title: Orbital phase environments and stereoselectivities.
abstract: Facial selections are reviewed to propose a new theory, orbital phase environment, for stereoselectivities of organic reactions. The orbital phase environment is a generalized idea of the secondary orbital interaction between the non-reacting centers and the unsymmetrization of the orbitals at the reacting centers arising from in-phase and out-of-phase overlapping with those at the neighboring non-reacting sites. In this context, the nucleophilic addition preferentially occurs on the face of the carbonyl functionality opposite to the better electron-donating orbital at the β position. In a similar manner to the carbonyl cases, the preferred reaction faces of olefins in electrophilic addition reactions are opposite to the better electron-donating orbitals at the β positions. The orbital phase environments in Diels-Alder reactions are also reviewed.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113, Japan, ohwada@mol.f.u-tokyo.ac.jp.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Ohwada
mesh_terms: D061565:Cycloaddition Reaction; D004583:Electrons