Cross-coupling of E,E-1,4-diiodobuta-1,3-diene with nucleophiles catalyzed by Pd or Ni complexes: a new route to functionalized dienes

E,E-1,4-Diiodobuta-1,3-diene can enter into cross-coupling reactions with carbon- or other element-centered nucleophiles in the presence of Pd or Ni complexes as catalysts. Convenient procedures were developed for the stereoselective synthesis of E,E-1,4-dialkenylbuta-1,3-dienes, dienyl-1,4-bisphosphonates, E,E-1,4-bis(diphenylphosphino)buta-1,3-diene, E,E-1,4-diphenylbuta-1,3-diene, and E,E-1,4-bis(thiophenyl)buta-1,3-diene.     

Diazo reactions with unsaturated compounds: XIII. Reactions of p-(buta-1,3-dien-1-ylsulfonyl)benzenesulfonamide with arenediazonium chlorides, 1-aryl-3,3-dimethyltriaz-1-enes, and arenediazonium tetrachlorocuprates(II)

p-(Buta-1,3-dien-1-ylsulfonyl)benzenesulfonamide reacted with arenediazonium chlorides, 1-aryl-3,3-dimethyltriaz-1-enes, and arenediazonium tetrachlorocuprates(II) in aqueous acetone in the presence of copper(II) chloride to give the corresponding p-(4-aryl-3-chlorobut-1-en-1-ylsulfonyl)benzenesulfonamides.     

Diazo reactions with unsaturated compounds: XI. Reactions of benzene-, p-methylbenzene-, and p-methoxybenzenesulfonyl-1,3-butadienes with arenediazonium chlorides and 1-aryl-3,3-dimethyl-1-triazenes

1-(p-Methylbenzene)-and 1-(p-methoxybenzenesulfonyl)-1,3-butadienes in aqueous acetone in the presence of copper(I) or copper(II) chlorides react with arenediazonium chlorides and 1-aryl-3,3-dimethyl-1-triazenes to form 1-(p-methylbenzene)-and 1-(p-methoxybenzenesulfonyl)-4-aryl-3-chloro-1-butenes, respectively. 1-(Benzenesulfonyl)-1,3-butadiene undergoes tarring under the same conditions.     

GeCl<Subscript>2</Subscript> cycloaddition reactions to unsaturated organic compounds taking ethylene,buta-1,3-diene,and hexa-1,3,5-triene as examples: a quantum chemical study

The cycloaddition reactions of dichlorogermylene GeCl₂ to ethylene, buta-1,3-diene, and hexa-1,3,5-triene were studied within the framework of the density functional theory (PBE and B3LYP density functionals) and by the ab initio CBS-QB3 method. The energy characteristics of the reaction of GeCl₂ with ethylene were refined and non-empirical quantum chemical calculations of reaction pathways in the GeCl₂ + buta-1,3-diene and GeCl₂ + hexa-1,3,5-triene systems were carried out for the first time. It was shown that the [2+1] cycloaddition reactions are kinetically hindered and thermodynamically unfavorable, while the [4+1] and [6+1] cycloaddition reactions are characterized by low barriers and result in thermodynamically favorable products. For the [4+1] cycloaddition to buta-1,3-diene and [6+1] cycloaddition to hexa-1,3,5-triene, the most energetically favorable reaction pathways involve a suprafacial and antarafacial approach of reactants, respectively.     

Diazo Reactions with Unsaturated Compounds: VII. Vinyl p-Methylphenyl and Vinyl p-Nitrophenyl Ethers in the Meerwein Reaction

Vinyl p-methylphenyl ether in aqueous acetone at pH 3-4 in the presence of catalytic amounts of copper(II) chloride reacts with arenediazonium chlorides to form arylacetaldehydes. Vinyl p-nitrophenyl ether under the same conditions fails to react with arenediazonium chlorides.     

Diazo Reactions with Unsaturated Compounds: IX. <Emphasis Type="Italic">ortho</Emphasis>-, <Emphasis Type="Italic">meta</Emphasis>-, and <Emphasis Type="Italic">para</Emphasis>-Nitrophenylsulfonyl-1,3-butadienes in Reaction with 1-Aryl-3,3-dimethyl-1-triazenes

1-(m-Nitrophenylsulfonyl)- and 1-(p-nitrophenylsulfonyl)-1,3-butadienes in aqueous acetone in the presence of HCl and copper(I) or copper(II) chloride react with 1-aryl-3,3-dimethyl-1-triaenes to form 1-(m-nitrophenylsulfonyl)- and 1-(p-nitrophenylsulfonyl)-4-aryl-3-chloro-1-butenes, respectively. 1-(o-Nitro-phenylsulfonyl)-1,3-butadiene fails to react in similar conditions.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 4, 2005, pp. 619–621.Original Russian Text Copyright © 2005 by Naidan, Smalius.For communication VIII, see [1].     

The structure and dynamic behaviour in solution of the trihydridodienerhenium complexes (Ph3P)2(η-1,3-diene)ReH3

The structure and fluxionality of the trihydridodiene complexes (Ph₃P)₂(η-1,3-<di-ene)ReH₃ have been studied by NMR spectroscopy (η-1-3-diene = buta-1,3-diene, 2-methylbuta-1,3-diene, 2,3-dimethylbuta-1,3-diene, cyclohexa-1,3-diene, penta-1,3-diene, hexa-1,3-diene and hexa-2,4-diene). Several rearrangement processes have been observed; they are, in order of increasing temperature: (a) ligand interchange; (b) reversible migration of a hydride ligand on to the diene ligand, leading to η-allyl species and, in the case of the cyclohexadiene trihydride, degenerate isomerisation of the cyclohexadiene moiety; and (c), in the case of the pentadiene and hexadiene derivatives, isomerisation of the diene ligand.     

Basic hydrolysis of l,4-bis(triphenylphosphonio)buta-1,3-diene dihalides

Basic hydrolysis of 1,4-bis(triphenylphosphonio)buta-1, 3-diene dichloride with 10% NaOH gave isomeric 4-diphenylphosphoryl-4-phenylbut-1(2)-enes and 1-diphenylphosphoryl-1-phe-nylbuta-1, 3-diene, the products of anionotropic migration of a phenyl group from the P atom to the α-position. Hydrolysis with Na₂CO₃ afforded only the diene product. In both cases, triphe-nylphosphine and triphenylphosphine oxide were isolated as secondary products. Dehydro-chlorination of 2-chloro-1,4-bis(triphenylphosphonio)but-2-ene dibromide with triphenylphosphine was proposed as a new convenient route to 1,4-bis(triphenylphosphonio)buta-1,3-diene dibromide.     

A novel cyclization reaction between 2,3-bis(trimethylsilyl)buta-1,3-diene and acyl chlorides with straightforward formation of polysubstituted furans

A novel cyclization process of 2,3-bis(trimethylsilyl)buta-1,3-diene with various acyl chlorides in the presence of aluminium trichloride affords 2,5-disubstituted or 2,3,5-trisubstituted furans in short reaction time; a subsequent acylation process of the furan ring occurs if the reaction time is prolonged.     

Synthesis and Structure of 2,3-Bis(5-tert-butyl-2-methoxyphenyl)buta-1,3-diene by Bromine Elimination of (Z)-1,4-Dibromo-2,3-bis(5-tert-butyl-2-methoxyphenyl)-2-butene

2,3-Bis(5-tert-butyl-2-methoxyphenyl)buta-1,3-diene was prepared by bromination of (Z)- and (E)-2,3-bis(5-tert-butyl-2-methoxyphenyl)-2-butene followed by treatment with zinc powder in a mixture of CH₂Cl₂ and acetic acid, which was converted to the corresponding o-terphenyl skeleton by the condensation with dimethyl acetylenedicarboxylate followed by oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone.     

Invasion inhibitors of human fibrosarcoma HT 1080 cells from the rhizomes of Zingiber cassumunar: structures of phenylbutanoids, cassumunols

The methanolic extract and its EtOAc-soluble fraction from the rhizomes of Zingiber cassumunar inhibited invasion of human fibrosarcoma HT 1080 cells. From the EtOAc-soluble fraction, eight new phenylbutanoids, cassumunols A-H, were isolated together with 30 known constituents. The structures of new phenylbutanoids were elucidated on the basis of chemical and physicochemical evidence. Principal constituents were examined the inhibitory effects on the invasion of HT 1080 cells. Among them, phlain I and III, (E)-1-(3,4-dimethoxyphenyl)buta-1,3-diene, (E)-1-(2,4,5-trimethoxyphenyl)buta-1,3-diene, and (-)-β-sesquiphellandrene showed anti-invasion effects. Interestingly, (E)-1-(2,4,5-trimethoxyphenyl)buta-1,3-diene [inhibition (%) 46.8 ± 7.2 (p<0.05) at 30 μM] significantly inhibited the invasion, and only a weak cytotoxic effect was observed.     

Heterocyclic Syntheses on the Basis of Arylation Products of Unsaturated Compounds: X. 3-Aryl-2-chloropropanals as Reagents for the Synthesis of 2-Amino-1,3-thiazole Derivatives

Meerwein reaction of arenediazonium chlorides with acrolein gave 3-aryl-2-chloropropanals which were brought into cyclocondensation with thiourea. The resulting 2-amino-5-benzyl-1,3-thiazoles were acylated with carboxylic acid chlorides and phthalic anhydride to afford, respectively, 2-acylamino-5-benzyl-1,3-thiazoles and N-(5-benzyl-1,3-thiazol-2-yl)phthalimides.     

13C,13C coupling constants of conjugated dienes

One bond ¹³C,¹³C- and ¹³C,¹H-coupling constants have been measured for some 1,2-dimethylene-cycloalkanes, as well as for 2,3-dimethylbuta-1,3-diene and methylenecyclobutane. The results for 2,3-dimethylbuta-1,3-diene confirm the findings for buta-1,3-diene, i.e. that J(C-1, C-2) is smaller for the diene than for the correspondingly substituted monoene. No differences have been found between the ¹J(CC) exocyclic coupling constants of the dimethylene and monomethylene cycloalkanes.     

1,3-Dipolar cycloaddition of diazocyclopropane to strained cycloalkenes and conjugated dienes to give spiro(1-pyrazoline-3,1′-cyclopropanes)

Polycyclic spiro(1-pyrazoline-3,1-cyclopropanes) were obtained in 32–70 % yields by the reaction of diazocyclopropane generatedin situ with 2-methyltricyclo[3.2.1.0^2,4]oct-6-ene, spiro[2,4]hepta-4,6-diene dimer, benzvalene, spiro[2,3]hex-1-ene, methyl 1-methylcyclopropene-3-carboxylate, buta-1,3-diene, and 2-methylbuta-1,3-diene.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2199–2202, November, 1995.This study was financially supported by the Russian Foundation for Basic Research (Grant No. 94-03-08902).     

Effect of basic set quality and electron correlation on the scale factors of a harmonic force field

The completely optimized structure and harmonic force field of s-trans-buta-1,3-diene are reported at the MP2/6-31G and MP2/6-31G* levels of computation. Sets of empirical scale factors for the calculated force fields are derived and compared with the corresponding values computed at the RHF/4-31G and RHF/6-31G levels. Changes in the scale factors for this series of force fields are discussed. The vibrational frequencies are also reported for thirteen isotopomers of s-trans-buta-1,3-diene using the MP2/6-31G* force field. Some characteristics of the gauche and cis forms of buta-1,3-diene are also given.     

The catalysis of alkene isomerisation,oligomerisation, and polymerisation by cationic nitrosylrhodium complexes

The complex [Rh(NO)(NCMe)₄][BF₄]₂ catalyses the isomerisation of terminal to internal alkenes, the oligomerisation of branched alkenes such as 2-methylpropene, and the stereospecific polymerisation of buta-1,3-diene to trans-1,4-polybutadiene.     

Computational study of reaction pathways in the course of interaction of deactivated silylenes with buta-1,3-diene

The PESs of systems including deactivated silylenes (SiHHal, SiHal₂, Hal = F, Cl, and 2-silaimidazol-2-ylidene, SiN₂H₂C₂H₂) and buta-1,3-diene have been studied using G3(MP2)//B3LYP method. Two major reaction channels, (2 + 1) and (4 + 1) cycloaddition reactions, leading to 2-vinylsiliranes and silacyclopent-3-enes, respectively, as well as [1,3]-sigmatropic rearrangements between 2-vinylsiliranes and the corresponding silacyclopent-3-enes, have been considered in detail. Reactivity of silylenes toward buta-1,3-diene decreases in the following series: SiHHal > SiHal₂ > SiN₂H₂C₂H₂, which is reflected in increase of the reaction barriers for both cycloaddition reactions and in decrease of exothermicity of the formation of the corresponding products. The (4 + 1) cycloaddition is preferable for SiHal₂ and SiN₂H₂C₂H₂ and can compete with (2 + 1) cycloaddition for SiHHal. [1,3]-Sigmatropic rearrangement is important for isomerization of 2-vinylsiliranes to the corresponding silacyclopent-3-enes for all systems studied, except the SiCl₂ system.     

The reactions of trifluoromethyl and trichloromethyl radicals with conjugated and methylene-interrupted dienes and enynes

The photochemical addition of CF₃I to buta-1,3-diene and vinylacetylene in the gas phase gave 1,4-adducts as the main products. In gas phase reactions only products derived from hydrogen abstraction were detected in the CF₃I/penta-1,3-diene system, but the 1,4-adducts again predominated in the liquid phase. CCl₃Br similarly gave a mixture of 1,2- and 1,4-adducts, the latter predominating, on photochemical reaction with penta-1,3-diene. The 1,2-adduct was the main product from the CCl₃Br/pent-1-en-4-yn reaction, but some hydrogen abstraction was observed. The preference shown by conjugated dienes to give 1,4-adducts in the $\text{trans}$- configuration is interpreted in terms of steric factors and the propensity of dienes to adopt the $\text{s}$-$\text{trans}$ conformation.     

Metal atom synthesis ofsyn(1-3-η-but-2-enyl)(η-buta-1,3-diene)(triethylphosphine)cobalt

Summary Cocondensation of buta-1,3-diene with cobalt vapor followed by addition of triethylphosphine gave a new complexsyn-Co(C₄H₇)(C₄H₆)(PEt₃) (1) in 43% yield. The reaction pathway leading to (1) was investigated by matrix isolation i.r. spectroscopy. The monodentate butadiene, which was found as a reaction intermediate in the –196 toca. 0° temperature range, rearranges into a -butenyl or bidentate butadiene. The reaction of (1) with bromoethane gave cycloocta-1,5-diene and 4-vinylcyclohex-1-ene in quantitative yield. Complex (1) catalyzes the cyclotrimerization of phenylacetylene to 1,3,5-triphenylbenzene.     

An ab initio/RRKM study of product branching ratios in the photodissociation of buta-1,2- and -1,3-dienes and but-2-yne at 193 nm

Ab initio G2M(MP2)//B3LYP/6-311G** calculations have been performed to investigate the reaction mechanism of photodissociation of buta-1,2- and -1,3-dienes and but-2-yne after their internal conversion into the vibrationally hot ground electronic state. The detailed study of the potential-energy surface was followed by microcanonical RRKM calculations of energy-dependent rate constants for individual reaction steps (at 193 nm photoexcitation and under collision-free conditions) and by solution of kinetic equations aimed at predicting the product branching ratios. For buta-1,2-diene, the major dissociation channels are found to be the single Cbond;C bond cleavage to form the methyl and propargyl radicals and loss of hydrogen atoms from various positions to produce the but-2-yn-1-yl (p1), buta-1,2-dien-4-yl (p2), and but-1-yn-3-yl (p3) isomers of C(4)H(5). The calculated branching ratio of the CH(3) + C(3)H(3)/C(4)H(5) + H products, 87.9:5.9, is in a good agreement with the recent experimental value of 96:4 (ref. 21) taking into account that a significant amount of the C(4)H(5) product undergoes secondary dissociation to C(4)H(4) + H. The isomerization of buta-1,2-diene to buta-1,3-diene or but-2-yne appears to be slower than its one-step decomposition and plays only a minor role. On the other hand, the buta-1,3-diene-->buta-1,2-diene, buta-1,3-diene-->but-2-yne, and buta-1,3-diene-->cyclobutene rearrangements are significant in the dissociation of buta-1,3-diene, which is shown to be a more complex process. The major reaction products are still CH(3) + C(3)H(3), formed after the isomerization of buta-1,3-diene to buta-1,2-diene, but the contribution of the other radical channels, C(4)H(5) + H and C(2)H(3) + C(2)H(3), as well as two molecular channels, C(2)H(2) + C(2)H(4) and C(4)H(4) + H(2), significantly increases. The overall calculated C(4)H(5) + H/CH(3) + C(3)H(3)/C(2)H(3) + C(2)H(3)/C(4)H(4) + H(2)/C(2)H(2) + C(2)H(4) branching ratio is 24.0:49.6:4.6:6.1:15.2, which agrees with the experimental value of 20:50:8:2:2022 within 5 % margins. For but-2-yne, the one-step decomposition pathways, which include mostly H atom loss to produce p1 and, to a minor extent, molecular hydrogen elimination to yield methylethynylcarbene, play an approximately even role with that of the channels that involve the isomerization of but-2-yne to buta-1,2- or -1,3-dienes. p1 + H are the most important reaction products, with a branching ratio of 56.6 %, followed by CH(3) + C(3)H(3) (23.8 %). The overall C(4)H(5) + H/CH(3) + C(3)H(3)/C(2)H(3) + C(2)H(3)/C(4)H(4) + H(2)/C(2)H(2) + C(2)H(4) branching ratio is predicted as 62.0:23.8:2.5:5.7:5.6. Contrary to buta-1,2- and -1,3-dienes, photodissociation of but-2-yne is expected to produce more hydrogen atoms than methyl radicals. The isomerization mechanisms between various isomers of the C(4)H(6) molecule including buta-1,2- and -1,3-dienes, but-2-yne, 1-methylcyclopropene, dimethylvinylidene, and cyclobutene have been also characterized in detail.