Synthesis of cyclobutenes and allenes by cobalt-catalyzed cross-dimerization of simple alkenes with 1,3-enynes.
Cobalt-catalyzed cross-dimerization of simple alkenes with 1,3-enynes is reported. A [2+2] cycloaddition reaction occurred, with alkenes bearing no allylic hydrogen, by reductive elimination of a η(3)-butadienyl cobaltacycle. On the other hand, aliphatic alkenes underwent 1,4-hydroallylation by means of exo-cyclic β-H elimination. These reactions can provide cyclobutenes and allenes that were previously difficult to access, from simple substrates in a highly chemo- and regioselective manner.
Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan), Fax: (+81) 6-6879-7394.
Akira
A
Nishimura
Eri
E
Tamai
Masato
M
Ohashi
Sensuke
S
Ogoshi
1,3-enyenes; alkenes; allenes; cobalt; cyclobutene