Suzuki method

K. Tamura and S. Suzuki, Method for producing (meth)allyl (methacrylate, JP Patent 2 005 314 248, assigned to Mitsubishi Rayon Co. and Osaka Organic Chem. Ind., November 10, 2005. 

Title Modified Suzuki-Method for Polymerization of Aromatic Monomers... 

Like hydroalumination and hydrozirconation, hydroboration of alkynes also provides a convenient and Stereospecific route to alkenyl metal reagents. However, initial attempts to achieve palladium-catalyzed cross-coupling of alkenylboranes with alkenyl halides were unsuccessful, due to the poor carbanionic character of these reagents. Later, Suzuki discovered that the desired transformation could be effected in the presence of an alkoxide or hydroxide base weaker bases, such as sodium acetate or triethylamine, were not generally effective. The reaction is suitable for the preparation of ( , )-, ( ,Z)- and (Z,Z)-dienes. Since reactions of alkenylboronates are higher yielding than those of alkenylboranes, the recent availability of (Z)-l-alkenylboronates " substantially improves the Suzuki method for the preparation of (Z)-alkenes. An extension of the methodology to the synthesis of trisubstituted alkenes has also been reported. " ... 

Boron-substituted pyridine reagents can be used to construct the bipyridine ring system by coupling them with halopyridines in the presence of a Pd° catalyst and a base (Suzuki method). Various ligands have been made in this manner in moderate to high yields, including 2,3-bipyridine (85%)41 and 3,5-dimethyl bipyridine (60%) 42 One valuable feature of the Suzuki method is that it is compatible with stannanes. A pyridyl diethylborane has been coupled to a tributyl tin-functionalized pyridyl bromide.43 This compatibility is useful for polypyridine syntheses because subsequent Stille coupling of the bipyridyl stannane is possible. 

Benzylfluoropyrazines have been used as building blocks to synthesize a wide range of arylbenzylfluoropyrazines, which exhibit mesomeric properties. Alkyl or arylbenzyl-fluoropyrazines 23 were conveniently prepared from iodofluorobenzylpyrazines (22) via arylation by Suzuki method [19] or alkylation under the Negishi conditions [17]. 

The Suzuki method for cross-coupling involves use of an arylboronic acid as the nucleophilic component. These conditions have been successfully applied to indoles. Indole-3-boronic acids, which can be prepared via electrophilic mercuration, can be coupled with vinyl triflates (Scheme 130) <93TL2235>. 

Eigenvalues for the T = 1 and T = 0 systems obtained with the Lee-Suzuki method after four iterations ... 

Method A (McCullough), Method B (RIeke), Method C (GRIM), Method D (Stille), Method E (FeCIs), Method F (Suzuki) Method C (post-functionallzation) Method H (Ullmann). 

Scheme 18.20 Suzuki method to prepare aryl oxetanes.

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