title: Radical-mediated reduction of the dithiocarbamate group under tin-free conditions.
abstract: Reductive desulfurisation of dithiocarbamates is conveniently achieved using H(3)PO(2)-Et(3)N-ACCN in refluxing dioxane. Fused and spirocyclic β-lactams, prepared through 4-exo trig carbamoyl radical cyclisation-dithiocarbamate group transfer reactions, are reduced without fragmentation of the strained 4-membered ring. Diethyl tetraacetyl-d-glucopyranosyl dithiocarbamate is selectively reduced with or without acyloxy group migration depending on reaction conditions and choice of reductant. Deuterium incorporation from D(3)PO(2)-Et(3)N is observed for a system involving a nucleophilic radical intermediate, but not in the case of the electrophilic radical obtained through acyloxy group migration on a glucose derivative.
authors.affiliation: School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: McMaster
authors.forename: Robert N
authors.initials: RN
authors.lastname: Bream
authors.forename: Richard S
authors.initials: RS
authors.lastname: Grainger
mesh_terms: D003500:Cyclization; D005609:Free Radicals / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013141:Spiro Compounds / Q000138:chemical synthesis; D013859:Thiocarbamates / Q000737:chemistry*; D014001:Tin / Q000737:chemistry; D047090:beta-Lactams / Q000138:chemical synthesis
chemical_list: D005609:Free Radicals; D013141:Spiro Compounds; D013859:Thiocarbamates; D047090:beta-Lactams; D014001:Tin