Correlation between biological activity and energies of electronic transitions in benzodiazepines. Negative ion mass spectrometry and ultraviolet absorption spectroscopy study of some derivatives

A correlation between the energies of electronic singlet transitions in benzodiazepines and their biological activity, which was revealed earlier by means of negative ion mass spectrometry with resonance electron capture, has been verified with a UV absorption spectroscopy investigation. Also, it has been noted that the energies of electronic singlet transitions in benzodiazepines are close in value to the ionization energies of atoms Cs, Rb, K, Na, Li and Tl, the cations of which are known to play an important role in nerve cell excitation processes. Copyright 1999 John Wiley & Sons, Ltd.     

Iridium-catalyzed asymmetric hydrogenation of imines in supercritical carbon dioxide using phosphite-type ligands

A series of chiral phosphite-type ligands has been evaluated in the iridium-catalyzed asymmetric hydrogenation of acyclic arylimines in supercritical CO₂. High reactivities (100% conversion in 50-120 min) and enantioselectivities (up to 95%) were obtained.     

Solid-state synthesis of chiral ferrocenylaldimines from methyl esters of α-amino acid hydrochlorides in the presence of potassium carbonate

The solid-state interaction of the three-component mixtures (ferrocenylcarbaldehyde: methyl ester of amino acid hydrochloride: K₂CO₃) afforded new optically active Schiff bases. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 583–586, March, 1999.     

Gas-phase deprotonation of arylalkylamines. A collision-induced dissociation study

The collision-induced dissociation (CID) of deprotonated arylalkylamines of general formula R(1)C(6)H(4)CHR(2)CH(2)NR(3)(2) (where R(1) = H, OH, F or NO(2); R(2) = H or OH; R(3) = H or CH(3)) generated by negative chemical ionization with H(2)O and D(2)O as ionizing reagents, is discussed. The negative chemical ionization mass spectra show that, in the absence of a hydroxy group in the aromatic ring, deprotonation takes place at the benzylic position whereas the proton is lost from the OH group when present. The nitro compound forms only M(-.) ions. The CID spectra of the deprotonated molecules show that fragmentations are strongly dependent on the structural features of the molecules, namely the presence or absence of substituents in the aromatic ring or aliphatic chain. Copyright 1999 John Wiley & Sons, Ltd.     

Model solid-state reactions for the formation of a peripheral layer of organometallic dendrimers. Solid-state α-ferrocenylethylation of phenols

With the aim of modifying solid dendrite structures, the solid-state reactions of (S)-(−)-(1-trimethylammonio)ethylferrocene iodide with substituted phenols were studied. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1112–1114, June, 2000.