15570-45-3Relevant articles and documents
Bandara et al.
, p. 2587 (1974)
Interactions in molecular crystals, 126 [1,2] the cation solvation in solvent-shared and solvent-separated ion multiples of 1,2,3,4-tetraphenylcyclopentadienyl-sodium salts
Bock, Hans,Hauck, Tim,N?ther, Christian,Havlas, Zdenek
, p. 524 - 534 (1997)
The 1,2,3,4-tetraphenyl-shielded sodium cyclopentadienide, Na⊕[HC5?(C6H5)4], demonstrates essential facets of structure-determining cation solvation. The following solvent-shared or solvent-separated ion multiples have been crystallized from the respective aprotic ether solutions and structurally characterized: [(C29H21?)Na⊕ (THF)7/2], [(C29H21?)Na⊕(DME)2], [(C29H21?)]?[Na⊕(diglyme) 2]⊕, [(C29H21?)]?[Na⊕(triglyme) 2]⊕ and, from 18-crown-6 solution, the novel tripeldecker ion triple, [(C29H21?)]? 2[Na⊕(18-crown-6)Na⊕(18-crown-6)Na⊕(18-crown-6)] ⊕⊕, which contains two Na⊕ counter cations between three 18-crown-6 discs. The structures, discussed in comparison with literature data and based on MNDO calculations, demonstrate the essential effects of Na⊕ counter cation solvation by various ether ligands.
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Michman,Zeiss
, p. 161,165 (1970)
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1,2,3,4-Tetrasubstituted cyclopentadienes and their applications for metallocenes: Efficient synthesis through zirconocene- and CuCl-mediated intermolecular coupling of two alkynes and one diiodomethane
Geng, Weizhi,Wang, Chao,Guang, Jie,Hao, Wei,Zhang, Wen-Xiong,Xi, Zhenfeng
, p. 8657 - 8664 (2013/07/26)
1,2,3,4-Tetrasubstituted cyclopentadienes and indene derivatives with identical or different substituents were obtained in good to excellent isolated yields through a zirconocene- and CuCl-mediated intermolecular coupling process. This synthetic procedure involved three organic partners, including one CH 2I2, and two different or identical alkynes. Two alkynes or one diyne undergo Cp2ZrII-mediated (Cp= η5-C5H5) pair-selective reductive coupling to afford the corresponding zirconacyclopentadiene derivatives, which react, in the presence of CuCl and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1 H)-pyrimidinone (DMPU), with CH2I2 through intermolecular followed by intramolecular coupling to afford the cyclopentadiene derivatives. An application of the prepared tetrasubstituted cyclopentadiene derivatives was demonstrated by the facile synthesis of the corresponding zirconocene complexes [(4RCp)2ZrCl2] and [(4RCp) 2ZrR′2] (R′=Me, Et, or nBu). The unique 1,2,3,4-tetrasubstituted cyclopentadiene ligands and the corresponding metallocenes are expected to have further applications in organometallic chemistry and organic synthesis. Ringing in the changes: A one-pot synthesis of 1,2,3,4-tetrasubstituted cyclopentadienes by zirconocene- and CuCl-mediated intermolecular coupling of two alkynes and diiodomethane (see scheme; Cp=η5-C5H5; DMPU=1,3-dimethyl-3,4,5,6- tetrahydro-2(1 H)-pyrimidinone) gave products that were successfully applied for the synthesis of the corresponding zirconocene derivatives. Copyright
Volume parameters of some Diels - Alder reactions involving C=C, C=S, and N=N bonds
Kiselev,Kashaeva,Potapova,Iskhakova,Konovalov
, p. 2034 - 2041 (2007/10/03)
The effect of a hydrostatic pressure of up to 1000 kg cm-2 on the rate constants of the Diels - Alder reactions of maleic anhydride with 1,2,3,4-tetraphenylcyclopentadiene and with 6,13-dichloropentacene, of 4-phenyl-1,2,4-triazoline-3,5-dione with hexachlorocyclopentadiene, and of thiobenzophenone with isoprene was studied at 25°C. The volume parameters and ratios of the activation to reaction volumes make it possible to exclude electrostriction of the solvent during transition state solvation in all the reactions studied, which corresponds to the nonpolar nature of the transition state.
