Allene Derivatives Research Articles

Allene formation by coupling of propargylic ethers with olefins via β-alkoxide elimination of zirconacycle intermediates

A zirconocene-ethylene complex reacted with propargylic ethers to give allene derivatives in good yields via β-alkoxide elimination. Deuterolysis of the reaction mixture revealed that the final product after elimination still had a zirconium-carbon bond. Coupling of styrene and propargylic ethers was mediated by Cp2ZrBu2 (Negishi reagent) to give phenethyl allene derivatives. β-Alkoxide elimination from zirconacyclopentadienes bearing two α-CH2OMe groups was also observed. One CH2OMe group was easily eliminated. Elimination of the second CH2OMe group was dependent on its structure.

Multiconfiguration linear response approach to the calculation of parity violating potentials in polyatomic molecules

We present a multiconfiguration linear response approach to electroweak quantum chemistry including effects from the parity violating weak nuclear force. Compared to our previous configuration interaction singles-restricted Hartree–Fock (CIS-RHF) approach [A. Bakasov, T. K. Ha, and M. Quack, J. Chem. Phys. 109, 7263 (1998)], the parity violating potential Epv is introduced by the linear response function and by solving the linear response equations in a direct iterative manner. Calculations are carried out within the multiconfiguration linear response approximation (MCLR) and its special cases, the configuration interaction approach (CI) and the random phase approximation (RPA). The systematic approach presented here, provides a systematic check and improvement upon various approximations used in the calculation of Epv. Extensive results are obtained for hydrogen peroxide at the CISDT (CI singles, doubles and triples) and CISDTQ (CI singles, doubles, triples, and quadruples) as well as at the complete active space self-consistent-field–linear response (CASSCF–LR) level. We compare to carlier results at the CIS-RHF level and confirm the order of magnitude increase in Epv reported earlier as compared to the widely used single determinant excitation-restricted Hartree–Fock (SDE-RHF) method. The new approach overcomes previous limitations for calculating Epv with biradicaloid structures such as twisted ethylene, for which numerical results are presented. This allows us to calculate Epv for a similar unsaturated system such as allene derivatives, which may be of experimental interest.

Reactions of Allenyltri-n-butylstannane with Halides of Phosphorus, Arsenic, Antimony, Germanium, Tin, and Boron. Preparation of Propargylic and/or Allenic Derivatives

The reaction of allenyltri-n-butylstannane with a phosphorus or arsenic trihalide and with germanium tetrachloride gave the corresponding propargylic halophosphine, arsine, or germane. When they were heated, the propargylic products partially (P, Ge) or completely (As) rearranged into the corresponding allenyl derivatives, the thermodynamic products. The allenic or propargylic stannane reacted with stronger Lewis acidic halides such as a boron halide, antimony trichloride, or tin tetrachloride to give only the allenic product, even when the reaction was performed and analyzed at low temperature (−80 °C). The propargylic intermediate was observed with the antimony and tin compounds when a substituted derivative (e. g. Vi2SbCl, ViSnCl3) was used. The reduction of the propargylic halide products prior to their isomerization gave the corresponding primary propargylic phosphine, arsine, germane, and stannane.

Block copolymerization of allene derivatives with 1,3‐butadiene by living coordination polymerization with π‐allylnickel catalyst

Block copolymerization of allene derivatives with 1,3‐butadiene by living coordination polymerization with π‐allylnickel catalyst

Block copolymerization of allene derivatives with 1,3-butadiene by living coordination polymerization with ?-allylnickel catalyst

The block copolymerization of allene derivatives (3A–3D) with 1,3-butadiene (2) by [(allyl)NiOCOCF3]2 (1) is described. For instance, the living coordination polymerization of phenylallene (3A, 50 equiv) starting from the living poly(2), which was prepared by the polymerization of 2 (160 equiv) by 1, successfully gave a block copolymer of 2 and 3A in high yield. The molecular weight of the block copolymer (4A) in gel permeation chromatography shifted clearly to the higher molecular weight region and kept a unimodal distribution (Mn = 17,400, Mw/Mn = 1.23) in comparison with that of the starting living poly(2) (Mn = 5,600, Mw/Mn = 1.67). The ratio of each segment and the molecular weight of the resulting copolymers could be controlled by the feed ratio of each monomer. The block copolymerization also proceeded successfully by the inverse order of the monomer feeding (i.e., the polymerization of 3A followed by that of 2) to obtain the corresponding block copolymers in high yields. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3916–3921, 1999

1H and 13C NMR of Synthethic Allenic Derivatives from Eudesmanolides and Pseudoguayanolides

The allenic derivatives of biologically active natural sesquiterpenes were synthesized by two reaction sequence: addition of Seyferth reagent producing dibromocyclopropanes then the allenic derivative formation by Hiyama reaction. the structure of all products was determined using 1H and 13C NMR.

ChemInform Abstract: Development and Application of Living Coordination Polymerization of Allene Derivatives by Allylnickel Catalysts

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of novel reactive polymers bearing naphthalene moieties in the side chain by the living coordination polymerization of allene derivatives

Reactive polymers possessing both unsaturated double bonds and naphthalene moieties have been designed and synthesized on the basis of the living coordination polymerization of allene derivatives. For the monomers, 1- and 2-allenyloxymethylnaphthalene were prepared from 1− and 2-methylnaphthalene, respectively, and subsequently they were subjected to the coordination polymerization by [(allyl)NiOCOCF 3] 2 with or without PPh 3 ligand. Polymers composed of 1,2− and 2,3-polymerization units were obtained in high yields whose molecular weights and the ratio of 1,2− to 2,3-polymerization could be controlled successfully by the feed ratio of monomer to initiator and the ligand added to the catalyst systems, respectively. From the differential scanning calorimetric analyses, the polymers produced from these monomers were found to possess higher glass-transition temperatures ( T g) relative to the polymers from benzyloxyallene (i.e., a polymer bearing benzene rings instead of naphthalene moieties). The melting point ( T m) was observed in the case of the polymer prepared in the absence of ligands, while that prepared in the presence of PPh 3 did not reveal T m, indicating that the crystallinity of the polymer is dependent on the ligands used for the polymerization catalysts.

アリルニッケル触媒によるアレン類のリビング配位重合の開拓と応用

This article describes our recent works on the living coordination polymerization of allene derivatives by allylnickel catalysts. The polymerization of alkoxyallenes by allylnickel catalysts proceeds via a living process to give polymers with predictable molecular weights and narrow molecular weight distributions in excellent yields. The polymerization was carried out with allylnickel complexes bearing various ligands to figure out the clear effect on the polymer structures and the polymerization behavior. Similarly, allene derivatives bearing various substituents such as phenylallene, alkylallenes, allenylsulfide, allenylpyrrolidone, allenyloxazolidone, esters of allenic acid, and macromonomers bearing allenyloxy end groups undertake the living polymerization. Macromolecular designs based on the living polymerization of allene derivatives (e.g., block copolymerizations) are also described.

Inactivation of 4-oxalocrotonate tautomerase by 2-oxo-3-pentynoate.

The compound, 2-oxo-3-pentynoate, has been synthesized and tested as an inhibitor of the enzyme 4-oxalocrotonate tautomerase. The enzyme is rapidly and irreversibly inactivated by the acetylenic product analogue in a time-dependent fashion. The enzyme displays saturation kinetics and is protected from inactivation by the presence of substrate. These observations are consistent with inactivation taking place at the active site. Partial reactivation ( approximately 18%) occurs by incubating the inactivated enzyme with 10 mM hydroxylamine (pH 7.3). The partition ratio, determined to be approximately 0.4, suggests that the inactivation of 4-OT by 2-oxo-3-pentynoate shows half-of-the-sites stoichiometry. The same phenomenon is observed in the inactivation of 4-OT by 3-bromopyruvate and can be explained by examination of the crystal structure. Mass spectral analysis shows that a single residue is modified on the enzyme which has been localized to the nine residue amino-terminal fragment Pro-1 to Glu-9. It can be reasonably concluded that Pro-1 is the site of covalent attachment. Inactivation of 4-OT can occur by either a Michael addition of 4-OT to C-4 of 2-oxo-3-pentynoate or by the enzyme-catalyzed rearrangement of 2-oxo-3-pentynoate to an allene derivative which alkylates Pro-1. These results provide the foundation for the use of 2-oxo-3-pentynoate in future mechanistic studies and as a ligand in an inactivated 4-OT complex that can be studied by X-ray crystallography. Finally, 2-oxo-3-pentynoate is an acetylene analogue of a variety of 2-oxo acids and as such may have general utility as an inhibitor of reactions that bind and process these compounds.

Synthesis and Structure of Allenyl‐Substituted η6‐Benzene(tricarbonyl)‐chromium Complexes

AbstractThe Cr(CO)3‐complexed η6‐phenylpropargylic alcohols 3 react in a displacement rearrangement with thionyl chloride or chlorodiphenylphosphane to give the chloro‐ or phosphoryl allenyl substituted η6‐phenyl complexes 4 and 6, respectively. In the X‐ray crystal structure of the novel organometallic allenic derivatives 4b and 6b the vicinal chloro or phosphoryl substituent and the benzene(tricarbonyl)chromium fragment are arranged coplanarily. Palladium/copper‐catalyzed couplings of the chloroallene 4b with terminal alkynes disclose a facile access to ynallene derivatives 8, novel carbon‐rich organometallic π‐systems.

Coupling polymerization of monofunctional allene derivatives with malonates bearing aryl halides moieties via ?-allylpalladium complex

A novel polymerization method of allene derivatives with nucleophiles bearing aryl halide moieties (A-B type) is described. By the polymerization of hexylallene with malonates bearing an aryl iodide part, polymers consisting both of internal and exomethylene (exo) double bonds were obtained by mean of the coupling reaction of three different components in high yields. On the other hand, a polymer obtained from phenylallene was selectively composed of internal double bonds (E and Z). By the reaction of hexylallene with a malonate bearing two aryl halide moieties (A-B2 type), a multibranched polymer was also obtained. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2097–2103, 1997

Block copolymerization of allene derivatives with isocyanides by the coordination polymerization with π‐allylnickel catalyst

A living block copolymerization of allene derivatives with 1-phenylethyl isocyanide (3) using [(allyl)NiOCOCF3]2 (1) is described. After complete polymerization of allene monomers such as n-octyloxyallene (2A) with 1, further addition of 3 to the reaction system yielded the corresponding block copolymers in high yield. For instance, a block copolymer (4A, Mn = 39,600, Mw/Mn = 1.20) was obtained in 96% yield by the addition of 3 ([3]/[1] = 250) to the living solution of poly(n-octyloxyallene) (Mn = 14,400, Mw/Mn = 1.03) prepared by the polymerization of 2A in the ratio of [2A]/[1] = 90. The resulting copolymer was a brownish orange gum or a solid, depending on the length of each of the segments. The solubility of the block copolymers could be controlled by the allene components. The copolymer of 2A with 3 having appropriate length of segments was soluble in n-hexane, while that of methoxyethoxyethoxyallene (2D) with 3 was soluble in methanol. © 1997 John Wiley & Sons, Inc.

Block copolymerization of allene derivatives with isocyanides by the coordination polymerization with ?-allylnickel catalyst

A living block copolymerization of allene derivatives with 1-phenylethyl isocyanide (3) using [(allyl)NiOCOCF 3 ] 2 (1) is described. After complete polymerization of allene monomers such as n-octyloxyallene (2A) with 1, further addition of 3 to the reaction system yielded the corresponding block copolymers in high yield. For instance, a block copolymer (4A, M n = 39,600, M w /M n = 1.20) was obtained in 96% yield by the addition of 3 ([3]/[1] = 250) to the living solution of poly(n-octyloxyallene) (M n = 14,400, M w /M n = 1.03) prepared by the polymerization of 2A in the ratio of [2A]/[1] = 90. The resulting copolymer was a brownish orange gum or a solid, depending on the length of each of the segments. The solubility of the block copolymers could be controlled by the allene components. The copolymer of 2A with 3 having appropriate length of segments was soluble in n-hexane, while that of methoxyethoxyethoxyallene (2D) with 3 was soluble in methanol.

Axial chiral allenylacetates as novel ferroelectric liquid crystals

R. Lunkwitz, C. Tschierske, A. Langhoff, F. Gießelmann and P. Zugenmaier, J. Mater. Chem., 1997, 7, 1713 DOI: 10.1039/A701032J

ChemInform Abstract: Synthesis of Novel Liquid‐Crystalline Allene Derivatives with Ferroelectric Properties.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of Novel Liquid‐Crystalline Allene Derivatives with Ferroelectric Properties

AbstractSome new heterocyclic liquid‐crystalline compounds incorporating a 1,3‐disubstituted allene unit were synthesised. These axial‐chiral compounds were investigated by polarisation microscopy and differential scanning calorimetry. One of them was also synthesised in enantiomerically enriched form by enantioselective synthesis. It was found that the latter product exhibits a ferroelectric switchable chiral smectic C phase with an unexpectedly large value of the spontaneous polarisation.

Electrosynthesis of sulfur-containing organic compounds from allene derivatives using a sacrificial mixed sulfur/graphite electrode

Electrosynthesis of sulfur-containing organic compounds from aliene derivatives was studied using a sacrificial mixture sulfur/graphite electrode. 1,3-bis(methoxycarbonyl)propadiene ( 1a), 1,1,-diphenyl-3-ethoxycarbonyl-1, 2-butadiene ( 1b), 1,3-diphenylpropadiene ( 1c), and 1-(p-methoxyphenyl)-1,2-butadiene ( 1d) were used as allenes. With la, 6-membered ring compounds with 2S atoms such as dihydrodithiin ( 2a) and dithiin ( 3a) and a dimer bridged with 2S atoms ( 4a) were obtained and their yields were largely dependent on the kind of proton donors used. On the other hand, 1b afforded a 5-membered ring compound with 3S atoms such as 1,2,3-tirthiolane ( 5b) different from the case of 1a. All products will be initiated by the addition of the polysulfide anion produced by electroeduction of elemental sulfur. With 1c and 1d, sulfur-containing organic compounds were not produced.

AM1 study of photoelectron spectra.

A correlation was found between the group dipole moments of substituents determined from the dipole moments of ethylene derivatives and the second ionization potentials of allene derivatives corresponding to the π′-MO of the C(β)-C(γ) bond. It was shown that the concept of the effect of the substituent field cannot completely explain the observed phenomena, and the energies of the second ionic states of bromoallene and alkoxyallenes are lowered because of the interaction between nonbonded fragments through the σ systems of the compounds. It has been found that, in terms of orbital approximation, this interaction causes electronic destabilization of theanti-planar (trans) conformers of methoxyallene and methyl vinyl ether compared to theirsin-planar (cis) forms.

Metallation and functionalization of 1‐allenylpyrrole

Abstract1‐Allenylpyrrole is lithiated at the α‐carbon atom of the allenyl group by n‐butyllithium in mixtures of diethyl‐ether/hexane or tetrahydrofuran/hexane. Whereas functionalization with trimethylchlorosilane, butyl iodide and dimethyl disulfide gives only allenic derivatives, addition of carbonyl compounds generally leads to mixtures of allenic and acetylenic derivatives. Upon heating its solutions in ether or tetrahydrofuran, Li‐allenylpyrrole is slowly transformed into the lithium derivative of 1‐(propyn‐2‐yl)pyrrole.