People's Deputy: Yuri D. Chernichenko

This repository item contains a single article of the Publication Series, papers in areas of particular scholarly interest published from 1989 to 1996 by the Boston University Institute for the Study of Conflict, Ideology, and Policy. The volume this article belongs to is titled "Soviet People's Deputies speak"

A frustrated-Lewis-pair approach to catalytic reduction of alkynes to cis-alkenes

Frustrated Lewis pairs are compounds containing both Lewis acidic and Lewis basic moieties, where the formation of an adduct is prevented by steric hindrance. They are therefore highly reactive, and have been shown to be capable of heterolysis of molecular hydrogen, a property that has led to their use in hydrogenation reactions of polarized multiple bonds. Here, we describe a general approach to the hydrogenation of alkynes to cis-alkenes under mild conditions using the unique ansa-aminohydroborane as a catalyst. Our approach combines several reactions as the elementary steps of the catalytic cycle: hydroboration (substrate binding), heterolytic hydrogen splitting (typical frustrated-Lewis-pair reactivity) and facile intramolecular protodeborylation (product release). The mechanism is verified by experimental and computational studies

Metal-free hydrogenations catalyzed by frustrated ansa-aminoboranes

Frustrated Lewis pairs (FLPs) are powerful, typically nonmetal, Lewis acid/base combinations that can split dihydrogen (H2) heterolytically, due to their inability to form conventional Lewis adducts (usually as a result of steric repulsion). The H2 thus activated can be transferred to various substrates in a catalytic fashion. The scope of substrates catalytically hydrogenated with FLPs is rapidly expanding, approaching that of transition-metal-catalyzed hydrogenations. The discovery of FLPs is, perhaps, one of the most remarkable recent findings in the field of main group organometallic compounds. The literature review part provides a brief critical overview of heterolytic H2 splitting with FLPs, including the thermodynamic, mechanistic, and catalytic aspects of this process. Particular emphasis is placed on the Lewis acidity of various boranes, since this factor is critical for the ability of FLPs to split H2 and provides a basis for introducing fluoroaryl-free boranes into the FLP area. The experimental section of the thesis is devoted to the development of FLP catalysts, based on an ansa-aminoborane core for hydrogenation of various substrates. Within the study, various parts of the ansa-aminoborane molecule were modified: a amine group, resulting in highly active ansa-aminoboranes for hydrogenation of imines and other nitrogen-containing compounds, also featuring other unique properties; a mutual B/N geometry (changing the nature of the link), resulting in an ansa-catalyst for hydrogenation of unactivated alkynes; and a borane part, revealing that lightweight and inexpensive ansa-aminochloroboranes show reactivity to H2 similar to that of C6F5 boranes, including catalytic abilities. A book chapter covering recent progress in frustrated borane/amine Lewis interaction, involving ansa-systems was included in the thesis.Molekyylien pelkistäminen vetykaasulla on orgaanisen kemian tärkeimpiä reaktioita. Useimmiten reaktio ei etene itsestään, vaan siihen tarvitaan katalyytti. Vedytyskatalyytit sisältävät tavallisesti kalliita jalometalleja kuten palladiumia, platinaa, rodiumia tai ruteniumia. Vety siirtyy substraatille labiilin metalli-H2 välituotteen kautta. Hiljattain on osoitettu, että tietynlaiset metallittomat yhdisteet, joita kutsutaan turhautuneiksi Lewis-pareiksi, voivat reagoida vedyn kanssa ja jopa toimia katalyytteina monissa pelkistysreaktiossa. Tässä työssä käsitellään yhdisteitä, joiden aktiiviset keskukset, boori ja typpi, on tuotu samassa molekyylissä toistensa lähelle (ansa-aminoboraanit). Nämä ovat tehokkaita vedytyskatalyytteja monille erilaisille substraateille. Työssä syntetisoitiin myös moolimassaltaan kevyitä aminoboraaneja, jotka osoittavat mahdollisuuden käyttää tällaisia yhdisteitä vedyn varastointia varten

Reconstructing a non-local separable interaction in the framework of the relativistic quasipotential model

In the framework of the relativistic quasipotential approach to the quantum field theory, a method is developed according to which a non-local separable quasipotential describing the interaction between two relativistic spinless parti­cles of unequal masses can be reconstructed by of the phase shift and bound-state energies

Form Factor of the Relativistic Two-particle System in the Relativistic Quasipotential Approach: The Case of Arbitrary Masses and Vector Current

A new relativistic form factor for a bound two-particle system was obtained for the case of a vector current. The present consideration was performed within the relativistic quasipotential approach based on the covariant Hamiltonian formulation of quantum field theory by going over to the three dimensional relativistic configuration representation for the case of interaction between two relativistic spinless particles of arbitrary mass

Relativistic Inverse Problem for the Superposition of a Non-Local Separable Interaction and a Local Quasipotential not Admiting Bound State

Within the relativistic quasipotential approach to quantum field theory, a relativistic inverse problem is considered for the superpo­sition of a non-local separable quasipotential and a local one that simulates the interaction between two relativistic spinless particles of unequal masses. Besides, the local part of total interaction is supposed to be known and that it does not admit bound states. Then a non-local separable part of total interaction can be recon­structed on the basis of the additional phase-shift and bound-state energies