The Hydride Transfer Nature of the Reduction of Carbonium Ions by HBr, HI and a Pt and an Ir Hydride

Reduction of benzylic alcohols and α-hydroxycarbonyl compounds by hydriodic acid in a biphasic reaction medium

“…The mechanistic details of the redox comproportionation of alkyl iodides and H–I have been strongly debated in the literature [36–38]. However, the required benzylic or α-carbonyl position for the redox comproportionation indicates an intermediate with mesomeric stabilization due to the adjacent π-system.…”

“…The mechanism of reduction by hydriodic acid consists of two steps ( Scheme 1 ): The nucleophilic substitution of the hydroxy group by iodide and the subsequent reduction of the alkyl iodide by hydriodic acid. The mechanistic details of the redox comproportionation of alkyl iodides and H–I have been strongly debated in the literature [ 36 – 38 ]. However, the required benzylic or α-carbonyl position for the redox comproportionation indicates an intermediate with mesomeric stabilization due to the adjacent π-system.…”

Reductive Deoxygenation of Alcohols: Catalytic Methods Beyond Barton–McCombie Deoxygenation

“…[70] The mechanism of this reduction consists of two steps: first, the hydroxy group is converted into the corresponding alkyl iodide, and second, the iodide is reduced by redox comproportionation with hydroiodic acid (Scheme 30). [71] In 1939, Miescher et al described the regeneration of HI from iodine by red phosphorus and the possibility of using iodine or iodide instead of hydroiodic acid. [71] In 1939, Miescher et al described the regeneration of HI from iodine by red phosphorus and the possibility of using iodine or iodide instead of hydroiodic acid.…”

“…Although nucleophilic substitution as the first step is widely accepted, the second step is controversially discussed in the literature. [71] In 1939, Miescher et al described the regeneration of HI from iodine by red phosphorus and the possibility of using iodine or iodide instead of hydroiodic acid. [72] Scheme 30.…”