Tunable Regiodivergent C–H Alkenylation of 2-Arylthiazoles via Catalyst Control

We have developed a novel and efficient Pd(II)- and Ru(II)-catalyzed switchable C-H alkenylation of 2-arylthiazoles with alkenes, achieving high levels of regio- and stereoselectivity. This protocol enables the selective synthesis of either C5- or ortho-alkenylated products, depending on the choice of metal catalyst. The reactions involve two distinct pathways: ortho-alkenylation proceeds via chelation-assisted ruthenation, while C5-alkenylation occurs through electrophilic palladation. This regiodivergent strategy offers a versatile approach for the direct construction of π-extended 2-arylthiazole derivatives, which show promising potential for applications in medicinal chemistry and materials science.