Carboxylate-directed C-H allylation with allyl alcohols or ethers.

A [Ru(p-cymene)Cl2]2 catalyst activates allyl alcohols and ethers for the regioselective ortho-C-H allylation of aromatic and heteroaromatic carboxylates. The reaction is orthogonal to most C-H functionalisations with allyl alcohols in that allyl arenes rather than carbonyl compounds are obtained. A wide range of substrates are thus smoothly transformed to allylarenes at 50 °C in phosphate-buffered 2,2,2-trichloroethanol. The reaction concept combines the use of abundant reagents and directing groups in a sustainable, waste-minimised method for C-C bond formation.

Regiospecific ortho-C-H Allylation of Benzoic Acids.

A carboxylate-directed ortho-C-H functionalization has been developed and it allows the regiospecific introduction of allyl residues to benzoic acids. In the presence of a [Ru(p-cymene)Cl2 ]2 and K3 PO4 , benzoic acids react with allyl acetates at only 50 °C to give the corresponding ortho-allylbenzoic acids. The protocol is generally applicable to both electron-rich and electron-poor benzoic acids in combination with linear and branched allyl acetates. The products can be further functionalized in situ, for example, by double-bond migration, lactonization, or decarboxylation.