Presence Of Butyllithium Research Articles

ChemInform Abstract: Some Fluorinated Heterocyclic and Acyclic Derivatives of Chlorocarbonylsulfenyl Chloride.

AbstractReaction of the fluorinated alcohols (II) with chlorocarbonylsulfenyl chloride (I) in the presence of pyridine or triethylamine as the base results in a mixture of the sulfenates (III) and the carboxylates (IV), while in the presence of butyllithium only the compounds (III) are obtained.

ChemInform Abstract: An Efficient Method for Polyphosphorylation of Inositol Derivatives.

AbstractTreatment of the inositols (I) with tetrabenzyl pyrophosphate (II) in the presence of butyllithium and/or LDA yields the phosphorylated derivatives (III).

ChemInform Abstract: Migration of Silicon from Oxygen to Carbon in O‐Trialkylsilyl Ketene Acetals.

AbstractThe O‐silyl‐O'‐cyclohexyl ketene acetals (III) are prepared from the cyclohexyl acetates (I) and the chlorosilanes (II) in the presence of butyllithium.

ChemInform Abstract: Phosphine‐Substituted Chelate Ligands. Part 22. α‐Phosphorus‐Substituted N‐Methyl Carboxylic Acid (Thio)Amides.

AbstractThe α‐diphenylphosphanocarboxylic thioamide (IIIc) is prepared from diphenylbenzylphosphane (Ic) and methyl isothiocyanate (II) in the presence of butyllithium.

ChemInform Abstract: A Simple Synthesis of γ‐Hydroxy‐α,β‐Unsaturated Aldehydes.

AbstractThe cyclohexenones (I) are coupled with the dithiane (II) in the presence of butyllithium, yielding the α‐hydroxy dithioacetals (III) which are cleaved to form the 3‐hydroxycyclohexene‐1‐carbaldehydes (IV).

ChemInform Abstract: Asymmetric Synthesis of the Both Enantiomers of Tertiary Aryl Homoallyl Alcohols and Diols by Diastereoselective Addition of Allyltrimethylsilane to Chiral α‐Keto Imides.

AbstractThe chiral α‐keto imides (III) are prepared from the optically active oxazolidinones (II) and the α‐keto acyl chlorides (I) in the presence of butyllithium.

A New Synthesis of Polysubstituted Cyclopropanes

Abstract Polysubstituted cyclopropane derivatives (3a-3h) could be obtained by reaction of activate olefinic compounds (2) with the cyanophosphates (1) aldehydes (benzaldehyde, cinnamaldehyde and croton-aldehyde) in the presence of butyllithium and tetra-methylethylenediamine in tetrahydrofuran via a Michael addition followed by 1,3-elimination.

ChemInform Abstract: A Simple, Powerful, and Efficient Method for Transesterification.

AbstractIn Gegenwart von Butyllithium lassen sich Methylester (I) mit einer Reihe verschiedener Alkohole (II) zu den Verbindungen (III) umestern.

A simple, powerful, and efficient method for transesterification

Aromatic and α,β-unsaturated methyl esters undergo efficient transesterification at ambient temperature or below with primary, secondary, or (particularly) tertiary alcohols in the presence of butyl-lithium in tetrahydrofuran solution.

ChemInform Abstract: Anion Radical‐Induced Desilylation of Organosilane. Reactions of Benzylsilanes with Aldehydes and Related Compounds in the Presence of Butyllithium or Lithium Metal.

AbstractBei der Einwirkung von BuLi auf Benzylsilane (I) in Gegenwart von Aldehyden (II) entstehen unter Desilylierung die Diol‐Derivate (III).

Microstructure of poly(methyl sorbate)

Anionic polymerization of methyl sorbate produces polymers of different microstructures according to the catalytic system employed. An examination of the i.r., 1H- and 13C-NMR spectra, for poly(methyl sorbate) and for the saturated polymer obtained by non-catalytic reduction of the double bond, together with comparison with low-molecular-weight model compounds, makes it possible to assign an erythro-structure to the polymer obtained in the presence of butyl lithium and a threo-structure to the polymer obtained in the presence of the catalytic system(butyl lithium + tetramethylurea). The steric purity of such polymers is rather low.

THE SYNTHESIS OF ETHYL 2-ETHOXYCARBONYL-3,5-DIOXOHEXANOATE

Abstract Ethyl 2-ethoxycarbonyl-3,5-dioxoiiexanoate (1-b) was synthesized by the hydrogenolysis and hydrolysis of diethyl (3-methyl-5-isoxazolyl)malonate (3-b), which was obtained by the di-carboxylation of 3,5-dimethylisoxazole (4) with ethyl cyanoformate in the presence of butyllithium.

Synthesis and polymerization of some optically active 2‐ and 1,2‐substituted butadienes

AbstractDehydration of (S)‐3,5‐dimethyl‐1‐hepten‐3‐ol gave: (3E)‐ (I) and (3Z)‐(5S)‐3,5‐dimethyl‐1,3‐heptadienes (II) and 2‐[(S)‐ 2‐methylbutyl]‐1,3‐butadiene (III). 2‐[(S)‐1‐Methylpropyl]‐1,3‐butadiene (IV) was also prepared similarly by dehydration of (S)‐3,4‐dimethyl‐1‐hexene‐3‐ol. Monomers I–IV we polymerized in the presence of the TiCl4–Al(i‐C4H9)3 catalyst system and in emulsion with K2S2O8 as initiator. Monomer IV was also polymerized in the presence of butyllithium. Specific rotations of polymers are of the same order of magnitude as that of monomers, with exception of polymers prepared by stereospecific polymerization of (S)‐I and (S)‐II. The acetone‐soluble fraction of these polymers has a molar rotation similar to that of monomer, while the acetone‐insoluble part has a lower rotation ([M]D of monomer +53.2°; [M]D of polymer, +5.9°).

Copolymerization of vinyltrimethylsilane with styrene in the presence of butyllithium

1. The anionic copolymerization of vinyltrimethylsilane with styrene was conducted in the presence of butyllithium, and copolymers were obtained from the indicated monomers. 2. The relative activity of the pair styrene-vinyltrimethylsilane in the process of anionic copolymerization was investigated. The constant of the relative activity of styrene is 5.7±0.03, while that of vinyltrimethylsilane is 0.06±0.01.

Polymerization of Chloroprene in the Presence of Organometallic Compounds: The System Chloroprene-Butyllithium

Abstract In the polymerization of chloroprene in the presence of butyl lithium, a substantial role is ascribed to reactions of deactivation of growing chains, which prevents the possibility of attaining a high degree of conversion. Kinetic data indicate the anionic mechanism of the process.

Kinetics and mechanism of the polymerization of t-butyl methacrylate in presence of butyllithium

1. The kinetics of the polymerization of t-butyl methacrylate (t-BMA) in toluene in presence of butyllithium were investigated, and the apparent constants, activation energies, and preexponential factors of the elementary reactions were calculated. 2. The high values of the preexponential factors in the Arrhenius equation for the elementary reactions have given rise to the considerable values of the apparent constants of the elementary reactions. 3. The complex compounds formed as intermediate products in the elementary reactions are less stable than in the case of methyl methacrylate (MMA) and butyl methacrylate (n-BMA). 4. The higher ratio of the constant for the generation of active centers to the constant for chain propagation has determined the absence of an induction period in the polymerization and the formation of polymers of lower molecular weight than in the case of MMA and n-BMA. 5. In the polymerization of alkyl methacrylates,butyllithium is consumed to the extent of 0.5–6% in the generation of active centers, but most of it is consumed by reaction at the C=O bond.

Polymerization of chloroprene in the presence of organometallic compounds—I. The system chloroprene-butyllithium

Abstract In the polymerization of chloroprene in the presence of butyl lithium, a substantial role is ascribed to reactions of deactivation of growing chains, which prevents the possibility of attaining a high degree of conversion. Kinetic data indicate the anionic mechanism of the process.

Polymerization of vinylcarbazole in the presence of butyllithium and titanium tetrachloride

AbstractThe polymerization of large cyclic vinyl compounds is of considerable interest in the interpretation of the mechanism of action of complex organometallic catalysts. Numerous vinyl compounds have been investigated up to now but no study has been made of compounds containing large rings. Studies on the isotactic polymerization of vinylcarbazole have brought to light very important facts permitting of a number of inferences as to the mechanism of isotactic polymerization. Despite the large molecular volume of vinylcarbazole and the steric hindrances that should be expected due to this, a study of the polymerization kinetics has revealed reaction rates similar to those observed in the polymerization of other monomers. The study of the polymerization of vinylcarbazole and of other monomers showed that the butyllithium‐titanium chloride catalyst belongs to the class of organometallic complexes that act either by a stepwise or ionic mechanism. The specific features of complex organometallic catalysts in the polymerization of vinylcarbazole are evidently associated with preliminary activation of the active centers during which activation of the monomer also takes place. The formation of polymers with an isotactic microstructure is due to one of the possible mechanism of the catalysis, namely, to nonstepwise action. In the polymerization of vinylcarbazole in the presence of organolithium compounds and titanium tetrachloride the microstructure of the resultant polymer and the rate of polymerization depend upon the formation of other than primary complex compounds. The microstructure of isotactic polyvinylcarbazole shows a particular shape of spherulites, depending upon the nature of the catalyst.