Copper oxidative annulations with

Disubstituted isocoumarins arise from the copper(II)-catalyzed addition of o-halobenzoic acids to active internal alkynes (13JOC1660), rhodium(III)-mediated oxidative coupling ofbenzoic acids with disubsti-tuted alkynes (13T4454), palladium(II)-catalyzed tandem annulation reaction of o-alkynylbenzoates with methyl vinyl ketone (13T8626), and nickel(II)-promoted t-butyl isocyanide insertion in 2-(o-bromophenyl)-1-ethanones followed by hydrolysis (Scheme 69) (13SC3262). 

The coupling of triphenylmethanols with internal alkynes proceeds in a 1 2 maimer in the presence of a rhodium catalyst and a copper salt oxidant to afford annulated products, tetra-substituted naphthalenes (Scheme 4.98) [97]. The cat-alytically active species is considered to be a Rh(III) complex generated in the medium. 

In 2008, Fagnou et al. reported that acetanilide couples with alkynes in the presence of a Cp Rh catalyst and a copper salt oxidant through ortho C—H bond cleavage to produce Al-acetylindole derivatives [Eq. (a) in Scheme 25.36] [28a]. In contrast, the authors found that benzanilide, which possesses two types of cleavable ortho C—H bonds on anilino and benzoyl moieties, undergoes annulation accompanied by the selective cleavage of the benzoyl C—H bond to give isoquinolinone derivatives [Eq. b] [20]. 

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