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

We describe the synthesis of seven C-2-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.

Automated summary

This study successfully synthesized seven C-2-alkylcarbazoles using a series of methods, providing analytical standards for identifying them in petroleum samples and source rocks.