Facile Access to 2-Substituted Benzoxazoles Using Sawdust Supported N-Heterocyclic Carbene-Ni Complex via C-H Activation

Sawdust supported N-heterocyclic carbene-nickel complex has been prepared by covalent grafting of 1-methyl imidazole in the matrix of chloropropyl modified sawdust followed by reaction with nickel acetate. The resultant NHC-Ni complex was employed as a heterogeneous catalyst for the synthesis of 2-substituted benzoxazoles from benzoxazole and aryl boronic acids following C-H activation strategy. The recycling experiments showed that the complex could be reused for five consecutive runs without significant loss in the yield of products.