Fe-catalyzed synthesis of substituted N-aryl oxazolidines.

A novel iron-catalyzed synthesis of substituted N-aryl oxazolidines was developed via C-N bond formation and methylenation. The reaction of aryl hydroxylamines with allyl alcohols, in the presence of formaldehyde or its equivalents, afforded variety of oxazolidine heterocycles in very good yields. This catalytic method is most effective for para-substituted aryl hydroxylamines and 3-methyl allyl alcohols. Furthermore, acid catalyzed demethylenation of oxazolidines allowed access to N-aryl amino alcohols in good yields.

Synthesis of substituted quinolines via allylic amination and intramolecular Heck-coupling.

A new catalytic approach for the synthesis of substituted quinolines via C-N and C-C bond formation using 2-haloaryl hydroxylamines and allylic C-H substrates is described. Fe-catalyzed allylic C-H amination followed by Pd-catalyzed intramolecular Heck-coupling and aerobic dehydrogenation deliver the valuable quinoline and naphthyridine heterocycles in good to excellent overall yields. In this process, Pd(OAc)2 plays a dual role in catalyzing Heck coupling as well as aerobic dehydrogenation of dihydroquinolines.