title: Dimerization reactions of aryl selenophen-2-yl-substituted thiocarbonylS-methanides as diradical processes: a computational study.
abstract: An intriguing stepwise diradical mechanism of the dimerization of the reactive intermediate (thiocarbonylS-methanide) appearing in the reaction of phenyl selenophen-2-yl thioketone with diazomethane was studied by means of computational methods. The preferred formation of the unusual macroheterocycle, competitive with the 1,3-ring closure leading to a thiirane and the head-to-head dimerization yielding a 1,4-dithiane derivative, respectively, was explained based on the analysis of the structure of the favored conformer of the intermediate, delocalized diradical species. The influence of selenium as a 'heavy atom' for stabilization of this intermediate has been emphasized.
authors.affiliation: Auburn University, Department of Chemistry and Biochemistry, Auburn, AL, 36849, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: McKee
authors.affiliation: Department of Organic and Applied Chemistry, University of Łódź, Tamka 12, PL 91-403 Łódź, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Mlostoń
authors.affiliation: Department of Organic and Applied Chemistry, University of Łódź, Tamka 12, PL 91-403 Łódź, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Urbaniak
authors.affiliation: Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
authors.forename: Heinz
authors.initials: H
authors.lastname: Heimgartner
keywords: 1,3-dipolar cycloadditions; reaction mechanisms; reactive intermediates; thiocarbonyl S-methanides; thioketones