2013 journal article

Cp*Ir-III-Catalyzed Oxidative Coupling of Benzoic Acids with Alkynes

ACS CATALYSIS, 3(10), 2421–2429.

By: D. Frasco n, C. Lilly n, P. Boyle n & E. Ison n

author keywords: C-H functionalization; oxidative coupling; C-H activation; Cp*Ir-III; annulation
Source: Web Of Science
Added: August 6, 2018

Cp*Ir(III) complexes have been shown to catalyze the oxidative coupling of benzoic acids with alkynes in methanol at 60 °C to form a variety of isocoumarins. The use of AgOAc as an oxidant was required to facilitate significant product formation. Alkyl alkynes were shown to be more reactive substrates than aryl alkynes, and a number of functional groups were tolerated on benzoic acid. Combined mechanistic and computational studies (BP86) revealed that (1) C–H activation occurs via an acetate-assisted mechanism; (2) C–H activation is not turnover limiting; and (3) the oxidant oxidizes the reduced form of the catalyst via an Ir(I)–Ir(II)–Ir(III) sequence.