Peculiarities of Mercuration-Iododemercuration of Propargyl Derivatives

The mercuration-iododemercuration reactions of some propargyl systems were explored. In the presence of mercury (II) acetate, propargyl derivatives reacted facilely with iodine. These interactions proceeded by two possible pathways included corresponding bridged and linear organomercury intermediates. Short-chain alkyl propargyl ethers under mild conditions with mercury (II) acetate in an acetic acid (hexane or dichloromethane) medium with iodine resulted in a mixture of iodoalkyloxypropynes, diiodoalkyloxypropenyl acetates, diiodoalkyloxypropenes, and triiodoalkyloxypropenes. Acetoxymercuration-iododemercuration of the obtained reactive iodoalkynes occurred more rapidly than terminal alkynes. Hexyl, heptyl propargyl ethers studied reactions took place under heating, and the products were both unsaturated diiodoacetates and trans-monoiodoacetates in a mass ratio of approximately 1:1. Acetoxymercuration-iododemercuration of prop-2-yn-1-yl acetate in acetic acid at room temperature led to (E)-2,3-diiodoallyl acetate, diiododiacetate, and cis-, trans-monoiododiacetates. The researched reaction of propargyl alcohol in acetic acid at room temperature led to the mixture of triiodopropene and diiodopropene. The mercury (II) acetate-mediated iodination of 2-methylbut-3-yn-2-ol depends on the solvents nature and afforded corresponding mono-, di-, triiododerivatives. The mercuration-iododemercuration of 2-methylbut-3-yn-2-yl acetate in acetic acid at room temperature was special. This reaction result was the blend containing the product of triple bond indirect hydration and iodination of the methyl group, activated by the carbonyl.