Suzuki advantages

Nickel can also be used in place of Pd in Suzuki-type couplings of boronic acids. The main advantage of nickel in this application is that it reacts more readily with aryl chlorides275 and methanesulfonates276 than do the Pd systems. These reactants may be more economical than iodides or triflates in large-scale syntheses. 

In addition, arylthiophene 70 was obtained by a one-pot Suzuki coupling of p-methoxyiodobenzene and 3-bromothiophene via an in situ boronate formation using one equivalent of the thermally stable diborane 69 [55], This method avoids the isolation of boronic acids and is advantageous when base-sensitive groups such as aldehyde, nitriles and esters are present. However, the cross-coupling yields are low when both aryl halides are electron-poor because of competitive homocoupling during the reaction. 

Dense metallic membranes have the advantage of very high selectivities since only certain species can be dissolved in their structural lattice. However, the permeabilities are lower by a factor of 100 than those of porous membranes (Ilias and Govind 1989, van Vuren et al. 1987, Itoh 1987, Suzuki, Onozato and Kurokawa 1987). For example, the permeability of... 

Since the Suzuki coupling of purine derivatives was covered by recent reviews,1 we only present a selection lfom these reactions. Xanthine (3,6-dihydropurine-2,6-dione) derivatives were coupled with different boronic acids, including styrylboronic acid, in the presence of the conventional tetrakis(triphenylphosphino)palladium catalyst and tripotassium phosphate as a mild base (8.1.), to obtain the appropriate 8-substituted xanthines in acceptable yield.4 The advantage of the use of anhydrous tripotassium phosphate as base over the classical aqueous carbonate or hydroxide reagents might be attributed to the sensitivity of the 8-halopurine core towards nucleophilic attack. 

O-acylation, O-sulfanylation, O-triflation/Suzuki coupling followed by N-quaternization (six inputs) and Hofmann elimination to release a 3,042-member library of tertiary amino aryls. One advantage of small-molecule nonoligomeric libraries... 

A major advantage of this MCR is that organoboronic acids are readily available in a large variety of structural configurations and they can be formed in isomeri-cally pure forms. As a result of their widespread utility in Suzuki-Miyaura coupling [27, 28] and other reactions [29, 30], a variety of aryl and heteroaryl [31] boronic adds are now commercially available and can be employed in this MCR process. Most of these compounds are also air and water stable as well as non-toxic and environmentally friendly. They also tolerate many functional groups, thereby... 

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