Suzuki-Type Cross-Couplings

The more utilitarian means for installing an aryl substituent in position 4 onto the 2(5//)-furanone ring, the Suzuki-type cross-coupling of arylboronic acid with... 

The authors used a synthesis of 9,9-spirobitluorenes 32 which was developed by Clarksen and Gomberg [60] and which includes the addition of biphenyl-2-yl-magnesium iodide to fluorenone and subsequent cyclization with protic acids. To obtain 2,2,, 7,7 -arylated 9,9-spirobifluorenes 33, 9,9-spirobifluorene (32) was tetrabrominated [58] to yield 34 followed by a Suzuki-type aryl-aryl cross-coupling with various oligoaryl and oligoheteroaryl boronic acids to obtain the 2,2, 7,7 -tetraarylated derivatives 33. 

A drawback of the Heck-type reaction is that it is not strictly regioselective [119]. Depending on the substituents >1% of 1,1-diarylation is observed. Soluble 2,5-dialkoxy-PPVs 63 or 2-phenyl-PPV PPPV 93, without 1,1-diarylated moieties, were synthesized by Heitz et al. in a Suzuki-type cross coupling of substituted 1,4-phenylenediboronic acids and fran5-l,2-dibromoethylene, catalyzed by Pd(0) compounds [120]. However, about 3% of biaryl defect structures are observed in the coupling products (M up to 12,000), resulting from homocoupling of boronic acid functions. 

In 1996, Wegner et al. published the synthesis of poly(oligophenylenevinyle-ne)s (96), consisting of biphenylene-, terphenylene- and quinquephenylene moieties as aromatic building blocks, via Suzuki-type aryl-aryl cross coupling of AA/BB-type monomers [121]. By judicious choice of the arylene moieties, the optical properties of the resulting polymers can be tailored within a wide range. 

The scope of Suzuki-Miyaura reactions is extremely broad, covering practically all types of organic residues. The cross-coupling of arylboronic acids with aryl halides or triflates is the most... 

Other successful examples of catalysts containing NHC ligands are found in palladium- and nickel-catalyzed carbon-carbon bond formations. The catalyst development with these metals has focused in particular on Heck-type reactions, especially the Mizoroki-Heck reaction itself [Eq. (42)] and various cross coupling reactions [Eq. (43)], e.g., the Suzuki-Miyaura reaction ([M] = and the Kumada-Corriu reaction ([M] = MgBr). " Related reactions like the Sonogashira coupling [Eq. (44)]326-329 Buchwald-... 

Hartwig-Buchwald, Suzuki, and Stille type cross-coupling reactions with key intermediate 46 led to a wide range of substituted sulfoximines such as 47-49 [37]. In order to demonstrate the synthetic utility of the resulting products, pseudo tripeptide 50 was prepared from a related intermediate. 

R = Bu, CH(Oa>2, CH(OAc)CHj Figure 20 Suzuki-type cross coupling reaction. 

Chen, H. Deng, M.-Z. A novel Suzuki-type cross-coupling reaction of cyclopropylboronic esters with benzyl bromides./. Chem. Soc. Perkin Trans. 1 2000, 1609-1613. 

Recently we have reported a preliminary communication on Suzuki—Miyaura type of cross-coupling of 6-... 

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