Silacyclohexanes and silaheterocyclohexanes: Synthesis, stereochemistry and conformational analysis

International Conference on Stereochemistry

August 18-19, 2016 Sao Paulo, Brazil

Bagrat Shainyan

AE Favorsky Irkutsk Institute of Chemistry, Russia

Posters & Accepted Abstracts: Med chem

Abstract :

The studies of cyclohexanes were a keystone of modern conformational analysis. In contrast, until recently, silacyclohexanes and even more so silaheterocyclohexanes were much less studied. The principal question is if the introduction of silicon leads to consequences different from those caused by other heteroatoms. The answer is �yes�, and the lecture will focus on the reasons. Principal differences of sila(hetero)cyclohexanes from cyclohexanes are different conformational preferences (low or even negative conformational energy of substituents at silicon), much lower inversion barriers in sila(hetero)cyclohexanes, different importance of steric and electronic effects (predominance of steric effects in cyclohexanes and of electrostatic effects in sila(hetero)cyclohexanes), additivity of conformational effects in silacyclohexanes vs. their nonadditivity in cyclohexanes, the absence of principal difference between gas and solution for cyclohexanes in contrast to the often observed reverse of conformational preferences in gas and solution for silaheterocyclohexanes. The effect of the second heteroatom in silaheterocyclohexanes will also be discussed. The conclusion that will be made is that silacyclohexanes and the more so silaheterocyclohexanes are very interesting compounds, which are principally different from their carbon analogs. The difference concerns not only structural and conformational properties, but also their synthetic behavior and patterns of reactivity, as will be demonstrated in the lecture.

Biography :

Email: bagrat@irioch.irk.ru