Palladium catalysis Suzuki-Miyaura

The Suzuki-Miyaura synthesis is one of the most commonly used methods for the formation of carbon-to-carbon bonds [7]. As a palladium catalyst typically tetrakis(triphenylphosphine)palladium(0) has been used, giving yields of44—78%. Recently, Suzuki coupling between aryl halides and phenylboronic acid with efficient catalysis by palladacycles was reported to give yields of 83%. 

Shylesh, S., Wang, L. and Thiel, W.R. (2010) Palladium(II)-phosphine complexes supported on magnetic nanoparticles filtration-free, recyclable catalysts for Suzuki-Miyaura crosscoupling reactions. Advanced Synthesis and Catalysis, 352 (2-3), 425-432. 

Application of the complexes 63 in the Mizoroki-Heck reaction did not reveal higher activity than the previously examined palladium(II) complexes. However, in the Suzuki-Miyaura reaction, a drastically increased activity was observed with complex 63. Catalysis starts without a measurable induction period at mild temperatures accompanied by an extraordinarily high turnover frequency (TOF) of 552 [mol product x mol Pd x h ] at the start of the reaction for the coupling of p-chlorotoluene and phenyl boronic acid [Eq. (48)]. ... 

Phan NTS, Van Der Sluys M, Jones CW (2006) On the nature of the active species in palladium catalyzed Mizoroki-Heck and Suzuki-Miyaura couplings - homogeneous or heterogeneous catalysis, a critical review. Adv Synth Catal 348 609-679... 

A tandem Suzuki-Miyaura coupling/nucleophilic aromatic substitution to carba-zoles was developed by St. Jean et al. (Scheme 51) [210]. Reaction of A -sulfonyl-protected 2-aminophenylboronates 216 with l-bromo-2-fluorobenzenes 217 under palladium(0)-catalysis provides the Af-sulfonyl-protected carbazoles 218. This annulation is compatible with a variety of electron-withdrawing groups (e.g., aldehydes, esters, and sulfones) and has been applied to an efficient synthesis of glycosinine (147) (four steps, 50% overall yield). 

Palladium nanoparticles and other heterogeneous catalysts are often invoked as catalysts in cross-coupling processes [194, 195). Direct evidence in support of an oxidative-addition-promoted leaching mechanism has been recently obtained in the Suzuki-Miyaura reactions with nanoparticle catalysts, suggesting that true surface catalysis remains largely unknown with these heterogeneous catalysts [196]. 

To conclude this part of this section, we include an interesting study that was reported in 2012 by Ikawa et al. [141], in which phenols treated with nonafluorobutenesulfonyl fluoride (where Nf=S02(CF2)3CF3) underwent the Suzuki-Miyaura reaction in moderate yields under palladium catalysis (Pd(OAc)2 or Pd2(dba)3), using SPhos as the ligand and a weak base. The reaction proceeds through nonaflation of the phenols, that is, via an activated nonafluorobutanesulfonyl intermediate. 

The field of palladium catalysis is also progressing rapidly. The Tsuji-Trost and Mizoroki-Heck reactions have been mentioned earher, however other C-C coupling reactions (Miyaura-Suzuki, Sonogashira and Stille) are now extensively used in organic chemistry, and the search for non-polluting Sonogashira and Miyaura-Suzuki reactions is being actively pursued. 

M. Van der Sluys, C.W. Jones - On the Nature of the Active Species in Palladium Catalyzed Mizoroki-Heck and Suzuki-Miyaura Couplings- Homogeneous or Heterogeneous Catalysis, A Critical Review, Adv. Syn. Catal. 348,609, 2006. 

Sivudu, K.S., Reddy, N.M., Prasad, M.N., Raju, K.M., Mohan, Y.M., Yadav, J.S., Sabitha, G., Shailaja, D., 2008. Highly efficient and reusable hydrogel-supported nano-palladium catalyst evaluation for Suzuki—Miyaura reaction in water. Journal of Molecular Catalysis... 

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