344791-02-2

Upstream product

• 74844-91-0 1-tert-butyl 2-methyl (2S,4R)-4-hydroxy-1,2-pyrrolidinedicarboxylate 
• 100-58-3 phenylmagnesium bromide 
• 13726-69-7 (2S,4R)-4-hydroxy-1-[(2-methylpropan-2-yl)oxycarbonyl]pyrrolidine-2-carboxylic acid 
• 33996-30-4 trans-4-hydroxy-L-proline ethyl ester hydrochloride 
• 51-35-4 4R-4-hydroxyproline 
• 24424-99-5 di-tert-butyl dicarbonate 
• 1173184-14-9 trans-4-hydroxy-α,α-diphenyl-L-prolinol hydrochloride 
• 100-59-4 phenylmagnesium chloride 

Downstream Products

• 1198800-73-5 3-(5-((3R,5S)-5-(hydroxydiphenylmethyl)pyrrolidin-3-yloxy)-5-oxopentyl)-1-methyl-1H-imidazol-3-ium bromide 
• 1218989-18-4 (6R,7aS)-1,1-diphenyl-6-(prop-2-yn-1-yloxy)tetrahydro-1H,3H-pyrrolo[1,2-c]oxazol-3-one 
• 1218989-19-5 ((2S,4R)-diphenyl-4-(prop-2-yn-1-yloxy)pyrrolidin-2-yl)methanol 
• 845965-30-2 (6R,7aS)-6-Hydroxy-1,1-diphenyl-tetrahydro-pyrrolo[1,2-c]oxazol-3-one 

Relevant academic research and scientific papers

The chemzyme membrane reactor in the fine chemicals industry

Recovery of catalysts from homogeneous reaction mixtures is a major problem in the fine chemicals industry if the amount or the price of catalyst are not negligible. Product purification costs and catalyst costs are the main reasons for attempts to immobilise homogeneous catalyst, on inorganic supports or resins. We present a way to recycle the homogeneous catalyst in situ by binding it to homogeneous, soluble polymers, which can be retained by a membrane reactor system. Different research areas, which are contributing to the system, are discussed, and continuous processes on lab scale are presented.

Re-visiting the diastereoselectivity of organocatalytic conjugate addition of 2-trimethylsiloxyfuran to trans-crotonaldehyde

We describe the re-assignment of configuration previously ascribed to product diastereomers resultant from imidazolidinone-catalyzed conjugate addition of 2-trimethylsiloxyfuran to trans-crotonaldehyde. A modified procedure that uses a diphenylprolinol catalyst was subsequently developed to selectively provide the ‘syn’ diastereomeric product in high enantiomeric excess on decagram scales.

Recyclable and reusable chiral α, α-L-diaryl prolinol heterogeneous catalyst grafting to UiO-67 for enantioselective hydration/aldol/oxa-Diels Alder domino reaction

α,α-L-Diaryl prolinol was first introduced into a highly stable porous MOF, UiO-67, via the immobilization of a chiral prolinol side chain into 4,4′-biphenyldicarboxylic acid through a five-step process, to construct a chiral heterogeneous catalyst. The catalyst exhibited high yield (up to 88%) and excellent stereoselectivities (up to >4:1 dr, > 80% ee) for the enantioselective hydration/aldol/oxa-Diels Alder domino reactions, as well as good reusability with recycle use for three times without significant loss of activity. To our knowledge, this is the first report of chiral MOFs as heterogeneous catalysts for asymmetric domino reactions.

Polymer-Supported Chiral Cis-Disubstituted Pyrrolidine Catalysts and Their Application to Batch and Continuous-Flow Systems

Polymer-supported cis-pyrrolidine catalysts were developed that allowed for high enantioselectivity and diastereoselectivity compared with those obtained from common trans-pyrrolidine catalysts. Not only configurational but also polymeric effects contribute to the high diastereoselectivity and enantioselectivity. Polymer catalysts were also successfully applied in a continuous-flow process. Acceleration of the reaction rate, an increase in diastereoselectivity, and an improvement in durability were observed in continuous-flow operation compared with the batch system.

Organocatalytic Enantioselective Continuous-Flow Cyclopropanation

A set of six solid-supported diarylprolinol catalysts (varying on the anchoring strategy and the type of polymeric support) has been prepared and applied to the enantioselective cyclopropanation reaction. The selected candidate allows implementation of a long flow experiment (48 h) and generates a library of 12 cyclopropanes by sequential flow experiments. The mildness and utility of the method have enabled a telescoped process in which the outstream is directly used in a Wittig flow reaction.

Asymmetric reduction of ketones catalyzed by α,α-diphenyl-(L)-prolinol modified with imidazolium ionic liquid and BH3·SMe2 as a recoverable catalyst

The synthesis of α,α-diphenyl-4-trans-hydroxy-(L)-prolinol modified with imidazolium based ionic liquids was carried out with trans-α,α-diphenyl-4-hydroxy-(L)-prolinol, 5-bromovaleric acid or 1,5-dibromopentane and imidazole. α,α-Diphenyl-4-hydroxy-(L)-prolinol modified with imidazolium ionic liquid was treated with BH3·SMe2 which generate 1,3,2-oxazaborolidine, that acts as a catalyst for asymmetric reduction of prochiral ketones. α,α-Diphenyl-4-hydroxy-(L)-prolinol modified with imidazolium ionic liquids (PF6 anion) with BH3?SMe2 found to be an efficient catalyst (10 mol%) for the reduction of the acetophenone, gave 99% yield and 87-84% ee. The catalytic method has wide applicability for a variety of substrates. 1,3,2-oxazaborolidine containing ether linkage ionic liquid was recovered and reused up to 4 cycles with 99-91% yields and 87-81% ee's.

Immobilization of oligostyrene-prolinol conjugates into polystyrene via electrospinning and applications of these fibers in catalysis

This paper reports the synthesis of prolinol-oligostytrene conjugates and their immobilization into a polystyrene matrix by using the electrospinning process. Via this approach fibers with a large surface area (fiber diameter of 1.2 μm) containing the pro