Zeng J, Liu KM, Duan XF * Beijing Normal University, P. R. of China
Selective Co/Ti Cooperatively Catalyzed Biaryl Couplings of Aryl Halides with Aryl Metal Reagents.
Org. Lett. 2013;
15: 5342-5345
Key words
cobalt - titanium - cooperative catalysis
Significance
A novel method for cobalt-catalyzed cross-coupling reactions between aryl chlorides or bromides and aromatic magnesium or lithium reagents is reported by Duan and co-workers. The presence of 40 mol% of Ti(OEt)4 suppresses undesired homocoupling side-products resulting from the organometallic reagent.
Comment
Interestingly, the reaction can also take place in the presence of a free carboxylic acid, a hydroxyl, or an amide residue. Therefore, this protocol allows an efficient arylation of highly functionalized aryl halides without protection–deprotection sequences.
