title: Thiazine-2-thiones as Masked 1-Azadienes in Cascade Dimerization Reactions).
abstract: We report the unexpected formation of a 1-azadiene dimer from 4,6-diphenyl-3,6-dihydro-2H-1,3-thiazine-2-thiones under prolonged microwave irradiation. In this manner, thiazine-2-thiones act as "masked" 1-azadiene equivalents, which makes them useful synthetic tools to access complex heterocyclic frameworks. We compare this dimerization with earlier approaches and elaborate on the observed diastereoselectivity.
authors.affiliation: Department of Chemistry & Pharmaceutical Sciences and Amsterdam Institute for Molecules, Medicines & Systems, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081HZ Amsterdam, The Netherlands. a.kruithof@vu.nl.
authors.forename: Art
authors.initials: A
authors.lastname: Kruithof
authors.affiliation: Faculty of Applied Engineering, Advanced eactor Technology, University of Antwerp, Groenenborgerlaan 171, 2018 Antwerpen, Belgium. christophe.vandevelde@uantwerpen.be.
authors.forename: Christophe M L
authors.initials: CM
authors.lastname: Vande Velde
authors.affiliation: Department of Chemistry & Pharmaceutical Sciences and Amsterdam Institute for Molecules, Medicines & Systems, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081HZ Amsterdam, The Netherlands. e.ruijter@vu.nl.
authors.forename: Eelco
authors.initials: E
authors.lastname: Ruijter
authors.affiliation: Department of Chemistry & Pharmaceutical Sciences and Amsterdam Institute for Molecules, Medicines & Systems, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081HZ Amsterdam, The Netherlands. r.v.a.orru@vu.nl.
authors.forename: Romano V A
authors.initials: RV
authors.lastname: Orru
mesh_terms: D001372:Aza Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D019281:Dimerization; D008872:Microwaves; D015394:Molecular Structure; D013237:Stereoisomerism; D013843:Thiazines / Q000737:chemistry*; D013871:Thiones / Q000737:chemistry*
chemical_list: D001372:Aza Compounds; D013843:Thiazines; D013871:Thiones
keywords: 1-azadienes; aza-Diels-Alder; chemical space; microwave; molecular diversity; multicomponent reaction; tetrahydropyrimidines; thiazine-2-thiones