Regiodivergent C-H alkynylation of 2-arylthiazoles switched by Ru II and Pd II catalysis.

Two complementary regiodivergent C-H alkynylations of 2-arylthiazoles are reported. When Ru II catalysis is employed, an aryl ortho -alkynylation process is favored. The alkynylated products are gained in good yields. With the use of Pd II catalysis, a thiazole C5-alkynylation process is developed, allowing for the construction of C5-alkynylated products. This strategy not only expands the methods for the functionalization of 2-arylthiazoles, but also provides new opportunities for the rapid assembly of complex molecular structures, which may have great potential in organic synthesis, medicinal chemistry, and materials science.