Synthesis of ring-substituted bis-η5-cyclopentadienyl derivatives of the Group IV elements containing the bicyclic ligands η5-C5H3(1,2-CH2–)n, n=4, 5, or 6
作者:Eleonora Polo、Ronan M Bellabarba、Giansiro Prini、Orazio Traverso、Malcolm L.H Green
DOI:10.1016/s0022-328x(98)01042-0
日期:1999.4
The synthesis of unsubstituted and substituted bicyclic η5-cyclopentadienyl ligands and their Group IV metal complexes [Mη5-C5H3(1,2-CH2–)n}2Cl2], where n=4, 5, 6 and M=Ti, Zr, Hf, is reported. An example of an ansa-bridged zirconium analogue is also described.
Crosslink-cyclized cyclopentadiene and dihalobis type metal compound containing same as ligand
申请人:——
公开号:US20010012902A1
公开(公告)日:2001-08-09
A process for producing a crosslink-cyclized cyclopentadiene, comprising the steps of reacting a cyclopentenone with an alkali metal hydride to thereby reduce the cyclopentenone (reduction step A) into a cyclopentenol; and reacting the cyclopentenol with a dehydrating agent to thereby dehydrate the cyclopentenol (dehydration step B) into a crosslink-cyclized cyclopentadiene of the general formula (III):
1
wherein each of R
1
and R
2
independently represents a hydrogen atom or a linear or branched saturated alkyl group having 1 to 6 carbon atoms, n is an integer of 3 to 10, and the broken line in the 5-membered ring denotes that the 5-membered ring has two double bonds.
Effective Catalytic Activity of the Hydrated Gold Catalyst NaAuCl4×2H2O To Construct Highly Fused Cyclopentenones
作者:Chang Oh、Swastik Karmakar、Ahyun Kim
DOI:10.1055/s-0028-1083288
日期:2009.1
synthesis of various carbocycle-fused highly substituted cyclopentenones is described to occur viatandem 1,2-shift of pivaloate followed by carbocyclization under the catalysis of the hydrated gold catalyst NaAuCl4˙2H2O. cyclopentenones - carbocycles - goldcatalysis - 1,2-pivaloate shift - Nazarov-type cyclization
Process for the preparation of condensed cyclopentadiene derivatives, 1, 3 disubstituted derivatives and metallocene type compounds containing them as ligand
申请人:HONSHU CHEMICAL INDUSTRY CO. LTD.
公开号:EP1122229A1
公开(公告)日:2001-08-08
A process for producing a crosslink-cyclized cyclopentadiene, comprising the steps of reacting a cyclopentenone with an alkali metal hydride to thereby reduce the cyclopentenone (reduction step A) into a cyclopentenol; and reacting the cyclopentenol with a dehydrating agent to thereby dehydrate the cyclopentenol (dehydration step B) into a crosslink-cyclized cyclopentadiene of the general formula (III):
wherein each of R1 and R2 independently represents a hydrogen atom or a linear or branched saturated alkyl group having 1 to 6 carbon atoms, n is an integer of 3 to 10, and the broken line in the 5-membered ring denotes that the 5-membered ring has two double bonds.
An efficient synthesis of 2-cyclopentenones from γ-ketoaldehyde acetals using lithium trimethylsilyldiazomethane. Its application to the synthesis of trichodenone C
作者:Atsushi Sakai、Toyohiko Aoyama、Takayuki Shioiri
DOI:10.1016/s0040-4039(00)01162-x
日期:2000.8
The reaction of gamma-ketoaldehyde acetals with lithium trimethylsilyldiazomethane afforded 2-cyclopentenones via the 1,5-C-H insertion of alkylidene carbene in high to moderate yields. Using this method, the synthesis of trichodenone C was achieved. (C) 2000 Elsevier Science Ltd. All rights reserved.