Grindstone chemistry: (diacetoxyiodo)benzene-mediated oxidative nuclear halogenation of arenes using NaCl, NaBr or I₂

Abstract

A technique of "Grindstone chemistry" is applied to the solvent-free halogenation of arenes with NaCl, NaBr or I 2 using (diacetoxyiodo)benzene as the oxidant. Improved yields and higher purities of the products are observed compared with those from established methods.

Short-Step Synthesis of a Resveratrol Derivative from Commercially Available 1,3-Dimethoxybenzene and 4-Vinylanisole

“…12) [Ir(COD)(OMe)] 2 (9.3 mg, 14 mmol), dtbpy (8 mg, 30 mmol), and B 2 pin 2 (406 mg, 1.6 mmol) were combined in a Schlenk tube that was evacuated and refilled three times with argon. Under a positive flow of argon, dry THF (3.0 ml) and 1,3-dimethoxybenzene (276 mg, 2.0 mmol) were added.…”

“…This method is useful for a large-scale preparation and can be applied to synthesize some precursors for cross-coupling methods applicable to the synthesis of various natural products. We attempted to synthesize 2 by using the Sandmyer reaction from 3,5-dimethoxyaniline with CuBr and HBr, 11) (deacetoxyiodo)benzene-mediated oxidative nuclear halogenation of arene developed by Karade et al,12) and 3,5-dimethoxylation of 1,3,5-tribromobenzene by using NaOMe. 13) However, in all cases, our achieved yield of 2 was very poor.…”

Introduction of Halogen Atoms into Organic Compounds Under Solvent- Free Reaction Conditions

“…Vapour phase aerobic bromination of aromatic compounds using the HBr/O 2 system is usually performed in the presence of a catalysts containing an oxidizing metal and an inert support [108], but these systems exceed the scope of this account. The tandem of NaBr/(diacetoxyiodo)benzene was successfully used for room temperature bromination of activated benzene derivatives (B106, Scheme B26) and the formation of para brominated products was established [68], while the transformation of 2-methoxynaphthalene B108 gave 87% of 1-brominated product B109 [68].…”

“…Ring chlorination of arenes (C43) by the system NaCl and (diacetoxyiodo)benzene (DIB) as oxidizer in 1 : 1 : 1.1 ratio was performed and after 30 minutes of trituration monochlorosubstituted products C44 were isolated in good to excellent yields (Scheme C10) [68]. The silica supported hydrogen chloride/iodosobenzene system was also used as a source of the chlorine atom.…”

“…and UREA-hydrogen peroxide (UHP) [111] or (diacetoxyiodo)benzene (DIB) [68,117] this way aniline derivatives I13 were iodinated at the para position (I14) and various anisol (I15) and xylene derivatives were also functionalised efficiently.…”