Return to search

Preparation of substituted cyclopentadienyl ligands by nucleophilic addition to substituted fulvenes

By modifing the procedure reported by Stone and Little, we have been able to make substituted fulvenes on a large scale and maintain good yield. Treatment of 6-tert-butylfulvene with lithium diethylamine gave, upon work-up, neopentylcyclopentadiene in 83% yield. Treatment of neopentylcyclopentadiene with n-butyllithium followed by zirconium tetrachloride gave [ƞ5-C5H4CH2C(CH3)3]2ZrCl2 in 19% yield. Treatment of 6-tert-butylfulvene with lithium 1,2,3,4-tetrahydroisoquinoline gave, upon work-up, neopentylcyclopentadiene in 71% yield- and a mixture of 3,4-dihydroisoquinoline, 1,4-dihydroisoquinoline and isoquinoline in 72% combined yield. Treatment of 6-methyl-6-phenylfulvene with dilithio-Ɩ-proline at -78 °C gave, upon work-up, a 99% yield of 1-cyclopentadienyl-1-phenylethane, 17.4% ee. Treatment of 6-methyl-6-phenylfulvene with dilithio (s)-(-)-2-pyrrolidone-5-carboxylic acid at -78 °C gave, upon work-up, a 99% yield of 1-cyclopentadienyl-1-phenylethane, 8.7% ee. Treatment of 1-cyclopentadieny-11-phenylethane (8.7% ee) with one equivalent of n-BuLi followed by treatment with lithium cyclopentadienide and ferrous chloride gave, upon work-up, [C5H5][C5H4(CH(CH3)C6H5)]Fe, 10.5% ee. Treatment of 1-cyclopentadienyl-1-phenylethane (17.4% ee) with one equivalent of n-BuLi followed by treatment with cyclopentadienyltitanium trichloride gave, upon work-up, a 48% yield of [C5H5][C5H4(CH(CH3)C6H5)]TiCl2. Treatment of 1-cyclopentadienyl-1-phenyl-ethane (17.4% ee) with one equivalent of n-BuLi followed by treatment with zirconium tetrachloride gave [C5H4(CH(CH3)C6H5)]2ZrCl2 in 78% yield. Treatment of 6-tert-butylfulvene with excess of cyclopentadienyl lithium gave, upon work-up, 1, 1-bis(cyclopentadienyl)-1-tert-butylmethane in 34% yield. Treatment of 1, 1-bis(cyclopentadienyl)-1-tert-butylmethane with two equivalent of methylmagnesium bromide or isopropylmagnesium chloride followed by quenching with D2O gave 1,1-bis(cyclopentadienyl)-l-tert-butylmethane-d2 in 56.9% and 84.1% yield respectively. Treatment of fluorenyl lithium with 6-tert-butylfulvene gave, upon work-up, a 44% yield of 1-cyclopentadienyl-1-fluorenyl-2,2-dimethylpropane as a yellow solid. Treatment of this yellow solid with two equivalent of n-BuLi followed by treatment with zirconium tetrachloride gave a 72% yield of neopentyl(cyclopentadienyl-l-fluorenyl) zirconium chloride.

Identiferoai:union.ndltd.org:auctr.edu/oai:digitalcommons.auctr.edu:dissertations-4005
Date01 August 1990
CreatorsShen, Lihong
PublisherDigitalCommons@Robert W. Woodruff Library, Atlanta University Center
Source SetsAtlanta University Center
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceETD Collection for AUC Robert W. Woodruff Library

Page generated in 0.0017 seconds