Related Experiment Video
Updated: Aug 20, 2026

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions
Published on: October 5, 2019
Ring-opening of unsymmetrical 1,2-dioxines using cobalt(II) salen complexes
Ben W Greatrex1, Dennis K Taylor
1Department of Chemistry, University of Adelaide, South Australia, 5005.
Abstract:
The regioselectivity of the metal-catalyzed ring opening of unsymmetrical 1,2-dioxines to cis-gamma-hydroxyenones was investigated using two different Co(II) salen complexes. Regioselectivity was determined by direct examination of the enone ratios and by derivitization with a stabilized phosphorus ylide. The steric influence of the substituents on the 1,2-dioxine was the primary influence on regioselectivity. Temperature played little role; however, solvent and selection of Co(II) complex could be used to mildly influence the outcome of the rearrangement for selected substrates. The origins of the selectivity for the reaction are discussed.
Related Concept Videos
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Base-Catalyzed Ring-Opening of Epoxides
Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids

