Ruthenium(II)-catalyzed direct addition of indole/pyrrole C2-H bonds to alkynes.J Org Chem. 2014 Oct 17; 79(20):9472-80.JO
A ruthenium-catalyzed C2-hydroindolation of alkynes has been achieved. This protocol provides a rapid and concise access to kinds of 2-alkenyl-substituted N-(2-pyridyl)indoles in which the pyridyl moiety can be easily removed to afford free (N-H) indoles under mild conditions. Various arenes and alkynes, including electron-deficient and electron-rich internal alkynes and terminal alkynes, allow for this transformation.