A NOVEL TYPE OF ZIRCONIUM-CATALYZED OR ZIRCONIUM-PROMOTED CYCLIZATIONREACTION

Citation
T. Takahashi et al., A NOVEL TYPE OF ZIRCONIUM-CATALYZED OR ZIRCONIUM-PROMOTED CYCLIZATIONREACTION, Organometallics, 13(9), 1994, pp. 3411-3412
Citations number
27
Language
INGLESE
art.tipo
Note
Categorie Soggetti
Chemistry Inorganic & Nuclear","Chemistry Inorganic & Nuclear
Journal title
ISSN journal
0276-7333
Volume
13
Issue
9
Year of publication
1994
Pages
3411 - 3412
Database
ISI
SICI code
0276-7333(1994)13:9<3411:ANTOZO>2.0.ZU;2-T
Abstract
Intramolecular cyclization reactions of YCH2CH=CHCH(2)XCH(2)CH=CH2 (X = CH2, NPr, NPh; Y = PhO, MeO), which have a terminal double bond and an allylic ether moiety, were catalyzed by zirconocene dichloride (10- 20 mol %) in the presence of n-BuMgCl. Cyclization products 2-methyl-1 -vinylcyclopentane, 4-methyl-1-propyl-3-vinylpyrrolidine, and 4-methyl -1-phenyl-3-vinylpyrrolidine were obtained in 60-80% yields. Stoichiom etric cyclization with Cp(2)ZrBu(2) or (C(5)H(3)Me(2))(2)ZrBu(2) at ro om temperature gave the same products in high yields after hydrolysis. When an excess Of CP(2)ZrBu(2) was used, the stereoisomerization of c is product to trans isomer was observed.