Hydrogen bonding of hydroxy groups to carbanions in indenide- and fluorenide-derivatized alcohols directly observed by UV, IR, and NMR spectroscopy
作者:Ian Mc Ewen、Mats Roennqvist、Per Ahlberg
DOI:10.1021/ja00063a019
日期:1993.5
For investigation of hydrogen bonding to carbanions a number of carbanions containing hydroxy groups have been designed and synthesized. The carbanions were of the type R'-CR 2 -CHR-CR 2 -OH, with R'being an indenide or a fluorenide group and R a methyl group or a hydrogen, and were generated from the corraponding indenes and fluorenes. Intramolecular hydrogen bonding was observed by UV, IR, and NMR
Carbon acidity. 74. The effects of hetero-substituted pendant groups on carbanion reactivity. Solvent separated-contact ion pair equilibria and relative pKLi/THF's for 9-substituted fluorenyllithiums in tetrahydrofuran. The importance of internal chelation
作者:Scott. Gronert、Andrew. Streitwieser
DOI:10.1021/ja00217a024
日期:1988.4
Les substituants sont les groupes: methoxyethyl-, dimethylaminoethyl-, methylthioethyl-, butyl-, CH 3 OCH 2 CH 2 OCH 2 CH 2 -, H-
取代基:甲氧基乙基-、二甲氨基乙基-、甲硫基乙基-、丁基-、CH 3 OCH 2 CH 2 OCH 2 CH 2 -、H-
Catalysts
申请人:——
公开号:US20030225275A1
公开(公告)日:2003-12-04
The invention describes ligands of formula (I), wherein LIG represents an &eegr;
5
-ligand substituted by a group R
1
and a group (R″)
m
; X represents a 1 to 3 atom bridge; Y represents a nitrogen or phosphorus atom; Z represents a carbon, nitrogen or phosphorus atom.
ansa-Metallocenes with a Ph2Si bridge: molecular structures of HfCl2[Ph2Si(η5-C13H8)(η5-C5H4)] and HfCl2[Ph2Si(C13H9)(η5-C5H4)]2†
作者:Vyacheslav V. Izmer、Anton Y. Agarkov、Valentina M. Nosova、Lyudmila G. Kuz’mina、Judith A. K. Howard、Irina P. Beletskaya、Alexander Z. Voskoboynikov
DOI:10.1039/b009280k
日期:——
A mixture of rac- and meso-HfCl2[Ph2Si(η5-C9H6)2] was synthesized by treatment of HfCl4 with the dilithium salt of di(1H-inden-1-yl)diphenylsilane. These complexes were isolated after fractional crystallization in 15.5 and 8.5% yields, respectively. A sterically strained ansa complex HfCl2[Ph2Si(η5-C13H8)(η5-C5H4)] was synthesized in 62% yield by treatment of HfCl4 with the dilithium salt of cyclopentadienyl(fluoren-9-yl)diphenylsilane. Both this compound, and the by-product of reaction, HfCl2[Ph2Si(C13H9)(η5-C5H4)]2, were characterized by crystal structure analysis.
Lithium Complexes with Bridging and Terminal NHC Ligands: The Decisive Influence of an Anionic Tether
作者:Kieren J. Evans、Cameron L. Campbell、Mairi F. Haddow、Christian Luz、Paul A. Morton、Stephen M. Mansell
DOI:10.1002/ejic.201901003
日期:2019.12.15
a synergic mixture of LiPh/LiN(SiMe3)2 or LinBu/LiN(SiMe3)2 to give a dilithium complex incorporating a bridging N(SiMe3)2 ligand. In contrast, deprotonation of the imidazolium salt [9-(C13H9)C2H4N(CH)C2H2N(Me)][Br] instead yielded the free NHC, which reacted with nBuLi to form a dimeric, NHC-bridged dilithium complex. Addition of LiN(SiMe3)2 led to coordination and the formation