Remote copper-catalyzed enantioselective substitution of yne-thiophene carbonates

Here, we describe a strategy for the copper-catalyzed asymmetric heteroarylation of yne-thiophene carbonates with indoles via remote substitution. The key to the success of this strategy lies in the design of the alkynyl group at the ortho-position of the heterocycle thiophene, enabling the formation of a triarylmethane moiety via very remote substitution. Thus, the concept of remote copper-catalyzed asymmetric transformation extends not only to yne-allylic esters but also to yne-aryl esters. The reaction readily provides a diverse array of chiral triarylmethanes with high efficiency, enantioselectivity, and excellent functional group compatibility. Moreover, facile follow-up transformations underscore their potential utility in the synthesis of various enantioenriched building blocks. Preliminary mechanistic studies support the plausibility of the remote substitution pathway.