Ruthenium-Catalyzed Synthesis of Quinolines from Anilines and Tris(3-hydroxypropyl)amine via Amine Exchange Reaction

O, 3a was produced in only 5% yield (entry 2).Furthermore, the addition of a suitable hydrogen acceptorwas necessary for the effective formation of 3a. Performingthe reaction in the absence of hydrogen acceptor resulted in alower yield of 3a when compared to the reaction in thepresence of hydrogen acceptor (entries 1 and 3). Severalhydrogen acceptors such as acetophenone and dodec-1-enecould be alternatively used, but the yield of 3a was lowerthan that when acetone was used (entries 4 and 5). However,performing the reaction in the presence of oct-1-yne wasineffective and GLC analysis of crude reaction mixtureshowed very complicated products, which may be attributedto dimerization and trimerization of oct-1-yne under rutheniumcatalyst system (entry 6).