Nickel Hydroxo Complexes as Intermediates in Nickel-Catalyzed Suzuki-Miyaura Cross-Coupling

作者：Christian Alec H; Mueller Peter; Monfette Sebastien^*

来源：Organometallics, 2014, 33(9): 2134-2137.

DOI：10.1021/om5001327

The synthesis, characterization, and reactivity of intermediates formed in the Ni-catalyzed Suzuki-Miyaura cross-coupling (SMC) of an aryl chloride are described. Oxidative addition of 1-chloro-4-trifluoromethylbenzene (1) to a mixture of Ni(cod)(2) and PCy3 afforded NiCl(4-CF3Ph)(PCy3)(2) (2), which then cleanly provided dimeric [Ni(4-CF3Ph)(mu-OH)-(PCy3)](2) (3) by reaction with aqueous KOH. Reactivity studies of 2 and 3 with phenylboronic acid (4) revealed that, while 2 affords only traces of the biphenyl coupling product after 24 h, the same reaction with 3 is complete within minutes at room temperature. In contrast, the reaction of 3 with potassium phenyltrihydroxyborate (6) is much slower than that with boronic acid 4, and significantly lower yields of the cross-coupling product are obtained. We show that formation of the hydroxo species 3 is the rate-determining step in the present SMC.

• 出版日期2014-5-12
• 单位MIT