Chiral oxazolidinone ketone catalyst

Although ketone 62 is an effective epoxidation catalyst for a variety of trans- and trisubstituted olefins, epoxidation of cis- and terminal olefins using this ketone led to rather poor enantioselectivity." " To improve the performance of asymmetric epoxidation of other types of olefins, a new class of chiral oxazolidinone ketone catalysts was explored (Scheme 35.17)." ° High enantioselectivity was obtained for asymmetric epoxidation of cis- and terminal olefins with ketones 65" and 66, respectively. 

Precursor of Useful Chiral Ligands. OPEN is widely used for the preparation of chiral ligands. Organometallic compounds with these ligands act as useful reagents or catalysts in asymmetric induction reactions such as dihydroxylation of olefins, transfer hydrogenation of ketones and imines, Diels-Alder and aldol reactions, desymmetrization of meso-diols to produce chiral oxazolidinones, epoxidation of simple olefins, benzylic hydroxylation, and borohydride reduction of ketones, imines, and a,p-unsaturated carboxylates. ... 

An intriguing procedure-controlled enantioselectivity switch was observed when using a single cinchona-alkaloid-derived organocatalyst 184 (or similar) to realize a formal [3 + 2] cycloaddition between TsNCO and Y-hydroxy-a,P-unsaturated ketones 183 to afford chiral oxazolidinones 182. An opposite enantioselectivity was experienced, depending on the sequence in which the reactant and the catalyst are mixed. Although this... 

Diels-Alder reactions of (Z)-A -substituted-4-methylene-5-propylidene-2-oxazoli-dinone dienes with methyl vinyl ketone, methyl propiolate, and captodative alkenes yield the highest regio- and stereo-selectivities in mixtures of H20 and MeOH or under BF3.Et20 catalysis.198 The asymmetric Diels-Alder reaction of cyclopentadiene and 3-acryloyl-2-oxazolidinone is catalysed by a new Cu(II) catalyst containing a chiral sterically congested roofed (2-diphenylphosphino)phenylthiazoline ligand (169).199... 

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