Leonid B.Volodarsky Professor, Doctor of Science, Ph.D., The Founder of the Laboratory of Nitrogenous Compounds

TITLES, EDUCATION:

1994 Russian Federation State Prize Winner in Science
1989 Chairman of IUPAC International Conference on Nitroxide Radicals, Novosibirsk, USSR
1976 Full Professor of the chair Organic Chemistry, Novosibirsk State University
1972 Doctor of Chemical Science (Doctor Nauk), Institute of Organic Chemistry, Academy of Sciences, Novosibirsk
1963 Ph.D.in Chemistry, Institute of Organic Chemistry, NovosibirskEXPERIENCE, EMPLOYMENT:
1980-1998 Head of Laboratory of Nitrogenous Compounds, Institute of Organic Chemistry, Academy of Sciences, Novosibirsk
1970-1995 Lectures and seminars in general course "Organic Chemistry", Novosibirsk State University
1991 Aug. XIII International Congress of Heterocyclic Chemistry, OR, USA, Plenary lecture "Imidazoline Nitroxides. Synthesis and Applications"
1989 Sep. IUPAC International Conference on Nitroxide Radicals, Novosibirsk, USSR. Plenary lecture "Advances in the Chemistry of Stable Nitroxides"
1970-1976 Associate Professor of the chair Organic Chemistry, Novosibirsk State University
1962-1980 Senior Scientific Fellow of Laboratory of Organic Reaction Mechanisms, Institute of Organic Chemistry, Academy of Sciences, Novosibirsk

AREAS OF COMPETENCE:

• Organic Chemistry.
• Synthesis of Fine Bifunctional Derivatives of Hydroxylamine and Heterocyclic Compounds Based on Them.
• Chemistry of Stable Nitroxide Radicals as Spin Labels and Probes.
• Chemistry of Nitrones and Heterocyclic N-Oxides as Spin Traps and Substances Releasing Nitrogen Oxide.
• Synthesis of Biologically Active Compounds and Ligands.
• Chemistry of Polymer Additives: Inhibitors, Initiators, Antioxidants.

SCIENTIFIC SCHOOL, PUBLICATIONS:

18 Ph.D.Theses and 4 Doctor of Sciences Theses in the frame of this laboratory were carried out. The list of publications includes more than 340 papers, 10 reviews, more than 70 licenses and patents, 3 monographs in USA and 1 in Russia

Monographs:

1. "Synthetic Chemistry of Stable Nitroxides" L.B.Volodarsky, V.A.Reznikov, V.I.Ovcharenko, 226pp.,CRC Press,Inc.,Boca Raton, FL, USA, 1994.
2. "Imidazoline Nitroxides",(ed.L.B.Volodarsky), Vol.1, Synthesis and Properties, 222pp., Vol.2, Applications, 162pp., L.B.Volodarsky, I.A.Grigor'ev, V.A.Reznikov et al., CRC Press, Inc., Boca Raton, FL, USA, 1988.
3. "Stable Imidazoline Nitroxides" (eds. L.Berliner, J.Reuben), L.B.Volodarsky, I.A.Grigor'ev, R.Z.Sagdeev, 73pp., in Biological Magnetic Resonance, Vol.2, Plenum Press, New York, USA, 1980.
4. "Imidazoline Nitroxyl Radicals", L.B.Volodarsky et. al., (ed.Yu.N.Molin), 216pp., Nauka, Novosibirsk, USSR, 1988.

PRINCIPAL RESEARCH INTERESTS:

Organic hydroxylamine derivatives attract an attention of the researchers as metabolites of oxidation processes and initial compounds for the synthesis of nitrones, nitroxide radicals and heterocyclic N-oxides. Additional oxo-,hydroxyimino-, hydroxy- or other group in adjacent position provides the possibility of producing various heterocycles. 1,2-Hydroxylaminoketones and hydroxylaminooximes possess a number of properties related to presence of two reactive groups and were used to produce 4-, 5-, 6- and 8-membered heterocycles. Their capability to react with aldehydes and ketones affords cyclic hydroxylamines, oxidation of which easily gives stable nitroxide radicals (SNR). The SNR have found wide applications as spin labels, probes and traps in molecular biology and medicine, as ligands for materials with ferromagnetic properties, as inhibitors in polymer processing, as initiators for "living" radical polymerization etc. The main investigation directions of laboratory therefore:

• The development of methods to produce hydroxylaminoketones, hydroxylaminooximes, bishydroxylamines etc., including their most simple derivatives from accessible olefines and ketones.
• The use of these compounds to synthesize N-oxides of pyrazine imidazoline, 2H- and 4H-imidazole and diazetine, which invoke interest as traps for short lived radicals and substances releasing nitrogen oxide.
• The development of methods for manufacturing of the SNR of imidazoline, piperidine and tetrahydropyrimidine series involving various functional groups providing chelation both without or with the participation of radical center as well as their possible use as spin labels, inhibitors, initiators etc.
• The development of synthetic procedures based on isonitrosoketones and nitrosophenols to produce polynitrogen heterocyclic compounds in furoxane, furazane and triazole series and their benzoanalogues.

RESEARCH ACTIVITY (1993-1998):

To provide the expansion of a set of basic acyclic compounds derivatives a procedures for the synthesis of bishydroxylamines, hydroxylaminoamines and hydroxylaminoalcohols have been developed. On the basis of bishydroxylamines it was realized the synthesis of 1,2,3-triazole-2-oxides and 2-hydroxytriazoles representing unavailable derivatives with nitrogen-oxygen bond in position 2. With the same goal of the expansion the synthesis of new 1,2-hydroxylaminooximes containing pyridine or thiophene cycle conjugated with oxime group has been carried out. Basing on these compounds open and cyclic nitrones and nitroxide radicals were synthesized. Recently ammonium acetate catalytic effect on 1,2-hydroxylaminooximes, 1,2-hydroxylaminoketones and 1,2-hydroxylaminoalcohols condensation with ketones was observed which provided a large variety of new hindered derivatives of 1-hydroxy-3-imidazoline and 1-hydroxyoxazolidine. It was also shown that a stability of nitroxide radical can be provided not only by alkyl groups at alpha carbon atoms, but also by aryl-, and alkoxy-groups and even by hydrogen atom if hindered rotation maintains C-H bond in the nodal plane thus inhibiting the disproportionation.

In the last decade the use of alpha-diketone monooximes (isonitrosoketones or tautomeric O-nitrosophenols) turned to be promising for the synthesis of heterocyclic compounds. Thus, pyrrolidine N-oxide derivatives readily resulted in from an interaction of isonitrosoketones with enamines or with ketones and amines. These derivatives were demonstrated to be of interest as synthetic equivalents od 1,4-dicarbonyl compounds and therefore convenient synthons in the synthesis of pyrroles, indoles, pyridazines, cynnolines etc.

Last updated: February 17, 2000