Superacidic activation of quinoline and isoquinoline; their reactions with cyclohexane and benzene(1).
Quinoline (1) and isoquinoline (2), upon activation by strong acids, lead to intermediate N,C-diprotonated dications, which are involved in reactions with weak nucleophiles. Thus, 1 and 2 undergo selective ionic hydrogenation with cyclohexane in CF3SO3H-SbF5, HBr-AlBr3-CH2Br2, or HCl-AlCl3-CH2Cl2 acid systems to give their 5,6,7,8-tetrahydro derivatives. They also readily condense with benzene in the presence of HBr-AlBr3 or HCl-AlCl3 to provide 5,6,7,8-tetrahydro-5,7-diphenylquinoline (10) and 5,6,7,8-tetrahydro-6,8-diphenylisoquinoline (12), respectively.
Koltunov
Konstantin Yu
KY
Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, University Park, Los Angeles, CA 90089-1661, USA. koltunov@catalysis.ru
Prakash
G K Surya
GK
Rasul
Golam
G
Olah
George A
GA