(3) Å, and p = 99.09(3)°; R = 5.2%). In each structure, the metal atom is located on a crystallographic center of inversion and is octahedrally surrounded by six sulfur atoms provided by the two facially coordinating tridentate ligands. Reaction of 9-ane-S₃ with RuCl₃·xH₂O displaces chloride ions with concomitant reduction of Ru(III) to Ru(II), giving the octahedral thioether complex, [Ru(9-ane-S₃)₂]Cl₂·4H₂O. Reaction of the ligand with RhCl₃, on the other hand, gives (9-ane-S₃)RhCl₃. A single-crystal X-ray structure determination has been done on the Ru(II) complex (triclinic space group P 1 ̅; a = 7.652(1) Å, b = 8.946(1) Å, c = 9.042(1) Å, α = 93.43(1)°, β = 103.43(1)°, and γ = 107.79(1)°; R = 2.8%) and this complex is also octahedral with the metal center at an inversion center.     

On the Reactivity of Lanthanide Iodides LnIx (x < 3) Formed in the Reactions of Lanthanide Metals with Iodine

The reduced lanthanide iodides of the composition LnI_x (Ln = Sc, Y, La, Ce, Pr, Gd, Ho, and Er; x < 3) were obtained by the reaction of an excess of the appropriate metal with iodine at high temperatures. The diamagnetism of the Sc, Y, and La derivatives indicates the trivalent state of the metals in these products. In contrast to the diiodides of Nd(II), Dy(II), and Tm(II), the isolated solids do not dissolve in THF, DME, or liquid ammonia. Despite of their insolubility in THF, all these products readily react in this medium with phenol or alcohols to give the corresponding phenoxy‐ or alkoxylanthanide diiodides ROLnI₂(THF)_x (R = Ph, i‐C₃H₇, t‐Bu; x = 2, 3, or 5) in yields up to 55 %. Their interactions with cyclopentadiene in THF afford the complexes CpLnI₂(THF)₃ with yields up to 60 %. From the reaction of LaI_x with 2, 2'‐bipyridine (bipy), the complex LaI₂(bipy)₂(THF)₂ was isolated. Triphenylcarbinol, stilbene, naphthalene, and anthracene are inert towards the obtained substances.     

Electronic ground state of iron in octamethyltetrabenzporphyriniron(II), a new square planar ferrous porphyrin

Reaction of iron powder with 1,3,4,7-tetramethylisoindole at 350° affords the square planar complex octamethyl-tetrabenzporphyriniron(II), whose magnetic moment indicates a spin quintet ground state. Mössbauer measurements at 4.2°K in an applied magnetic field of 50 kG show that the electric field gradient at iron is positive and axially symmetric, consistent with a ⁵B_2g ground term. The bistetrahydrofuran adduct is also high spin, whereas the bispyridine adduct is diamagnetic with ¹A_1g ground state. Comparisons are made with data for the related tetraphenylporphiniron(II) and phthalocyanineiron(II) derivatives.     

Réactivité des complexes (η5-cyclohexadiényl)Mn(CO)3 substitués par des groupes électroattracteurs vis-à-vis d'hydrures

Reactivity of electron withdrawing group-substituted (η⁵-cyclohexadienyl)Mn(CO)₃ complexes toward hydrides. Reaction of hydrides with (η⁵-ketocyclohexadienyl)Mn(CO)₃ complexes yielded the corresponding alcohols as major products but also cyclohexadienes due to the addition of hydride to the C2 carbon of the η⁵ π ligand. This unexpected regioselectivity has been established by different labelling experiments and a plausible mechanism has been suggested. The same reaction has been studied in the case of a (η⁵-chlorocyclohexadienyl)Mn(CO)₃ complex.     

Polymer complexes. LXXI. Spectroscopic studies,thermal properties,DNA binding and antimicrobial activity of polymer complexes

Polymer complexes of Co(II), Ni(II), Mn(II), Cr(III) and Cd(II) were prepared by the reaction of 3‐allyl‐5‐[(4‐nitrophenylazo)]‐2‐thioxothiazolidine‐4‐one (HL) with metal ions. The structure of polymer complexes was characterized by elemental analysis, IR, UV–Vis spectra, X‐ray diffraction analysis, magnetic susceptibility, conductivity measurements and thermal analysis. Reaction of HL with Co(II), Ni(II), Mn(II), Cr(III) and Cd(II) ions (acetate or chloride) give polymer complexes ( 1–5 ) with general stoichiometric [M(L)(O₂CCH₃)(H₂O)₂]_n (where L = anionic of HL and M = Co(II) (1) or Ni(II) (2) ), [Mn(HL)₂(OCOCH₃)₂]_n (3) , [Cr(L)₂(Cl)(H₂O)]_n (4) and [Cd(HL)(O₂CCH₃)₂]_n (5) . The value of HOMO–LUMO energy gap (ΔE) for forms (A‐C) of monomer (HL) is 2.529, 2.296 and 2.235 eV, respectively. According to ΔE value, compound has minimum ΔE is the more stable, so keto hydrazone form (C) is more stable than the other forms (azo keto form (A), azo enol form (B)). The interaction between HL, polymer complexes of Co(II), Ni(II), Mn(II), Cr(III) and Cd(II) with Calf thymus DNA showed hypochromism effect. The HL and its polymer complexes were tested against some bacterial and fungal species. The results showed that the Cr(III) polymer complex (4) has more antibacterial activity than HL and polymer complexes (1–3 and 5) against Bacillus subtilis, Staphylococcus aureus and Salmonella typhimurium.     

Synthesis, structure, and reactions of the first homoleptic lithium-arsenic compound, [Li(μ-AsR2)]3 (R = CH(SiMe3)2)

Reaction of Li with AsClR₂ (R = CH(SiMe₃)₂) affords [Li(μ-AsR₂]₃ (I), the first structurally characterised dialkylarsenide, which in OEt₂ at 25°C yields AsHR₂, AsMeR₂, AsHR₂, or A^.sR₂ (II) with HCl, MeCl, Bu^tCl, or SnCl₂, respectively; upon removal of solvent, II furnishes As₂R₄ (III), which readily dissociates into II: the As₃Li₃ ring of I has a boat conformation and the average Li---As bond distance is 2.60(4) Å.     

Coordination properties of 4(5)-hydroxymethylimidazole and 4(5)-hydroxymethyl-5(4)-methylimidazole towards cobalt(II) ions

Two new complexes of imidazole alcohols, 4-hydroxymethylimidazole (4-CH₂OHim) and 4-hydroxymethyl-5-methylimidazole (4-CH₂OH-5-CH₃im), with cobalt(II) of formula [CoL₂(H₂O)₂](NO₃)₂ were obtained. These compounds were described through single X-ray diffraction studies, spectroscopic (Ir. Far-IR, UV-Vis-NIR) and magnetic measurements. In the present complexes imidazole ligands are bidentate coordinating the heterocyclic ring through pyridine-like nitrogen and the oxygen atom of the hydroxymethyl group (chromophore CoN₂O₄). The shape of Co(II) coordination polyhedra is that of a distorted octahedron, with the equatorial plane defined by the 4-CH₂OHim (or 4-CH₂OH-5-CH₃im) bidentate ligands and two water molecules occupying axial positions (i.e. trans to each other). Formation of successive cobalt(II) complexes with 4-CH₂OH-5-CH₃im in aqueous solution was followed quantitatively by potentiometry.     

Highly regio- and stereocontrolled SN2′ reactions of gem-difluorinated vinyloxiranes with monoalkylcopper reagents

Reaction of gem-difluorinated vinyloxiranes with RCu(X)Li allowed us to introduce the R group regioselectively at the fluorine-attached terminal carbon atom in an S_N2′ manner to afford (E)-allylic alcohols exclusively, while homoallylic alcohols with anti stereochemical relationship were found to be obtained selectively from higher-ordered cuprates derived from CuCl and RMgBr in a ratio of 1:3.     

Transfer hydrogenation of ketones catalyzed by nickel complexes bearing an NHC [CNN] pincer ligand

Four NHC [CNN] pincer nickel (II) complexes, [^iPrCNN (CH₂)₄‐Ni‐Br] ( 5a ), [^nBuCNN (CH₂)₄‐Ni‐Br] ( 5b ), [^iPrCNN (Me)₂‐Ni‐Br] ( 6a ) and [^nBuCNN (Me)₂‐Ni‐Br] ( 6b ), bearing unsymmetrical [C (carbene)N (amino)N (amine)] ligands were synthesized by the reactions of [CNN] pincer ligand precursors 4 with Ni (DME)Cl₂ in the presence of Et₃N. Complexes 5a and 5b are new and were completely characterized. The transfer hydrogenation of ketones catalyzed by the four pincer nickel complexes were explored. Complexes 5a and 6a have better catalytic activity than 5b and 6b . With a combination of NaO^tBu/ⁱPrOH/80 °C and 2% catalyst loading of 5a , 77–98% yields of aromatic alcohols could be obtained.