519054-25-2Relevant academic research and scientific papers
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.
Iron(II)-derived lewis acid/surfactant combined catalysis for the enantioselective mukaiyama aldol reaction in pure water
Lafantaisie, Mathieu,Mirabaud, Anais,Plancq, Baptiste,Ollevier, Thierry
, p. 2244 - 2247 (2014/08/18)
The catalytic asymmetric Mukaiyama aldol reaction in pure water was performed by using a combination of iron(II) dodecyl sulfate, a chiral bipyridine ligand, and benzoic acid. By using the obtained iron(II)-derived Lewis acid/surfactant combined catalyst,
Study of the lanthanide-catalyzed, aqueous, asymmetric Mukaiyama aldol reaction
Mei, Yujiang,Averill, Derek J.,Allen, Matthew J.
scheme or table, p. 5624 - 5632 (2012/09/05)
The development of efficient methods for the asymmetric Mukaiyama aldol reaction in aqueous solution has received great attention. We have developed a new series of chiral lanthanide-containing complexes that produce Mukaiyama aldol products with outstanding enantioselectivities. In this paper, we describe an optimized ligand synthesis, trends in stereoselectivity that result from changing lanthanide ions, and an exploration of substrate scope that includes aromatic and aliphatic aldehydes and silyl enol ethers derived from aromatic and aliphatic ketones.
Iron(II) and zinc(II) complexes with designed pybox ligand for asymmetric aqueous Mukaiyama-aldol reactions
Jankowska, Joanna,Paradowska, Joanna,Rakiel, Bartosz,Mlynarski, Jacek
, p. 2228 - 2231 (2007/10/03)
An iron(II) complex with a hindered hydroxyethyl-pybox (he-pybox) ligand shows improved catalytic activity and enantioselectivity for asymmetric Mukaiyama-aldol reactions in aqueous media. This water-stable chiral Lewis acid promotes condensation of aroma
Zn(pybox)-complex-catalyzed asymmetric aqueous Mukaiyama-Aldol reactions
Jankowska, Joanna,Mlynarski, Jacek
, p. 1317 - 1321 (2007/10/03)
Catalytic asymmetric aldol reactions in aqueous media have been developed using chiral zinc complex. The aldol products have been obtained in high yields, high diastereocontrol, and good level of enantioselectivity. Various aromatic and α,β-unsaturated al
Aqueous asymmetric Mukaiyama aldol reaction catalyzed by chiral gallium Lewis acid with trost-type semi-crown ligands
Li, Hui-Jing,Tian, Hong-Yu,Wu, Yan-Chao,Chen, Yong-Jun,Liu, Li,Wang, Dong,Li, Chao-Jun
, p. 1247 - 1256 (2007/10/03)
The combination of Ga(OTf)3 with chiral semi-crown ligands (1a-e) generates highly effective chiral gallium Lewis acid catalysts for aqueous asymmetric aldol reactions of aromatic silyl enol ethers with aldehydes. A ligand-acceleration effect was observed. Water is essential for obtaining high diastereoselectivity and enantioselectivity. The p-phenyl substituent in aromatic silyl enol. ether (2 h) plays an important role and increases the enantioselectivity up to 95% ee. Although aliphatic silyl enol ethers provided low enantioselectivities and silylketene acetal is easily hydrolyzed in aqueous alcohol, the aldol reactions of silylketene thioacetal (12) with aldehydes in the presence of gallium-Lewis acid catalysts give the β-hydroxy thioester with reasonable yields and high diastereo- (up to 99:1) and enantioselectivities (up to 96% ee).
Asymmetric mukaiyama-aldol reaction in aqueous media promoted by zinc-based chiral lewis acids
Mlynarski, Jacek,Jankowska, Joanna
, p. 521 - 525 (2007/10/03)
Asymmetric aldol reactions in aqueous media have been realized by using zinc-based chiral Lewis acids. The aldol products have been obtained with high yield, diastereocontrol and a good level of enantioselectivity. The reactivity of both acetophenone and
Novel chiral gallium Lewis acid catalysts with semi-crown ligands for aqueous asymmetric Mukaiyama aldol reactions
Li, Hui-Jing,Tian, Hong-Yu,Chen, Yong-Jun,Wang, Dong,Li, Chao-Jun
, p. 2994 - 2995 (2007/10/03)
Asymmetric Mukaiyama aldol reactions in aqueous media (water-ethanol = 9:1) were catalyzed by chiral gallium catalysts with semi-crown ligands to give aldol products with good yields, syn-diastereoselectivities and enantioselectivities.
SYNTHETIC CONTROL LEADING TO CHIRAL COMPOUNDS
Mukaiyama, Teruaki,Iwasawa, Nobuharu,Stevens, Rodney W.,Haga, Toru
, p. 1381 - 1390 (2007/10/02)
A highly diastereoselective cross aldol reaction is developed using divalent tin enolates formed from stannous trifluoromethanesulfonate and carbonyl compounds.The reaction is extended to a highly enantioselective cross aldol reaction employing chiral dia
