Abstract
-Hydroxysulfides comprise a significant segment of sulfur-containing natural products. Owing to their biological importance, their presence in a number of natural products in addition to their use as key intermediates in the synthesis of pharmaceuticals and substrates for the preparation of allylic alcohols, benzoxathiepines, benzodiazepines, thioketones, -substituted unsaturated enones, and -hydroxysulfoxides [15b], a number of methodologies have been reported for the synthesis of β-hydroxysulfides. Regioselective epoxide ring opening and 1,2-difunctionalization of alkenes are the commonly employed routes in the synthesis of such compounds. However, most of the reported methods suffer from one or more limitations including the use of transition metals, poor regioselectivity, long reaction times, limited substrate scope, the need for expensive and toxic reagents as well as the need for the preparation of an epoxide precursor and the formation of undesirable side products via rearrangement of epoxides and the oxidation of thiols, especially in the thiolysis of epoxides. In addressing some of these issues, we herein report in the current study a transition metal-free iodine catalysed preparation of acetate masked -hydroxysulfides (-acetoxysulfides) in the presence of a disulfide and a diacetoxyiodobenzene. The scope and limitations of the methodology are investigated in detail.
In demonstrating the importance of (-acetoxysulfides) in organic synthesis, the methodology was fine tuned to provide styrene dimers that incorporate a sulfur heteroatom via a head-to-tail dimerization. The importance of sulfur in the synthesis of advanced materials, the scarcity of methodologies for the incorporation of sulfur to styrene monomers, as well as the attractiveness of the head-to-tail dimerization which generates an allylic chiral centre that is reported to be present in a number of biologically important organic molecules, makes the current method attractive in organic synthesis and thus, the results from the investigation of the scope and limitations of the reaction are reported along with full experimental details.
M.Sc. (Chemistry)