Rapid metal free construction of 3-positioned 2-pyridyl substituent in indoles

New access to substituted 2-(indol-3-yl)pyridines involves two stage protocol, namely, a reaction of deoxygenative nucleophilic substitution of hydrogen in 1,2,4-triazine-4-oxides under the action of indoles followed by aza-Diels–Alder reaction of thus obtained 5-indolyl-1,2,4-triazines with 2,5-norbornadiene in a pressure vessel. The reactions sequence provides good yields and is suitable for wide scope of substituted 1,2,4-triazines.