107-79-9Relevant articles and documents
Diastereoselective synthesis, structure and reactivity studies of ferrocenyloxazoline gold(i) and gold(II) complexes
Holz, Julia,Ayerbe García, Marta,Frey, Wolfgang,Krupp, Felix,Peters, René
, p. 3880 - 3905 (2018)
In the last few decades, gold complexes have demonstrated huge potential for soft Lewis acid catalysis. Despite the intensive research on Au complexes and planar chiral metallacycles, enantiopure ferrocenylgold complexes have-surprisingly-not been reported until the studies presented in this article. Herein, we report the asymmetric synthesis of planar chiral ferrocenyl Au(i) complexes. These dinuclear species form helically chiral ten-membered (NCCCAu)2 rings stabilized by aurophilic interactions. In supramolecular solid state structures, linear, zigzag or helical Au(i) wires with regular Au?Au separations were observed. The dissolved dinuclear entities could be oxidized by Au(i) to unique ferrocenyl Au(ii) complexes featuring short Au(ii)-Au(ii) bonds, while the ferrocene core remained intact. However, our initial studies revealed the issue of configurational lability of the ferrocenyl Au(ii) complexes in terms of the element of planar chirality in the presence of the gold source, (Me2S)AuCl. This was successfully addressed by a systematic study implementing permanent σ-donor ortho-protecting groups such as methyl and trimethylsilyl, which impede an epimerization event. Oxidation of the dinuclear Au(i) complexes was also accomplished by oxidative addition reactions with halogenated solvents, preferably CHCl3. Additional reactivity studies revealed that dinuclear Au(ii) dihalide complexes are also formed with reactive alkylhalides such as iodomethane, benzylbromide and benzyliodide. Interestingly, the whole spectral range of colors (violet, blue, green, yellow, and red) is covered by the title complexes depending on the Au oxidation state and the anionic ligands in the Au(ii) complexes. This appears to be quite unusual for ferrocenes, which typically adopt orange to red colors in a non-oxidized state.
Synthesis of Ferrocene Oxazoline N,O ligands and Their Application in Asymmetric Ethyl- and Phenylzinc Additions to Aldehydes
Nottingham, Chris,Benson, Robert,Müller-Bunz, Helge,Guiry, Patrick J.
, p. 10163 - 10176 (2015/11/03)
The synthesis of a range of novel gem-disubstituted ferrocene-oxazoline ligands and their application in both the asymmetric ethyl- and phenylzinc additions to aldehydes is reported. These studies reveal that gem-disubstitution of i-Pr-containing ferrocene oxazoline ligands results in increased enantioselectivity compared to their unsubstituted counterparts. Utilizing zinc catalysis, these ligands provided a wide range of secondary alcohols in yields of up to 93% with ee's of up to >99%. An interesting crystal structure of a ferrocene oxide-lithium tetramer showing lithium-nitrogen coordination in the solid state is also presented.
Method of Producing Diethylene-Glycol Tert-Butyl Ether Using Isobutylene and Diethylene Glycol
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Page/Page column 2-3; sheet 2, (2011/07/08)
Usually an analysis of fuel displacement accident is required before operating a reactor. In the present invention, fuel displacement accident is analyzed by linearly combining calculation results of single displacement layouts and a calculation result of a default placement layout. In this way, a number of displacement combinations to be analyzed can be reduced. And, thus, time for the analysis is saved and safety of the reactor core can be affirmed.
