Science of Synthesis

Hopkinson, M. N.; Gouverneur, V., Science of Synthesis Knowledge Updates, (2011) 2, 116.

The use of the hypervalent iodine(III) reagent (diacetoxyiodo)benzene enables the catalytic synthesis of biaryl compounds directly from nonactivated arenes with gold(III).[‌65‌] This synthesis, developed by Tse and co-workers, has potential as a powerful alternative to the Suzuki reaction as a route to these important compounds. Unlike the Suzuki coupling between aryl halides and arylboronic acids, this approach does not require preactivation of the starting materials. Upon treatment with 2 mol% of tetrachlo­roauric acid (HAuCl4) in the presence of (diacetoxyiodo)benzene, a range of arenes ‌34‌ can be successfully homocoupled to afford the corresponding biaryls ‌35‌ via aryl C(sp2)–H bond functionalization (‌Scheme 15‌). Alternative oxidants such as potassium peroxydisulfate (K2S2O8), Oxone, and copper(II) acetate are not suitable in this transformation, whereas no biaryls are formed using alternative transition-metal catalysts. The reaction proceeds in moderate to high yields relative to the oxidant and is tolerant of a wide range of functional groups, including halogens. Notably the process is not sensitive to water or oxygen and can be performed under ambient conditions.

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References