872332-96-2

Upstream product

• 123-11-5 4-methoxy-benzaldehyde 
• 93-55-0 1-phenyl-propan-1-one 
• 66323-99-7 trimethyl[(Z)-(1-phenyl-1-propenyl)oxy]silane 
• 37471-46-8 1-phenyl-1-trimethylsiloxypropene 

Relevant academic research and scientific papers

Self-Assembled Single-Walled Metal-Helical Nanotube (M-HN): Creation of Efficient Supramolecular Catalysts for Asymmetric Reaction

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.

Asymmetric aldol reaction catalyzed by a chiral phosphine-silver complex

A catalytic asymmetric aldol reaction of alkenyl trihaloacetates or a γ,δ-unsaturated δ-lactone with aldehydes or an α-keto ester was achieved by using a 2,2′-bis(diphenylphosphino)-1,1′- binaphthyl·silver trifluoromethanesulfonate complex as the chiral p

Iron(II)-derived lewis acid/surfactant combined catalysis for the enantioselective mukaiyama aldol reaction in pure water

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,

Iron- and bismuth-catalyzed asymmetric mukaiyama aldol reactions in aqueous media

We have developed asymmetric Mukaiyama aldol reactions of silicon enolates with aldehydes catalyzed by chiral FeII and BiIII complexes. Although previous reactions often required relatively harsh conditions, such as strictly anhydrous conditions, very low temperatures (-78 °C), etc., the reactions reported herein proceeded in the presence of water at 0 °C. To find appropriate chiral water-compatible Lewis acids for the Mukaiyama aldol reaction, many Lewis acids were screened in combination with chiral bipyridine L1, which had previously been found to be a suitable chiral ligand in aqueous media. Three types of chiral catalysts that consisted of a FeII or BiIII metal salt, a chiral ligand (L1), and an additive have been discovered and a wide variety of substrates (silicon enolates and aldehydes) reacted to afford the desired aldol products in high yields with high diastereo- and enantioselectivities through an appropriate selection of one of the three catalytic systems. Mechanistic studies elucidated the coordination environments around the FeII and BiIII centers and the effect of additives on the chiral catalysis. Notably, both Bronsted acids and bases worked as efficient additives in the Fe II-catalyzed reactions. The assumed catalytic cycle and transition states indicated important roles of water in these efficient asymmetric Mukaiyama aldol reactions in aqueous media with the broadly applicable and versatile catalytic systems. Copyright

Iron(II) and zinc(II) complexes with designed pybox ligand for asymmetric aqueous Mukaiyama-aldol reactions

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

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

Asymmetric mukaiyama-aldol reaction in aqueous media promoted by zinc-based chiral lewis acids

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

Aqueous asymmetric Mukaiyama aldol reaction catalyzed by chiral gallium Lewis acid with trost-type semi-crown ligands

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).

Lanthanide Trifluoromethanesulfonate-catalyzed asymmetric aldol reactions in aqueous media

equation presented Catalytic asymmetric aldol reactions catalyzed by lanthanide trifluoromethanesulfonates in aqueous media have been realized for the first time using a chiral crown ether.

SYNTHETIC CONTROL LEADING TO CHIRAL COMPOUNDS

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