Transition Metal-like Oxidative Addition of C-F and C-O Bonds to an Aluminum(I) Center

Abstract

Oxidative addition of very robust C-F and C-O bonds has been accomplished in reactions of the aluminum(I) compound NacNacAl (1, NacNac = [ArNC(Me)CHC(Me)NAr]- and Ar = 2,6-Pri2C6H3) with fluoroarenes, fluoroalkanes, and ethers. Similar to the transition metals, the ease of aryl C-F oxidative addition decreases as the degree of fluorination diminishes on the aromatic substrate. As well, kinetic studies on the addition of 1,2,3,4-tetrafluorobenzene to compound 1 revealed a second-order reaction characterized by a very negative entropy of activation (ΔS‡ = -113.6(3) J/K·mol), consistent with a transition metal-like oxidative addition process.