212968-11-1

Upstream product

• 104-94-9 4-methoxy-aniline 
• 1439-07-2 trans-Stilbene oxide 
• 1689-71-0 2,3-diphenyloxirane 
• 19339-72-1 2-((4-methoxyphenyl)amino)-1,2-diphenylethan-1-one 

Downstream Products

• 86286-50-2 (4R,5S)-4,5-diphenyl-1,3-oxazolidin-2-one 

Relevant academic research and scientific papers

Double Asymmetric Hydrogenation of α-Iminoketones: Facile Synthesis of Enantiopure Vicinal Amino Alcohols

This study presents an Rh/DuanPhos-catalyzed double asymmetric hydrogenation of α-iminoketones for accessing chiral vicinal amino alcohols, which are privileged motifs in pharmaceuticals, agrochemicals, fine chemicals, chiral auxiliaries, organocatalysts, etc. Compared with existing methods, this methodology has the following advantages, such as one-pot operation, high efficiency, operational simplicity, limited waste, broad reaction scope, and high yields (90 to 96%) and stereoselectivities (up to >99:1 dr; >99.9% ee). In addition, the mechanism of the transformation was revealed to be a stepwise reaction by isolating and analyzing reaction intermediates.

Controlled Exchange of Achiral Linkers with Chiral Linkers in Zr-Based UiO-68 Metal-Organic Framework

The development of highly robust heterogeneous catalysts for broad asymmetric reactions has always been a subject of interest, but it remains a synthetic challenge. Here we demonstrated that highly stable metal-organic frameworks (MOFs) with potentially acid-labile chiral catalysts can be synthesized via postsynthetic exchange. Through a one- or two-step ligand exchange, a series of asymmetric metallosalen catalysts with the same or different metal centers are incorporated into a Zr-based UiO-68 MOF to form single- and mixed-M(salen) linker crystals, which cannot be accomplished by direct solvothermal synthesis. The resulting MOFs have been characterized by a variety of techniques including single-crystal X-ray diffraction, N2 sorption, CD, and SEM/TEM-EDS mapping. The single-M(salen) linker MOFs are active and efficient catalysts for asymmetric cyanosilylation of aldehydes, ring-opening of epoxides, oxidative kinetic resolution of secondary alcohols, and aminolysis of stilbene oxide, and the mixed-M(salen) linker variants are active for sequential asymmetric alkene epoxidation/epoxide ring-opening reactions. The chiral MOF catalysts are highly enantioselective and completely heterogeneous and recyclable, making them attractive catalysts for eco-friendly synthesis of fine chemicals. This work not only advances UiO-type MOFs as a new platform for heterogeneous asymmetric catalysis in a variety of syntheses but also provides an attractive strategy for designing robust and versatile heterogeneous catalysts.

Synthesis of enantiopure β-amino alcohols via AKR/ARO of epoxides using recyclable macrocyclic Cr(III) salen complexes

A series of chiral macrocyclic Cr(III) salen complexes 1-8 were synthesized and characterized. These complexes were found to be highly active, regio-, diastereo-, and enantioselective catalysts in aminolytic kinetic resolution (AKR) of racemic trans-epoxides as well as asymmetric ring opening (ARO) of prochiral meso-epoxides with various anilines as nucleophiles at room temperature in 18-24 h. Excellent yields (>99% with respect to the nucleophile) with high enantioselectivity (ee, >99%) of chiral anti-β-amino alcohols was achieved with concomitant recovery of corresponding epoxides in high ee (up to >99%). The complex 1 also catalyzed the ARO of meso-epoxides to provide corresponding syn-β-amino alcohols in high yield (99%) and ee (up to 91%). Due to built-in basic sites in the catalyst, no external base (as an additive) was required to promote AKR and ARO reactions. The catalyst 1 was conveniently recycled several times with retention of its performance. The AKR of trans-stilbene oxide with aniline was successfully demonstrated at relatively higher scale (10 mmol) using the catalyst 1.

Reusable chiral dicationic chromium(III) salen catalysts for aminolytic kinetic resolution of trans-epoxides

A series of new recyclable chiral dicationic chromium(III) salen complexes 1-10 bearing different substituents, viz., hydrogen, methyl, tert-butyl, triphenylphosphinomethyl, triethylaminomethyl, methylimidazolium, methylpyridinium, methyl-N,N-dimethylpyri

Chiral recyclable dimeric and polymeric Cr(III) salen complexes catalyzed aminolytic kinetic resolution of trans-aromatic epoxides under microwave irradiation

Aminolytic kinetic resolution (AKR) of trans-stilbene oxide and trans-β-methyl styrene oxide proceeded smoothly under microwave irradiation using chiral dimeric and polymeric Cr(III) salen complexes as efficient catalysts, giving regio-, diastereo-, and enantioselective anti-β-amino alcohols in high yields (49%) and chiral purity (ee up to 94%) in case of 4-methylaniline within 2 min. The kinetic resolution system is approximately five times faster than traditional oil bath heating at 70°C and 420 times faster than the reaction conducted at room temperature with concomitant recovery of respective chirally enriched epoxides (ee, 92%) in excellent yields (up to 48%). The catalyst 1 worked well in terms of enantioselectivity than the catalyst 2, but both the catalysts were easily recovered and reused five times with the retention of its efficiency.

Enantioselective aminolytic kinetic resolution (AKR) of epoxides catalyzed by recyclable polymeric Cr(III) salen complexes

Polymeric chiral Cr(III) salen complexes catalyzed regio-, diastereo-, and enantioselective aminolytic kinetic resolution (AKR) of trans-stilbene oxide, trans-β-methyl styrene oxide, and 6-CN-chromene oxide proceeded smoothly at room temperature, providing the desired anti-β-amino alcohols in high yields and enantiomeric excess (up to 100%).

Asymmetric aminolysis of aromatic epoxides: A facile catalytic enantioselective synthesis of anti-β-amino alcohols

The first asymmetric aminolysis of trans-aromatic epoxides with anilines is described. The process affords enantioenriched anti-β-amino alcohols in up to 99% ee. The complete regio- and diastereoselectivity observed uses commercially available [Cr(Salen)CI] as a Lewis acid catalyst and in combination with a very simple experimental procedure renders the present reaction a facile and practical tool for the synthesis of chiral nonracemic anti-β-amino alcohols.