iophenols

Iophenols, or iodophenols, are aromatic compounds in which one iodine atom is bonded to a phenolic ring. The simplest members are 2-iodophenol, 3-iodophenol, and 4-iodophenol; polyiodinated variants are also known. The hydroxyl group of the phenol activates the ring toward electrophilic substitution and directs new substituents to the ortho and para positions; the C–I bond provides a reactive handle for subsequent transformations, especially palladium-catalyzed cross-couplings.

Iodophenols are typically prepared by electrophilic iodination of phenols using iodine in the presence of an oxidant (for example, hydrogen peroxide, periodic acid, or iodic acid) or by iodine transfer reagents such as N-iodosuccinimide. Regioselectivity follows the directing effect of the hydroxyl group, with ortho and para products common, though steric effects can influence the outcome.

In chemical synthesis, the aryl iodide moiety is a versatile leaving group in cross-coupling and other metal-catalyzed processes, enabling rapid assembly of substituted aromatics, biaryl motifs, and polyfunctional materials. The phenolic OH can be protected or converted to a phenoxide, which can affect coupling conditions.

Iodophenols serve as intermediates in pharmaceutical synthesis, agrochemicals, dyes, and organic materials.

They are corrosive and potentially toxic; handle with appropriate PPE and dispose of waste according to regulations.