Dehydrogenative Carbon-Carbon Bond Formation Using Alkynyloxy Moieties as Hydrogen-Accepting Directing Groups.
In the presence of a catalyst system consisting of Pd(OAc)2 , PCy3 , and Zn(OAc)2 , the reaction of alkynyl aryl ethers with bicycloalkenes, α,ß-unsaturated esters, or heteroarenes results in the site-selective cleavage of two C-H bonds followed by the formation of C-C bonds. In all cases, the alkynyloxy group acts as a directing group for the activation of an ortho C-H bond and as a hydrogen acceptor, thus rendering the use of additives such as an oxidant or base unnecessary.
Research and Development Initiative, Chuo University and JST, ACT-C, Kasuga, Bunkyo-ku, Tokyo 112-8551 (Japan). yminami@kc.chuo-u.ac.jp.
Yasunori
Y
Minami
Department of Applied Chemistry, Chuo University, Kasuga, Bunkyo-ku, Tokyo 112-8551 (Japan).
Tatsuro
T
Kodama
Research and Development Initiative, Chuo University and JST, ACT-C, Kasuga, Bunkyo-ku, Tokyo 112-8551 (Japan). thiyama@kc.chuo-u.ac.jp.
Tamejiro
T
Hiyama
CC coupling; CH activation; alkynes; annulation; palladium