[4+2] cycloaddition of o-xylylenes with imines using palladium catalyst.
The cycloaddition of o-(silylmethyl)benzylic carbonates with imines proceeded in the presence of the Pd(eta(3)-C(3)H(5))Cp-DPPPent catalyst, affording the tetrahydroisoquinolines in good to high yields. The reaction rate was remarkably increased by a fluoride additive. In the catalytic cycloaddition, the palladium(0) reacted with the benzylic substrate to form 2-palladaindane, which works as an o-xylylene equivalent. The catalytic reaction is equivalent to the hetero-Diels-Alder reaction of o-xylylene with imines.
Ueno
Satoshi
S
Department of Chemistry, Graduate School of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
Ohtsubo
Masakazu
M
Kuwano
Ryoichi
R