Kinetic Studies that Evaluate the Solvolytic Mechanisms of Allyl and Vinyl Chloroformate Esters
نویسندگان
چکیده
At 25.0 °C the specific rates of solvolysis for allyl and vinyl chloroformates have been determined in a wide mix of pure and aqueous organic mixtures. In all the solvents studied, vinyl chloroformate was found to react significantly faster than allyl chloroformate. Multiple correlation analyses of these rates are completed using the extended (two-term) Grunwald-Winstein equation with incorporation of literature values for solvent nucleophilicity (NT) and solvent ionizing power (YCl). Both substrates were found to solvolyze by similar dual bimolecular carbonyl-addition and unimolecular ionization channels, each heavily dependent upon the solvents nucleophilicity and ionizing ability.
منابع مشابه
Influence of Sulfur for Oxygen Substitution in the Solvolytic Reactions of Chloroformate Esters and Related Compounds
The replacement of oxygen within a chloroformate ester (ROCOCl) by sulfur can lead to a chlorothioformate (RSCOCl), a chlorothionoformate (ROCSCl), or a chlorodithioformate (RSCSCl). Phenyl chloroformate (PhOCOCl) reacts over the full range of solvents usually included in Grunwald-Winstein equation studies of solvolysis by an addition-elimination (A-E) pathway. At the other extreme, phenyl chlo...
متن کاملDisubstituted Carbenium Ions as Reactive Intermediates in Organic Chemistry
Recent results in the chemistry of disubstituted carbenium ions (vinyl cations and phenyl cations) are described separately under three different sections: From kinetic and solvolytic data of several 1—cyclobutenyl nonaflates, the intermediacy of a non-classical vinyl cation, namely the 1-cyclobutenyl cation 2 is established. Cycloaddition reactions of solvolytically generated vinyl cations wit...
متن کاملKINETIC STUDIES USING SEMI-EMPIRICAL SELF- CONSISTENT FIELD (SCF) MOLECULAR ORBITAL (MO) METHOD: PARTI. A MODIFIED NEGLECT OF DIATOMIC OVERLAP (MNDO) STUDY OF THE PYROLYSIS OF ETHYL VINYL ETHER
Using a computer code called MOPAC, an acronym for a general Molecular Orbital Package (Quantum Chemistry Programme Exchange (QCPE) Programme No. 455), the geometries and heats of formation of the reactant, the products and the trdnsition state were computed by the MNDO semi- empiricalself consistent field (SCF) method for the pyrolysis of ethyl vinyl ether. ((Force))calculation on the reac...
متن کاملKINETIC STUDIES USING SEMI-EMPIRICAL SELF- CONSISTENT FIELD (SCF) MOLECULAR ORBITAL (MO) METHOD: PART I1 [I] A MODIFIED NEGLECT OFDIATOMIC OVERLAP (MNDO) STUDY OF THE PYROLYSES OF CHLOROETHYL VINYL ETHERS
The effect of monochloro and dichloro substitution into the ethyl portion on the pyrolysis of ethyl vinyl ether has been studied. This involved four possible monosubstituted derivatives and six disubstituted derivatives. For the monochloro derivatives, B- chloro substitution enhanced the rate constant while a- chloro substitution depressed it noticeably. For the dichloro derivatives, substi...
متن کاملRegio- and stereoselective anomeric esterification of glucopyranose 1,2-diols and a facile preparation of 2-O-acetylated glucopyranosyl trichloroacetimidates from the corresponding 1,2-diols.
A highly regio- and stereoselective anomeric esterification of 3-O-allyl (or benzyl, or benzoyl)-4,6-O-isopropylidene-alpha,beta-d-glucopyranose with acetyl chloride, or allyl chloroformate, or ethyl chloroformate gave the corresponding 2-OH, 1-beta-acetates or -carbonates in excellent yields. The 2-OH, 1-beta-acetates were readily converted to the corresponding 2-O-acetylated glucopyranosyl tr...
متن کامل