A new palladium catalyzed synthesis of ,-2,3-diarylsubstituted bicyclo[2.2.1]heptanes or bicyclo [2.2.1] hept-2-enes
作者:Marta Catellani、Gian Paolo Chiusoli、Stefano Concari
DOI:10.1016/s0040-4020(01)81100-5
日期:1989.1
The title bicycloheptanes or bicycloheptenes, containing a phenyl group and an aryl group in 2,3 positions, are obtained by oxidative addition of aryl bromides to palladium(0), followed by double bond insertion and coupling with a phenyl group of tetraphenyl borate anion.
[GRAPHICS]In contrast to the Pd(0)-catalyzed mechanism by Uemura, Mizoroki-Heck type reaction of boronic acids is found to proceed under a Pd(ll)mediated pathway using a catalytic amount of Pd(OAc)(2) in the presence of Cu(OAc)(2) as an oxidant. Treatment of a variety of alkenes with boronic acids, boronates, and sodium tetraphenylborate furnishes beta -arylated and alkenylated products in good to excellent yields. The reactions with norbornene, norbornadiene, and diphenylacetylene are also performed to give 1:2 or 2:1 coupling products.
KOSUGI, MASANORI;TAMURA, HIROYUKI;SANO, HIROSHI;MIGITA, TOSHIHIKO, TETRAHEDRON, 45,(1989) N, C. 961-967
Norbornene and its derivatives are diarylated or dialkenylated by aryl- or alkenyltributylstannanes, a palladium catalyst, and chloroacetone or chloroacetonitrile as a reoxidant.