M. Shimizu et al., OXIDATION OF 1,2,3,4-TETRAHYDROISOQUINOLINES TO 3,4-DIHYDROISOQUINOLINES WITH MOLECULAR-OXYGEN CATALYZED BY COPPER(II) CHLORIDE, Heterocycles, 41(4), 1995, pp. 773-779
A catalytic oxidation system, a CuCl2-O-2 system, was efficient for de
hydrogenation of 1,2,3,4-tetrahydroisoquinolines to 3,4-dihydroisoquin
olines. Oxidation of 1,2,3,4-tetrahydroquinoline was also carried out.