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

Thio-directed sp² and sp³  C−H activation is a new strategy for the construction of a sulfur-containing medium-ring system. Cationic Ir-catalyzed intramolecular hydroarylation to alkynes gave dihydrobenzothiepines and dibenzo[b,f]thiepines.

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.

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