In the last few years, we and other groups have demonstrated that economical cobalt salts can advantageously replace expensive and toxic catalysts for cross coupling reactions. These cobalt-catalyzed reactions have considerably extended the range of functionalized compounds. A variety of sensitive functional groups can be tolerated in these coupling reactions and various organic compounds RX could be involved (R = alkyl, alkynyl, aryl, allyl and X = halides: F, Cl, Br, I and even triflates). Here, we describe our contributions in this area for the preparation of a broad range of functionalized compounds from organometallic species or by direct cross-coupling.

Recently, Lewis acidic calcium salts bearing weakly coordinating anions such as Ca(NTf₂)₂, Ca(OTf)₂, CaF₂ and Ca[OCH(CF₃)₂]₂ have been discovered as catalysts for the transformation of alcohols, olefins and carbonyl compounds. High stability towards air and moisture, selectivity and high reactivity under mild reaction conditions render these catalysts a sustainable and mild alternative to transition metals, rare-earth metals or strong Brønsted acids.