192565-58-5

Upstream product

• 3230-45-3 (E)-N-benzylidene-2-hydroxyaniline 
• 31469-15-5 1-methoxy-2-methyl-1-trimethylsiloxy-1-propene 
• 1624-53-9 2-(benzylideneamino)phenol 

Relevant academic research and scientific papers

Active site design in a chemzyme: Development of a highly asymmetric and remarkably temperature-independent catalyst for the imino aldol reaction

Unusually robust: A remarkably temperature-independent catalyst has been developed for the imino aldol reaction of imines derived from ortho-aminophenols (see scheme). This catalyst is prepared from two equivalents of the VAPOL ligand and a zirconium tetraalkoxide. From a consideration of likely intermediates in the catalytic cycle it was deduced that a methyl substituent ortho to the phenol (R1) should enhance induction. This resulted in asymmetric inductions in excess of 98% ee at room temperature as well as at 100°C. TMS=trimethylsilyl.

Efficient catalytic enantioselective Mannich-type reactions using a zirconium-bis(binaphthol)methane complex

In the presence of a catalytic amount of a zirconium- bis(binaphthol)methane complex (5), Mannich-type reactions of aldimines with silyl enolates proceeded smoothly to afford the corresponding adducts in high yields with high enantiomeric excesses. (R)-(R

Enantioselective Mannich-type reaction catalyzed by a chiral Bronsted acid

No metal required: The Mannich-type reaction of ketene silyl acetals 2 with aldimines 1 proceeded highly enantioselectively to afford the syn isomer of β-aminoesters 3 with up to 96% ee under the influence of a chiral Bronsted acid 4 derived from (R)-BINO

Enantioselective mannich-type reactions using a novel chiral zirconium catalyst for the synthesis of optically active β-amino acid derivatives

Catalytic enantioselective Mannich-type reactions of silyl enol ethers with aldimines have been successfully performed using a novel chiral zirconium catalyst prepared from zirconium(IV) tert-butoxide (Zr(OrBu)4), 2 equiv of (R)-6,6'-dibromo-1,

Catalytic Asymmetric Mannich-Type Reactions Using a Novel Chiral Iron Complex

Catalytic asymmetric Mannich-type reactions using a novel chiral iron complex have been developed. The reactions proceeded smoothly in the presence of a catalyst prepared from iron(II) chloride, a BINOL derivative, and i-Pr2NEt. The desired pro

Preparation of β-amino esters by a chiral Bronsted acid catalyzed Mannich-type reaction

Mannich-type reactions of ketene silyl acetals with aldimines proceeded smoothly under the influence of 10 mol% of a cyclic chiral phosphate derivative derived from (R)-BINOL as a chiral Bronsted acid catalyst to furnish β-amino esters with excellent enan

An aromatic ion platform for enantioselective Br?nsted acid catalysis

Chiral acid catalysts are useful for the synthesis of enantioenriched small molecules, but the standard catalysts require laborious and expensive preparations. Here, we describe a chiral Br?nsted acid prepared in one step from naturally occurring (-)-menthol and readily available 1,2,3,4,5-pentacarbomethoxycyclopentadiene. Aromatic stabilization serves as a key contributing factor to the potent acidity of the resulting compound, which is shown to catalyze both Mukaiyama-Mannich and oxocarbenium aldol reactions with high efficiency and enantioselectivity. Catalyst loadings as low as 0.01 mole percent and preparative scalability (25 grams) are demonstrated. Alternative amide catalysts are also shown to be promising platforms. In addition to proton catalysis, a chiral anion pathway is demonstrated to be viable with this catalyst system.

A Powerful Chiral Phosphoric Acid Catalyst for Enantioselective Mukaiyama–Mannich Reactions

A new BINOL-derived chiral phosphoric acid bearing 2,4,6-trimethyl-3,5-dinitrophenyl substituents at the 3,3′-positions was developed. The utility of this chiral phosphoric acid is demonstrated by a highly enantioselective (ee up to >99 %) and diastereoselective (syn/anti up to >99:1) asymmetric Mukaiyama–Mannich reaction of imines with a wide range of ketene silyl acetals. Moreover, this method was successfully applied to the construction of vicinal tertiary and quaternary stereogenic centers with excellent diastereo- and enantioselectivity. Significantly, BINOL-derived N-triflyl phosphoramide constitutes a complementary catalyst system that allows the title reaction to be applied to more challenging imines without an N-(2-hydroxyphenyl) moiety.

Stereoselective synthesis and characterization of new enantiomerically pure phosphoric acids

Starting from (R)-6,6′-dimethyldiphenyl-2,2′-dicarboxylic acid, a novel class of enantiomerically pure cyclic dialkyl phosphates was synthesized and properly characterized. The absolute configuration was determined by 2D NOESY experiments. The catalytic behavior of the new chiral Bronsted acids was investigated in the stereoselective addition of a silyl keteneacetal to aldimines. The Mannich-type reaction was promoted in up to 94% yields and enantioselectivities up to 55%. On the basis of preliminary molecular mechanic calculations, a model of stereoselection was also proposed to explain the sense of the enantioselectivity observed in the reaction.

Enantioselective Mannich-type reaction catalyzed by a chiral phosphoric acid bearing an (S)-biphenol backbone

A novel chiral phosphoric acid bearing a biphenol backbone was synthesized and its catalytic activity was investigated in the enantioselective Mannich-type reaction of ketene silyl acetals with aldimines. Georg Thieme Verlag Stuttgart.