A divergent approach to benzylisoquinoline-type and oxoaporphine alkaloids via regioselective direct ring metalation of alkoxy isoquinolines.

Benedikt Melzer, Franz Bracher

Organic & biomolecular chemistry 2015 Jul 28

filter terms:

Methoxy- and benzyloxy-substituted isoquinolines are regioselectively metalated at C-1 with the Knochel-Hauser base, subsequent trapping with aromatic aldehydes gives aryl(isoquinolin-1-yl)carbinols as building blocks for divergent syntheses of different types of benzylisoquinoline alkaloids. Photochemical cyclization of ortho-bromo analogues under reductive conditions gives oxoaporphine alkaloids. Nine benzylisoquinoline alkaloids and two oxoaporphine alkaloids were obtained in two or three steps from appropriate isoquinolines.

Citation

Benedikt Melzer, Franz Bracher. A divergent approach to benzylisoquinoline-type and oxoaporphine alkaloids via regioselective direct ring metalation of alkoxy isoquinolines. Organic & biomolecular chemistry. 2015 Jul 28;13(28):7664-72