Rhodium(III)-Catalyzed Diastereoselective Ring-Opening of 7-Azabenzonorbornadienes with Aromatic Ketoximes: Synthesis of Benzophenanthridine Derivatives

J Org Chem. 2019 Dec 6;84(23):15590-15604. doi: 10.1021/acs.joc.9b02582. Epub 2019 Nov 25.

Abstract

A rhodium(III)-catalyzed redox-neutral ring-opening of 7-azabenzonorbornadienes with aromatic ketoximes giving 2-arylated hydronaphthylamines in a highly diastereoselective manner is described. Later, the 2-arylated hydronaphthylamines were converted into highly sensitive 13,14-dehydro benzophenanthridine derivatives by HCl hydrolysis. Further, 13,14-dehydro benzophenanthridines were aromatized into biologically important benzophenanthridine derivatives in the presence of DDQ. A possible reaction mechanism was proposed and supported by deuterium labeling studies and isolation of a rhodacycle intermediate.

Publication types

  • Research Support, Non-U.S. Gov't