771476-47-2

Upstream product

• 590-86-3 isovaleraldehyde 
• 1119-16-0 isocaproic aldehyde 
• 586-96-9 Nitrosobenzene 

Downstream Products

• 57333-96-7 tacalcitol 
• 188949-02-2 1α-[(tert-butyldimethylsilyl)oxy]-24R-[(methoxymethyl)oxy]-vitamin D₃ tert-butyldimethylsilyl ether 

Relevant academic research and scientific papers

Organocatalyst Efficiency in the α-Aminoxylation and α-Hydrazination of Carbonyl Derivatives in Aqueous Media or in a Ball-Mill

Pyrrolidine-derived organocatalysts have been tested in two types of α-heterofunctionalization reactions in aqueous media or under solvent-free ball-milling conditions. The best results in terms of both activity and enantioselectivity were obtained with O

Modified Julia olefination and α aminoxylation reactions mediated convergent synthesis of 1α, 24 (R)-dihydroxyvitamin D3 (tacalcitol)

A convergent synthesis of tacalcitol has been achieved starting from inexpensive and commercially available isovaleraldehyde and easily available Inhoffen-Lythgoe diol. Key steps include a proline catalyzed α aminoxylation and a Julia-Kocienski olefination.

Prolinate Salts as Catalysts for α-Aminoxylation of Aldehyde and Associated Mechanistic Insights

Potassium and tetrabutylammonium prolinate salts are efficient catalysts in the α-aminoxylation reaction of aldehydes and nitrosobenzene, to afford synthetically useful chiral α-aminoxylated aldehydes in nearly enantiomerically pure form. This is the first reaction in which prolinate is more reactive and enantioselective than proline. Because of its higher reactivity, the catalyst loading can be reduced. A reaction mechanism involving the activation of nitrosobenzene through N-protonation of a hydrogen-bonded water molecule is proposed.

Bronsted acid assisted regio- and enantioselective direct o-nitroso aldol reaction catalysed by α,α-diphenylprolinol trimethylsilyl ether

In the presence of p-nitrobenzoic acid, the O-nitroso aldol reaction of nitrosobenzene with enolisable aldehydes may be promoted by commercially available α,α-diphenylprolinol trimethylsilyl ether. The reaction proceeds with good yields and essentially complete enantioselectivity, with catalyst loadings in the 510 mol % range. The resulting α-oxyaldehyde adducts may be transformed in situ into α-oxyimines, which provide 1,2-amino alcohols upon treatment with Grignard reagents, in good overall yield (45-59%) and with typical diastereomeric ratios ≥ 95:5.

Enantioselectivity switch in direct asymmetric aminoxylation catalyzed by binaphthyl-based chiral secondary amines

Binaphthyl-based amino acids (S)-1 and an aminosulfonamide (S)-2 were applied for direct asymmetric aminoxylation with nitrosobenzene. In the presence of either (S)-1 or (S)-2, the aminoxylation of aldehydes proceeded smoothly, and subsequent reduction wi

Direct asymmetric aminoxylation reaction catalyzed by a binaphthyl-based chiral amino sulfonamide with high catalytic performance

A binaphthyl-based amino sulfonamide (S)-2 was applied to the direct asymmetric aminoxylation of aldehydes with nitrosobenzene. The reaction catalyzed by (S)-2 proceeded smoothly to give the aminoxylated product in good yield with excellent enantioselectivity. This method represents a rare example of the highly enantioselective aminoxylation by a non-proline type catalyst with high catalytic performance.

Direct asymmetric aminoxylation reaction catalyzed by axially chiral amino acids

Binaphthyl-based amino acids were prepared and applied for the direct asymmetric aminoxylation of aldehydes with nitrosobenzene. The reaction catalyzed by (S)-1e proceeded smoothly to give the aminoxylated product in good yield and enantioselectivity. Thi

The direct catalytic asymmetric α-aminooxylation reaction: Development of stereoselective routes to 1,2-diols and 1,2-amino alcohols and density functional calculations

Proline-catalyzed direct asymmetric α-aminooxylation of ketones and aldehydes is described. The proline-catalyzed reactions between unmodified ketones or aldehydes and nitrosobenzene proceeded with excellent diastereo- and enantioselectivities. In all cases tested, the corresponding products were isolated with > 95% ees. Methyl alkyl ketones were regiospecifically oxidized at the methylene carbon atom to afford enantiomerically pure α-aminooxylated ketones. In addition, cyclic ketones could be α,α′-dioxidized with remarkably high selectivity, furnishing the corresponding diaminooxylated ketones with > 99% ees. The reaction mechanism of the proline-catalyzed direct asymmetric α-aminooxylation was investigated, and we performed density functional theory (DFT) calculations in order to investigate the nature of the plausible transition states further. We also screened other organocatalysts for the asymmetric α-oxidation reaction and found that several proline derivatives were also able to catalyze the transformation with excellent enantioselectivities. Moreover, stereoselective routes for the synthesis of monoprotected vicinal diols and hydroxyketones were found. In addition, short routes for the direct preparation of enantiomerically pure epoxides and 1,2-amino alcohols are presented. The direct catalytic α-oxidation is also a novel route for the stereoselective preparation of β-adrenoreceptor antagonists.