911023-00-2Relevant academic research and scientific papers
Sequential N-acylamide methylenation-enamide ring-closing metathesis: Construction of benzo-fused nitrogen heterocycles
Bennasar, M. Lluisa,Roca, Tomas,Monerris, Manuel,Garcia-Diaz, Davinia
, p. 7028 - 7034 (2007/10/03)
The dimethyltitanocene methylenation of N-acylamides derived from ortho-vinylanilines, ortho-allylaniline, and ortho-vinylbenzylamine provides the corresponding enamides, which upon exposure to the second generation Grubbs ruthenium catalyst give access to indoles, 1,4-dihydroquinolines, and 1,2-dihydroisoquinolines, respectively. This sequential protocol also allows the synthesis of dihydrobenzoazepines, although the ring-closing metathesis (RCM) step is complicated by the alkene isomerization processes. From certain substrates, the direct annulation is observed in the titanium-mediated step, which is likely to occur through an olefin metathesis-intramolecular olefination sequence.
