Synthesis of highly crowded cyclopentadienes via reactions of Cp2Ni and CpSn(CH3)3with triarylmethylhalogenides. Molecular structure of 1-(CH3)3Si(3-Ph3C)C5H4

Autor: Rufanov, Konstantin A., Kazennova, Nadezhda B., Churakov, Andrew V., Lemenovskii, Dmitry A., Kuz'mina, Ludmila G.
Zdroj: Journal of Organometallic Chemistry; January 1995, Vol. 485 Issue: 1-2 p173-178, 6p
Abstrakt: Triphenylmethylcyclopentadiene Ph3CC5H5(1) and 2-[tris-(2′-methoxyphenyl)methyl]cyclopentadiene 2-((2′-CH3OC6H4)3C)C5H5(2) have been prepared in high yields via reactions of the corresponding triarylmethyl-halogenides with Cp2Ni (and CpSn(CH3)3in the case of1). It is shown that 3-tritylsubstituted 6,6-dimethylfulvene formed exclusively in the reaction between the lithium salt of1and acetone. Cyclopentadiene2exists only as the 2-triarylmethylsubstituted isomer in a mixture of two enantiomeric forms caused by the C3v-asymmetry type in the relative orientation of the aryl groups. Cyclopentadiene 1-Si(CH3)3-(3-Ph3C)-C5H4was obtained by reaction of the sodium salt of1with (CH3)3SiCl; it crystallizes from hexane in the monoclinic space group P21/cwith cell dimensions a= 11.635(5), b= 12.400(7), c= 15.531(7)Å, V= 2240.09(9)Å3and Z= 4; the Si atom is in the allylic position with d(CCpSi) = 1.891(8)Å,SiC(3)C(2) = 109.7(6)°,SiC(3)C(4) = 110.3(6)°,C(2)C(3)C(4) = 100.2(7)°.
Databáze: Supplemental Index
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