om201248t_si_001.pdf (204.07 kB)
Computational Study on the Palladium-Catalyzed Allenylative Dearomatization Reaction
journal contribution
posted on 2012-02-13, 00:00 authored by Ying Ren, Jianfeng Jia, Ting-Ting Zhang, Hai-Shun Wu, Wenxian LiuThe detailed mechanism of the Pd-catalyzed coupling of
naphthalene
allyl chloride with allenyltributylstannane, resulting in the dearomatization
of the naphthalene group, has been studied using density functional
theory (DFT) calculations at the B3LYP level. The catalyst cycle can
be divided into three main stages involving oxidative addition, transmetalation,
and reductive elimination, none of which contains significantly large
barriers. It is found that the oxidative addition takes place through
a monophosphine pathway. The transmetalation step is responsible for
the formation of the propargylic dearomatized product, due to the
orientation of the metal-coordinated allenyl ligand. Reductive elimination
of the dearomatized product from the intermediate (η3-allylnaphthalene)(η1-allenyl)PdPH3 occurs
by coupling of the terminal carbon of the η1-allenyl
ligand with the ortho carbon of the η3-naphthalene
ligand. Furthermore, it is shown that dichloromethane as solvent does
not change the mechanistic picture significantly.