Activation of sp3 and sp2 C[sbnd]H bonds of oxygen containing heterocyclic molecules for alkylation and arylation reactions catalyzed by an iron complex

Abstract

Activation of both sp3 and sp2 CH bonds is reported using an efficient iron(III) complex (1) of a ligand (N2,N6-bis(2,6-diisopropylphenyl)pyridine-2,6-dicarboxamide: L). The iron(III) complex showed catalytic activity of CC coupling reaction of oxygen containing heterocycles, e.g. tetrahydrofuran (THF), with various alkyl, allyl and aryl Grignard reagents under ambient reaction conditions. Complex 1 demonstrated excellent activity and reactions were completed within 30min to 1h. A high turnover frequency (TOF) of 1700h−1 using a low catalyst loading of 0.02mol% was obtained for the reaction. Interestingly, the catalyst was selective in activation of the CH bond adjacent to the oxygen in various oxygen containing heterocyclic molecules to yield 2-substitituted products.