Catalyst-transfer Suzuki-Miyaura coupling

T. Yokozawa, R. Suzuki, M. Nojima, Y. Ohta, A. Yokoyama, Precision Synthesis of Poly(3-Hexylthiophene) from Catalyst-Transfer Suzuki-Miyaura Coupling Polymerization. Macromol. Rapid Commun. 2011,32,801-806. 

Scheme 49 Catalyst-transfer Suzuki-Miyaura coupling polymerization of 41...

Yokozawa T, Suzuki R, Nojima M, Ohta Y, Yokoyama A (2011) Fhecision synthesis of poly (3-hexylthiophene) from catalyst-transfer Suzuki-Miyaura coupling polymerization. Macromol Rapid Commun 32 801-806... 

The highly reactive catalyst [PdPtBUa] can be generated by fast 1 1 micromixing of [Pd(OAc)2] and PtBUa and can be quickly transferred to the reaction vessel using a flow system to perform the Suzuki-Miyaura couplings [164]. 

Anionic complexes of boron (boronates, borinates, etc.) have been introduced as convenient reagents in cross-coupling reactions of broad scope, particularly interesting for the transfer of alkynyl and primary alkyl residues, which cannot be accomplished using the standard protocols of the Suzuki-Miyaura reaction. Readily available Ph4BNa can be used as a convenient reagent for phenylation in place of the much more expensive PhB(OH)2, and all four phenyl groups can be utilized when the reaction is carried out with a phosphine-free catalyst in aqueous solutions.244... 

Bedford and coworkers disclosed iron-catalyzed Suzuki-Miyaura-type coupling reactions of benzyl bromides with sodium tetraphenylborate in the presence of 5 mol% 15 as the catalyst and 10 mol% of dianisylzinc as a promoter. No reaction occurred in its absence. The coupling furnished 38-88% yield of 3 (entry 26) [66]. The transformation proceeds probably by initial B-Zn transmetalation. The resulting arylzinc transfers the aryl group to the iron catalyst as in the Negishi couplings above. An aryliron(I) complex was proposed to be formed initially. 

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