N2-site-selective cross-couplings of tetrazoles with indoles

Abstract

A method for the site-selective cross-coupling of the N²-position of tetrazoles with indoles is reported. The in situ-generated N²-iodotetrazole intermediates are found to be critical for both activating indoles and achieving N²-selectivity. Upon reaction with indoles, heterolytic cleavage of the N²–I bond in N²-iodotetrazoles predominantly generates N²-localized anions. These anions subsequently attack iodonium ion intermediates, followed by a base-promoted in situ elimination step that affords the desired N²-coupling products. The reactions demonstrate a broad substrate scope, accommodating various tetrazoles and indoles, and are executed under mild conditions at room temperature, reaching completion within 5 minutes.