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Suzuki reaction
The Suzuki reaction is the organic reaction that is classified as a coupling reaction where the coupling partners are a boronic acid with a halide catalyzed by a palladium(0) complex. It was first published in 1979 by Akira Suzuki and he shared the 2010 Nobel Prize in Chemistry with Richard F. Heck and Ei-ichi Negishi for their effort for discovery and development of palladium-catalyzed cross couplings in organic synthesis. In many publications this reaction also goes by the name Suzuki–Miyaura reaction and is also referred to as the "Suzuki Coupling". It is widely used to synthesize poly-olefins, styrenes, and substituted biphenyls. Several reviews have been published describing advancements and the development of the Suzuki Reaction.〔(Review)〕 The general scheme for the Suzuki reaction is shown below where a carbon-carbon single bond is formed by coupling a organoboron species (R1-BY2) with a halide (R2-X) using a palladium catalyst and a base.
==Reaction mechanism==
The mechanism of the Suzuki reaction is best viewed from the perspective of the palladium catalyst. The first step is the oxidative addition of palladium to the halide 2 to form the organopalladium species 3. Reaction with base gives intermediate 4, which via transmetalation〔Matos, K.; Soderquist, J. A. ''J. Org. Chem.'' 1998, ''63'', 461–470. ()〕 with the boron-ate complex 6 (produced by reaction of the boronic acid 5 with base) forms the organopalladium species 8. Reductive elimination of the desired product 9 restores the original palladium catalyst 1 which completes the catalytic cycle. The Suzuki coupling takes place in the presence of a base and for a long time the role of the base was never fully understood. The base was first believed to form a trialkyl borate (R3B-OR), in the case of a reaction of an trialkylborane (BR3) and alkoxide (−OR); this species could be considered as being more nucleophilic and then more reactive towards the palladium complex present in the transmetalation step.〔 Duc and coworkers investigated the role of the base in the reaction mechanism for the Suzuki coupling and they found that the base has three roles: Formation of the palladium complex (), formation of the trialkyl borate and the acceleration of the reductive elimination step by reaction of the alkoxide with the palladium complex.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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