The directed ortho metalation reaction. Methodology, applications, synthetic links, and a non-aromatic ramification

Abstract

Three themes in context of Directed ortho Metalation (DoM) chemistry are developed: the use of the OSEM directed metalation group to achieve regiospecific synthesis of substituted benzene, naphthalene, and pyridine derivatives (Schemes 2-5); a tandem one-pot DoM - metal halogen exchange route to prepare diverse anthraquinones (Scheme 7) including antitumor ellipticine alkaloids (Scheme 8); a DoM - cross coupling link to attain m-terphenyl and biaryl amides which lead, by remote metalation, to condensed (Schemes 10, 11), simple (Scheme 12), and naturally occurring (Scheme 13) fluorenones. A diversion to a-metalated enol carbamates (Scheme 15) which provide new avenues to a myriad of acyl anion synthons (Schemes 16–20) is also described. © 1990, IUPAC.