Synthesis and biological evaluation of unnatural derivatives of narciclasine: 7-aza-nornarciclasine and its N-oxide

Several unnatural derivatives of narciclasine were prepared in which the C-7 carbon was replaced with nitrogen. The 7-aza derivative and its N-oxide were prepared by the coupling of iodopicolinic acid with a conduramine unit derived chemoenzymatically from bromobenzene. Intramolecular Heck reaction was used to construct the isocarbostyryl ring system. The compounds were submitted to biological screening against cancer cell lines. Full experimental and spectra data are provided for all new compounds. (C) 2014 Elsevier Ltd. All rights reserved.