The specific rates of solvolysis of isobutyl fluoroformate (1) have been measured at 40.0 °C in 22 pure and binary solvents. These results correlated well with the extended Grunwald-Winstein (G-W) equation, which incorporated the N(T) solvent nucleophilicity scale and the Y(Cl) solvent ionizing power scale. The sensitivities (l and m-values) to changes in solvent nucleophilicity and solvent ion...

Specific rates of solvolysis at 25 degrees C for isopropyl chloroformate (1) in 24 solvents of widely varying nucleophilicity and ionizing power, plus literature values for studies in water and formic acid, are reported. Previously published solvolytic rate constants at 40.0 degrees C are supplemented with two additional values in the highly ionizing fluoroalcohols. These rates are now are anal...

The mechanism of the intramolecular Diels–Alder (IMDA) reaction of benzoquinone 1, in the absence and in the presence of three water molecules, 1w, has been studied by means of density functional theory (DFT) methods, using the M05-2X and B3LYP functionals for exploration of the potential energy surface (PES). The energy and geometrical results obtained are complemented with a population ...

Second order rate constants for reactions of 4,4'-dimethylaminobenzhydrylium cations with amines and other nucleophiles in water define a scale of nucleophilicity (N(+)'' = log k + 2.63). The N(+)'' scale can be extended by linking directly to an established N(+) scale based on reactions of methyl vinyl pyridinium cations with amine nucleophiles. Logarithms of rate constants for other benzhydry...

Difluoroenol silyl ethers are a unique class of enol that widely used as powerful difluoroalkylating reagent to incorporate difluoromethylene groups into organic molecules. In this context, we revealed fluorine effect the difluoroenol exhibit oxygen nucleophilicity in lieu traditional α-carbon toward aromatic iodonium/sulfonium species, thus allowing us develop difluoroalkylative [3,3]-rearrang...

The cyano(triphenylsilyl)phosphanide anion was prepared as a sodium salt from 2-phosphaethynolate. electronic structure of this new cyano(silyl)phosphanide studied via computational methods and its reactivity investigated using various electrophiles Lewis acids, demonstrating P- N-nucleophilicity. ambident is in agreement with computations. silyl group also shows lability therefore the can be c...

A new activator for the coupling of phosphoramidites to the 5'-hydroxyl group during oligonucleotide synthesis is introduced. The observed time to complete coupling is twice as fast with 4, 5-dicyanoimidazole (DCI) as the activator, compared with 1 H -tetrazole. The effectiveness of DCI is thought to be based on its nucleophilicity. DCI is soluble in acetonitrile up to 1.1 M at room temperature...

Dedicated to Professor Heinrich Nöth on the occasion of his 85th birthday The nucleophile-specific parameters N and sN, as defined by the linear free energy relationship log k = sN(N +E) (J. Am. Chem. Soc. 2001, 123, 9500 – 9512), were determined for five imines 1a–e by studying the kinetics of their reactions with benzhydrylium ions in dichloromethane solution at 20 ◦C. These parameters allowe...