Selective oxidative β-C-H bond sulfenylation of tetrahydroisoquinolines with elemental sulfur.

In this article, a convenient and efficient KIO-promoted oxidative sulfenylation at the β-position of tetrahydroisoquinolines and subsequent aromatization in the presence of elemental S is presented. The reaction proceeds with moderate to good yields a double C-S formation process. A wide range of structurally diverse 4-sulfenylisoquinolines/3-sulfenylpiperidine were synthesized with excellent functional group tolerance and high efficiency.