Nucleophilicity and Electrophilicity Parameters for Predicting Absolute Rate Constants of Highly Asynchronous 1,3-Dipolar Cycloadditions of Aryldiazomethanes.

Kinetics of the reactions of aryldiazomethanes (ArCHN) with benzhydrylium ions (ArCH) have been measured photometrically in dichloromethane. The resulting second-order rate constants correlate linearly with the electrophilicities E of the benzhydrylium ions which allowed us to use the correlation lg k = s( N + E) (eq 1) for determining the nucleophile-specific parameters N and s of the diazo compounds. UV-vis spectroscopy was analogously employed to measure the rates of the 1,3-dipolar cycloadditions of these aryldiazomethanes with acceptor-substituted ethylenes of known electrophilicities E.

Electrophilicities of trans-β-nitrostyrenes.

The kinetics of the reactions of the trans-β-nitrostyrenes 1a-f with the acceptor-substituted carbanions 2a-h have been determined in dimethyl sulfoxide solution at 20 °C. The resulting second-order rate constants were employed to determine the electrophile-specific reactivity parameters E of the trans-β-nitrostyrenes according to the correlation equation log k(2)(20 °C) = s(N)(N + E). The E parameters range from -12 to -15 on our empirical electrophilicity scale (www.

trans-2-(2-Nitro-1-phenyl-eth-yl)cyclo-hexa-none.

In the title compound, C(14)H(17)NO(3), the plane of the phenyl ring and the least-squares plane of the cyclo-hexyl moiety enclose an angle of 89.14 (6)°. The cyclohexyl ring adopts a chair conformation.

Preparation of novel unsymmetrical bisindoles under solvent-free conditions: synthesis, crystal structures, and mechanistic aspects.

Indole aziridines and their hydroxyl derivatives have been used for the preparation of a small library of novel functionalized bisindoles. Diversification of these building blocks by solvent-free C-C-bond formation on solid support yielded annulated Hymenialdisine analogues under mild reaction conditions. Indoles as C-nucleophiles form potentially pharmacologically active bisindoles through an electrophilic aromatic substitution pathway in good to excellent yields.