Rapid preparation of triazolyl substituted NH-heterocyclic kinase inhibitors via one-pot Sonogashira coupling-TMS-deprotection-CuAAC sequence.

The one-pot, three-component Sonogashira coupling-TMS-deprotection-CuAAC ("click") sequence is the key reaction for the rapid synthesis of triazolyl substituted N-Boc protected NH-heterocycles, such as indole, indazole, 4-, 5-, 6-, and 7-azaindoles, 4,7-diazaindole, 7-deazapurines, pyrrole, pyrazole, and imidazole. Subsequently, the protective group was readily removed to give the corresponding triazolyl derivatives of these tremendously important NH-heterocycles. All compounds have been tested in a broad panel of kinase assays. Several compounds, 8f, 8h, 8k, and 8l, have been shown to inhibit the kinase PDK1, a target with high oncology relevance, and thus they are promising lead structures for the development of more active derivatives. The X-ray structure analysis of compound 8f in complex with PDK1 has revealed the detailed binding mode of the molecule in the kinase.