1160553-69-4Relevant articles and documents
Easily attachable and detachable ortho-directing agent for arylboronic acids in ruthenium-catalyzed aromatic C-H silylation
Ihara, Hideki,Suginome, Michinori
supporting information; experimental part, p. 7502 - 7503 (2009/10/16)
(Chemical Equation Presented) o-C?H silylation of arylboronic acids has been achieved using 2-pyrazol-5-ylaniline as an orthodirecting agent, which was temporarily attached to the boronyl group via Ru-catalyzed silylation with hydrosilanes. Condensation products of arylboronic acids with2-pyrazol-5-ylaniline were prepared in situ and subjected to reaction w ith triorganosilanes in the presence of RuH2(CO)(PPh3) 3 at 135°C. Regioselective silylation at their ortho-positions proceeded in good yields for phenylboronic acids bearing para-substituents such as chloro, fluoro, methyl, methoxy, and trifluoromethyl groups. p-Methoxycarbonyl-substituted phenylboronic acid provided thecorresponding silylated product in moderate yield. m-Tolyl- and 2-napht hylboronic acids underwent silylation selectively at the less stericallyhindered ortho-positions. The silylated products were utilized in Suzuk i?Miyaura coupling, followed either by iodination with ICl or by Tamao oxidation to furnish iodine- or hydroxy-substituted biaryls.
