Intramolecular redox reactions, scandium

Intramolecular Redox Reaction. Polycyclic tetrahydro-quinolines were prepared by a scandium triflate-catalyzed 1,5-hydride shift/ring-closure sequence (eq 27). While thetitlecom-pound readily catalyzes this intramolecular neutral C-H bond functionalization, Gd(OTf)3 proved to be more efficient. 

Scandium triflate catalyzed the intramolecular redox reaction from yne-enones to ring-fused tetrahydroquinolines (eq 28). This Lewis acid-catalyzed intramolecular redox domino reaction occurs via domino 1,5-hydride shift and cycUzation to afford tetrahydroquinolines in moderate to excellent yields and with high diastereoselectivity. A similar Sc(OTf)3-catalyzed tandem 1,5-hydride transfer cyclization process was applied in the construction of 3-amino-3-carboxy-tetrahydroquinoline derivatives (eq 29). ... 

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