Bimetallic Oxidative Addition in Nickel-Catalyzed Alkyl–Aryl Kumada Coupling Reactions

Bimetallic oxidative addition involving radical intermediates in nickel-catalyzed alkyl-alkyl Kumada coupling reactions.

Many nickel-based catalysts have been reported for cross-coupling reactions of nonactivated alkyl halides. The mechanistic understanding of these reactions is still primitive. Here we report a mechanistic study of alkyl-alkyl Kumada coupling catalyzed by a preformed nickel(II) pincer complex ([(N2N)Ni-Cl]). The coupling proceeds through a radical process, involving two nickel centers for the ox...

Cooperative bimetallic oxidative addition reactions*

The factors that control the oxidation of metals in bimetallic complexes are investigated in relation to the possibility of developing one-site addition two-metal oxidation reactions such as those that occur in the respiratory protein, hemerythrin. It is shown that the behavior of bimetallic complexes is not represented by the sum of the analogous monometallic parts because of metal and ligand ...

Nickel-Catalyzed Coupling Reactions of Alkenes.

Several reactions of simple, unactivated alkenes with electrophiles under nickel(0) catalysis are discussed. The coupling of olefins with aldehydes and silyl triflates provides allylic or homoallylic alcohol derivatives, depending on the supporting ligands and, to a lesser extent, the substrates employed. Reaction of alkenes with isocyanates yields N-alkyl acrylamides. In these methods, alkenes...

Nickel (0) Catalyzed Kumada Chain Transfer Polycondensation

Gold-catalyzed oxidative coupling reactions with aryltrimethylsilanes.

During continuing studies with a novel oxidative gold oxyarylation reaction, arylsilanes were found to be competent coupling partners, providing further evidence for an intramolecular electrophilic aromatic substitution mechanism. While providing yields complementary to those of the previously described boronic acid methods, the use of trimethylsilanes reduces the observation of homocoupling by...