61841-05-2

Upstream product

• 23426-63-3 2-bromo-2-methylpropionic acid methyl ester 
• 98-86-2 acetophenone 
• 31469-15-5 1-methoxy-2-methyl-1-trimethylsiloxy-1-propene 
• 4316-35-2 acetophenone dimethyl acetal 
• 92233-97-1 methyl 2,2-dimethyl-3-phenyl-3-(trimethylsilyloxy)butanoate 

Relevant academic research and scientific papers

Bidentate Organoaluminum Lewis Acid for Selective Activation of Carbonyl over Acetal Functionality: Chemoselective Functionalization

Chemoselective functionalization of carbonyl compounds over acetals has been achieved by bidentate organoaluminum Lewis acid based on the selective double electrophilic activation of carbonyls.

Mukaiyama aldol reactions catalyzed by a trimeric organo aluminum(III) alkoxide

Mukaiyama aldol reactions of enol ethers with a variety of aldehydes and ketones are efficiently catalyzed at 0-25 °C by the sterically bulky trimeric organo aluminum(III) alkoxide 1 synthesized via the reaction of 3 equiv of AlMe3 with tripodal tris(2-hydroxy-3-tert-butyl-5-methylphenyl) methane and the elimination of 3 equiv of methane. Comparisons of its catalytic properties with the less sterically hindered analogue 2, the more sterically hindered analogue 3, a monomeric aluminum near-analogue 4, and a dimeric alumatrane 5 revealed that 1 possesses superior activity.

Pentafluorophenylammonium trifluoromethanesulfonimide: Mild, powerful, and robust catalyst for mukaiyama aldol and mannich reactions between ketene silyl acetals and ketones or oxime ethers

Pentafluorophenylammonium trifluoromethanesulfonimide (C6F 5N+H3·NTf2-) promotes Mukaiyama aldol and Mannich reactions using ketene silyl acetals with ketones and oxime ethers, respectively. The prese

Fluorous surface-active distannoxane catalysts

Fluorous distannoxanes (XR2fSnOSnR2 fX)2·nH2O (Rf= C 6F13C2H4) (1: X= C8F 17SO3, n= 10; 4: X = Cl, n=

Organotin perfluorooctanesulfonates as air-stable Lewis acid catalysts: Synthesis, characterization, and catalysis

The reactions of 1,3-dichloro-1,1,3,3-tetrabutyldistannoxane and di-alkyltin dihalides with silver perfluoro-octanesulfonate provided the corresponding sulfonates as hydrates. The number of water molecules (n) of hydration was dependent on the conditions. The distannoxane derivative was identified as n from 0.5 to 6, while in the hydrated mononuclear species and DMSO complexes n varied widely from 4 to 13. 119Sn NMR spectroscopy and conductivity measurements indicated the ionic dissociation of these compounds in solution. These compounds exhibited unusually high solubility in polar organic solvents. The ionic dissociation together with facile hydration probably causes the unusual solubility. The Lewis acidity of these compounds was found to be high among organotin derivatives on the basis of ESR spectra of Superoxide/ metal-ion complexes. In contrast to well-known organotin Inflates, these compounds suffered no hydrolysis upon storage in open air. The high catalytic activity of the distannoxane 1 was exemplified for various carboncarbon bond-forming reactions, such as Mukaiyama-aldol as well as -Michael reactions and allylation of aldehydes.

Strong counteranion effects on the catalytic activity of cationic silicon lewis acids in Mukaiyama aldol and Diels-Alder reactions

(Graph Presented) A toluene-coordinated silyl borate, [Et 3Si(toluene)]B(C6F5)4, demonstrated catalytic activities significantly higher than those of Me3SiOTf and Me3SiNTf2 in Mu

(2,7-Disubstituted-1,8-biphenylenedioxy)bis(dimethylaluminum) as Bidentate Organoaluminum Lewis Acids: Elucidation and Synthetic Utility of the Double Electrophilic Activation Phenomenon

A series of (2,7-disubstituted-1,8-biphenylenedioxy)bis(dimethylaluminum) (2) has been readily prepared in situ by treatment of the requisite 2,7-disubstituted-1,8-biphenylenediol (1) with Me3Al (2 equiv) in CH2Cl2 at room temperature; this primarily relies on the successful establishment of a new synthetic procedure of 1 starting from inexpensive m-anisidine. Evaluation of 2 as a bidentate organoaluminum Lewis acid has been performed by the reduction of ketonic substrates using Bu 3SnH as a hydride source in comparison to the conventional monodentate Lewis acid dimethylaluminum 2,6-xylenoxide (11), uncovering the significantly high activation ability of 2 toward carbonyl. Particularly, (2,7-dimethyl-1,8-biphenylenedioxy)-bis(dimethylaluminum) (2a) exerted the highest reactivity, which has also been emphasized in the Mukaiyama aldol reaction. The structure of the bidentate Lewis acid 2 was unambiguously determined by single-crystal X-ray diffraction analysis of 2g possessing a bulky 3,5-di-tert-butylphenyl substituent, revealing the rigid dimeric assembly in the solid state. The double electrophilic activation of carbonyl substrate by 2a has been supported by low-temperature 13C NMR analysis as well as theoretical study using the Gaussian 98 program. Moreover, unique stereoselectivity has been observed in the 2a-promoted Mukaiyama Michael addition, and highly chemoselective functionalization of carbonyl compounds in the presence of their acetal counterparts has been realized using 2a. Finally, the effectiveness of 2a for the activation of ether functionality has been demonstrated in the Claisen rearrangement of allyl vinyl ethers.

A new method for the catalytic aldol reaction to ketones

A new method for the catalytic aldol reaction to ketones, using CuF·3PPh3·2EtOH complex as the catalyst and (EtO)3SiF as the additive, is described. The reaction can be applied to a wide range of ketones and trimethylsilyl enolates. On the basis of mechanistic studies, a working hypothesis for the catalytic cycle is proposed, in which the dynamic ligand exchange mediated by copper silicates produces the active copper enolate. Moreover, the present reaction can be extended to the catalytic enantioselective reaction using tol-BINAP as a chiral ligand. Copyright

Regioselective formation of 2-alkoxyoxetanes in the photoreaction of aromatic carbonyl compounds with β,β-dimethyl ketene silyl acetals: Notable solvent and silyl group effects

Regioselective formation of 2-alkoxyoxetanes 3 was achieved in the photoreactions of aromatic ketones 2 with electron-rich ketene silyl acetals 1. In the photoreactions, the silyl-migration adduct 5 was also formed together with the oxetane 3. The product ratios of 3 and 5 were largely dependent on the solvent used and the silyl group of 1. The exclusive formation of 2-alkoxyoxetanes 3 was controlled by proper choice of the solvent and silyl group.

The chromium Reformatsky reaction: Access to adjacent quarternary centers

α-Bromo ketones, -esters and -nitriles react with chromium dichloride and ketones in a Barbier-type reaction to yield the kinetic crossed aldol products with one or two new quarternary centers. The reaction does not require special activation of the reage