Oxidative addition of aryl electrophiles to a prototypical Nickel(0) complex: Mechanism and structure/reactivity relationships

Abstract

The interest in nickel complexes which are able to achieve cross-coupling reactions is increasing in recent years due to their potential as an alternative to more expensive palladium catalysts. In spite of this, there are relatively few mechanistic studies of Ni based precatalysts, and it is often assumed that the reactivity of nickel systems is similar to that of their palladium analogues. This fact makes improvements in the design of new systems more challenging. In this context, we have explored the rates at which a relevant Ni0 complex ((dppf)Ni(cod) (cod = 1,5-cyclooctadiene; dppf = 1,1´-bis (diphenylphosphino)ferrocene) undergoes oxidative addition with different electrophiles, and the selectivity of these oxidative addition reactions. In addition, we have studied the interaction of this nickel fragment with several functional groups that are present in synthetic chemistry targets. Together, this is allowing us to build a quantitative picture of the processes that take place in nickelcatalysed reactions.