Sulfide-Directed Ir-Catalyzed Vinylic sp2 and Benzylic sp3 C-H Activation for the Construction of Sulfur-Containing Medium-Ring System

Abstract

Ir-catalyzed transformations initiated by sulfur-directed vinylic sp² and benzylic sp³ C-H activation are disclosed that achieve the construction of sulfur-containing seven- and eight-membered systems. Allyl 2-alkynylphenyl sulfides were transformed into dihydrobenzothiepines in 30-95 % yield, and 2-alkynylaryl 2-tolyl sulfides were converted into dibenzo[b,f]thiepines in 57-95 % yield along with double bond isomerization. In both reactions, the combination of Ir catalyst and sulfide moiety was a key to the facile cyclization.

Keywords: C−H activation; directing group; iridium; medium ring system; sulfide.