71908-03-7Relevant academic research and scientific papers
Iron-Modified Mesoporous Silica as an Efficient Solid Lewis Acid Catalyst for the Mukaiyama Aldol Reaction
Xu, Wan,Ollevier, Thierry,Kleitz, Freddy
, p. 1932 - 1944 (2018/03/13)
Fe-MCM-41 and Fe-SBA-15, two different iron-containing mesoporous silicas, were successfully synthesized by a straightforward and versatile method using iron acetylacetonate as a metal precursor. pH adjustment with ammonia during the synthesis was found t
Synthesis of a Bolm's 2,2′-Bipyridine Ligand Analogue and Its Applications
Bedná?ová, Eva,Dra?ínsky, Martin,Malatinec, ?tefan,Císa?ová, Ivana,Lamaty, Frédéric,Kotora, Martin
supporting information, p. 2869 - 2878 (2018/08/17)
A new method of synthesis of an analogue of Bolm's 2,2′-bipyridine ligand based on the catalytic [2+2+2] cyclotrimerization of 1-halodiynes with nitriles was developed. Crucial step of the whole synthesis turned out to be homodimerization of a substituted 2-bromopyridine to the corresponding bipyridine, that was studied and optimized. The newly prepared bipyridine (S,S)-2 was then tested as a chiral ligand in metal-catalyzed enantioselective reactions. Out of the studied reactions the most promising results were obtained in epoxide ring opening (82% yield, 98% ee) and Mukaiyama aldol reaction (>96% yield, 99/1 dr, 92% ee). In the case of Mukaiyama-aldol reaction as well as in the Michael addition, novel ligand 2 proved its robustness compared to Bolm's ligand as it was less sensitive to the purity of used reagents. (Figure presented.).
Self-Assembled Single-Walled Metal-Helical Nanotube (M-HN): Creation of Efficient Supramolecular Catalysts for Asymmetric Reaction
Jiang, Jian,Meng, Yan,Zhang, Li,Liu, Minghua
supporting information, p. 15629 - 15635 (2016/12/16)
Ever since the axial chiral catalysts were developed for asymmetric reactions with excellent chiral discrimination and high efficiencies, the interest in the supramolecular catalyst has also been extensively investigated. Here, with a hint from the typical molecular catalyst, we developed a series of metal-coordinated nanotube (M-helical nanotube, M-HN) catalysts for asymmetric reactions. The M-HN catalyst was fabricated on the basis of the self-assembly of an l-glutamic acid terminated bolaamphiphile, which formed a single-walled nanotube. On one hand, through the coordination of transition metal ions with the carboxylic acid groups on the nanotube surface, a wide variety of single-walled M-HN catalysts could be fabricated, in which the coordination sites could serve as the catalytic sites. On the other hand, using a slight amount of these catalysts, significant reactivity and enantioselectivity were realized for certain asymmetric reactions under mild conditions. Remarkably, Bi(III)-HN could catalyze the asymmetric Mukaiyama aldol reaction with high enantioselectivity (up to 97% ee) in an aqueous system; Cu(II)-HN catalyzed the asymmetric Diels-Alder reaction with up to 91% ee within 60 min. It was suggested that a synergetic effect of the aligned multicatalytic sites and stereochemical selectivity of the M-HN lead to an excellent catalytic performance. Through this work, we proposed a new concept of a single-walled nanotube as catalyst and showed the first example of nanotube catalysts presenting high reactivity and enantioselectivity that rivaled a chiral molecular catalyst.
Synthesis, spectroscopic characterization, and reactivity of water-tolerant Eu3+-based precatalysts
Averill, Derek J.,Allen, Matthew J.
supporting information, p. 6257 - 6263 (2014/07/07)
We report the synthesis, spectroscopic characterization, and reactivity of Eu3+ in the presence of a new set of chiral ligands designed for the aqueous, enantioselective Mukaiyama aldol reaction. Luminescence and NMR measurements were used to characterize the coordination environments of the Eu3+-based precatalysts, and this data is compared with yields and stereoselectivities. In addition to structure-function relationships, we found that, in the presence of excess hexadentate ligands, Eu3+ is coordinatively saturated, and subsequently, the reactivity of the precatalysts is reduced. These findings are helpful for the design of new ligands that bind Eu3+ without saturating the Eu3+ coordination sphere.
Tetranuclear hafnium(IV) and zirconium(IV) cationic complexes sandwiched between Two Di-Lacunary species of α-keggin polyoxometalates: Lewis acid catalysis of the mukaiyamaaldol reaction
Nomiya, Kenji,Ohta, Kazuaki,Sakai, Yoshitaka,Hosoya, Taka-Aki,Ohtake, Atsushi,Takakura, Akira,Matsunaga, Satoshi
, p. 800 - 812 (2013/08/15)
The syntheses, X-ray structures, and homogeneous Lewis acid catalytic activities for the Mukaiyamaaldol reaction of four tetranuclear HfIV and ZrIV cluster cations, which are sandwiched between two 1,2-di-lacunary α-Keggin polyoxomet
Gallium(III) triflate catalyzed diastereoselective mukaiyama aldol reaction by using low catalyst loadings
Plancq, Baptiste,Justafort, Lyse Carole,Lafantaisie, Mathieu,Ollevier, Thierry
, p. 6525 - 6529 (2013/11/06)
A mild method for the diastereoselective Mukaiyama aldol reaction is reported. By using a low loading of the gallium(III) triflate catalyst (down to 0.01 mol-%), the transformation proceeds efficiently to afford the corresponding β-hydroxy ketones in yields up to 92a€‰%. To the best of our knowledge, this is the first report of a metal triflate acting as a safe, bench-stable, and slow-releasing source of triflic acid for the Mukaiyama aldol reaction. A diastereoselective Mukaiyama aldol reaction was performed under mild conditions with a low loading of the gallium(III) triflate catalyst (down to 0.01 mol-%). The transformation proceeded efficiently to afford the corresponding β-hydroxy ketones in yields up to 92a€‰%. Copyright
Synthesis of β-hydroxy and β-amino ketones from allylic alcohols catalyzed by ru(η5-C5Ph5)(CO)2Cl
Bartoszewicz, Agnieszka,Jezowska, Martina M.,Laymand, Kevin,Moebus, Juri,Martin-Matute, Belen
experimental part, p. 1517 - 1530 (2012/06/15)
An efficient method for the synthesis of β-hydroxy and β-amino ketones from allylic alcohols catalyzed by Ru(η5-C 5Ph5)(CO)2Cl is described. The influence of the stereoelectronic properties of the catalyst on the reaction outcome has been studied. Optimization of the reaction conditions supressed the formation of undesired side products such as saturated ketones, benzyl alcohols, and α,β-unsaturated ketones. Several aromatic and aliphatic allylic alcohols have been reacted with a large variety of aldehydes or imines to produce β-hydroxy ketones or β-amino ketones, respectively, in yields up to 99a%. Based on experimental data, a mechanism via ruthenium alkoxides and ruthenium aldoxides is proposed. In addition, a C-bound ruthenium enolate has been characterized. β-Hydroxy and β-amino ketones are synthesized from allylic alcohols and aldehydes or imines, respectively. The coupling reaction is catalyzed by Ru(η5-C5Ph5)(CO) 2Cl. Mechanistic investigations support a mechanism via ruthenium alkoxide intermediates.
Visible-light-induced photoreductive generation of radicals from epoxides and aziridines
Larraufie, Marie-Helene,Pellet, Remy,Fensterbank, Louis,Goddard, Jean-Philippe,Lacote, Emmanuel,Malacria, Max,Ollivier, Cyril
, p. 4463 - 4466 (2011/06/22)
It's a trap! Both epoxides and aziridines substituted by an aryl ketone can be reduced efficiently using visible-light photoredox catalysts. The radicals generated were trapped by allyl sulfones, and formed α-branched β-hydroxy or amino derivatives with high diastereocontrol (see scheme; dtbbpy=4,4′-di-tert-butyl-2,2′-bipyridine, ppy=2-phenylpyridine). Copyright
Titanium tetraiodide-promoted reductive enolate formation of α-tosyloxy ketone derivatives and aldol reaction with aldehydes
Hachiya, Iwao,Inagaki, Takao,Ishihara, Yasuhisa,Shimizu, Makoto
experimental part, p. 419 - 421 (2011/05/16)
Titanium tetraiodide-promoted reductive enolate formation from α-tosyloxy ketone derivatives and subsequent aldol reaction of the resulting enolates with aldehydes gave β-hydroxy ketones.
A new class of ligands for aqueous, lanthanide-catalyzed, enantioselective Mukaiyama aldol reactions
Mei, Yujiang,Dissanayake, Prabani,Allen, Matthew J.
supporting information; experimental part, p. 12871 - 12873 (2010/11/16)
The development of aqueous methods for generating enantiopure β-hydroxy carbonyl compounds is an important goal because these subunits compose many bioactive compounds and the ability to synthesize these groups in water has environmental and cost benefits. In this communication, we report a new class of ligands for aqueous, lanthanide-catalyzed, asymmetric Mukaiyama aldol reactions for the synthesis of chiral β-hydroxy ketones. Furthermore, we have used luminescence-decay measurements to unveil mechanistic information regarding the catalytic reaction via changes in water-coordination number. The precatalysts presented here yielded β-hydroxy carbonyls from aliphatic and aryl substrates with outstanding syn:anti ratios and enantiometric excesses of up to 49:1 and 97%, respectively.
