title: Theoretical examination of the S-C-P anomeric effect.
abstract: Three decades after the discovery of a strong S-C-P anomeric effect in 2-diphenylphosphinoyl-1,3-dithiane (1) and 2-trimethylphosphonium-1,3-dithiane (4), its definitive interpretation is still lacking. The present study reports DFT geometry optimizations of 1-ax, 1-eq, 4-ax, and 4-eq, which do reproduce the S-C-P anomeric effect in 1 and 4, worth 5.45 and 3.08 kcal/mol, respectively (in chloroform solvent). Weinhold's NBO analysis supports the existence of dominant nX → σ*C-Y stereoelectronic interactions that stabilize the axial conformers.
authors: Departamento de Química, Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional , Apartado Postal 14-740, 07000 Mexico, D. F., México.
authors: Eusebio
authors: E
authors: Juaristi
authors: Rafael
authors: R
authors: Notario