Palladium-Catalyzed [5 + 2] Heteroannulation of Phenethylamides with 1,3-Dienes to Dopaminergic 3-Benzazepines
作者:Álvaro Velasco-Rubio、Jesús A. Varela、Carlos Saá
DOI:10.1021/acs.orglett.0c01053
日期:2020.5.1
Phenethyltriflamides react with 1,3-dienes upon treatment with a catalytic amount of Pd(OAc)(2) and Cu(OAc)(2)/O-2 as oxidant to afford chemo-, regio- and diastereoselectively 2,3,4,5-tetrahydro-1H-benzo[d]azepines (3-benzazepine derivatives) in good to excellent yields. A DFT study of the [5 + 2] heteroannulation suggests a mechanistic pathway starting with formation of the six-membered palladacycle cis-PdX2L2 via a CMD process followed by eta(2) coordination and insertion of the 1,3-diene unit in a diastereoselective manner.