Koltunov Konstantin Yu, Prakash G K Surya, Rasul Golam, Olah George A
Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, University Park, Los Angeles 90089-1661, USA.
J Org Chem. 2002 Dec 13;67(25):8943-51. doi: 10.1021/jo0204855.
Isomeric 1- and 3-isoquinolinols (11 and 12) when activated in CF(3)SO(3)H-SbF(5) acid system undergo selective ionic hydrogenation with cyclohexane to give 5,6,7,8-tetrahydro-1(2H)- and 5,6,7,8-tetrahydro-3(2H)-isoquinolinones (22 and 27). Under the influence of aluminum chloride similar products were also obtained along with 3,4-dihydro-1(2H)- and 1,4-dihydro-3(2H)-isoquinolinones (23 and 28), respectively. Compounds 11 and 12 also condense with benzene in the presence of aluminum halides, under mild conditions, to give 3,4-dihydro-3-phenyl-1(2H)- and 1,4-dihydro-1-phenyl-3(2H)-isoquinolinones (24 and 29), respectively. Prolonged reaction time or catalysis under strongly acidic HBr-AlBr(3) provides an alternative reaction pathway to yield 5,6-dihydro-6,8-diphenyl-1(2H)- and 5,6,7,8-tetrahydro-6,8-diphenyl-3(2H)-isoquinolinones (25 and 30), respectively. Products 24 and 29 were also found to revert back to 11 and 12 in the presence of aluminum halides in o-dichlorobenzene. The mechanism of these intriguing reactions, which involves superelectrophilic dicationic intermediates, is discussed.
异构的1-和3-异喹啉醇（11和12）在CF(3)SO(3)H-SbF(5)酸体系中被活化时，与环己烷发生选择性离子氢化反应，生成5,6,7,8-四氢-1(2H)-和5,6,7,8-四氢-3(2H)-异喹啉酮（22和27）。在氯化铝的作用下，也得到了类似的产物，同时分别生成了3,4-二氢-1(2H)-和1,4-二氢-3(2H)-异喹啉酮（23和28）。化合物11和12在卤化铝存在下，在温和条件下也能与苯缩合，分别生成3,4-二氢-3-苯基-1(2H)-和1,4-二氢-1-苯基-3(2H)-异喹啉酮（24和29）。延长反应时间或在强酸性HBr-AlBr(3)条件下催化，提供了另一种反应途径，分别生成5,6-二氢-6,8-二苯基-1(2H)-和5,6,7,8-四氢-6,8-二苯基-3(2H)-异喹啉酮（25和30）。还发现产物24和29在邻二氯苯中卤化铝存在下会逆转为11和12。讨论了这些有趣反应的机理，该机理涉及超亲电双阳离子中间体。
