Palladium‐Catalyzed Synthesis of Alkylcarbazoles and Their Identification in Petroleum and Source Rocks**

Abstract

We describe the synthesis of seven C2‐alkylcarbazoles via a sequence of Buchwald–Hartwig coupling of arylamines with aryl halides followed by oxidative cyclization of the resulting diarylamines. Methyl groups at the positions 4 and 5 were introduced by taking advantage of the ortho‐directed palladation of meta‐pivaloyloxy‐substituted diarylamines and subsequent conversion of the pivaloyloxy to methyl groups through Stille coupling of intermediate triflates. The obtained ethyl‐ and dimethylcarbazoles served as analytical standards for their identification in petroleum samples and source rocks.