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Catalytic asymmetric

In 1980, Katsuki and Sharpless communicated that the epoxidation of a variety of allylic alcohols was achieved in exceptionally high enantioselectivity with a catalyst derived from titanium(IV) isopropoxide and chiral diethyl tartrate. This seminal contribution described an asymmetric catalytic system that not only provided the product epoxide in remarkable enantioselectivity, but showed the immediate generality of the reaction by examining 5 of the 8 possible substitution patterns of allylic alcohols all of which were epoxidized in >90% ee. Shortly thereafter. Sharpless and others began to illustrate the... [Pg.50]

Heterocycles as ligands in asymmetric catalytic metal carbene transformations 98CRV911. [Pg.206]

Asymmetric catalytic epoxidation of allylic alcohols 93MI2. [Pg.244]

Asymmetric catalytic epoxidation of nonfunctionalized olefins 93MI3, 98MI1. [Pg.244]

Recent advances in the asymmetric catalytic reduction of ketones using chiral oxazaborolidines as ligands 98MI64. [Pg.273]

The Asymmetric Catalytic Diels-Alder Reaction Catalyzed by Base... [Pg.46]

The Asymmetric Catalytic Diek-Aider Reaction Catalyzed by Base 47... [Pg.47]

The landmark report by Winstein et al. (Scheme 3.6) on the powerful accelerating and directing effect of a proximal hydroxyl group would become one of the most critical in the development of the Simmons-Smith cyclopropanation reactions [11]. A clear syw directing effect is observed, implying coordination of the reagent to the alcohol before methylene transfer. This characteristic served as the basis of subsequent developments for stereocontrolled reactions with many classes of chiral allylic cycloalkenols and indirectly for chiral auxiliaries and catalysts. A full understanding of this phenomenon would not only be informative, but it would have practical applications in the rationalization of asymmetric catalytic reactions. [Pg.100]

The first example of asymmetric catalytic ring-opening of epoxides with sp2-hybridized carbon-centered nucleophiles was reported by Oguni, who demonstrated that phenyllithium and a chiral Schiff base ligand undergo reaction to form a stable system that can be used to catalyze the enantioselective addition of phenyllithium to meso-epoxides (Scheme 7.24) [48]. Oguni proposed that phenyllithium... [Pg.244]

Marko I. E., Evans G. R., Declercq J. P., Tinant B., Feneau-Dupont J. Asymmetric, Catalytic, Inverse Electron-Demand Diels-Alder Reactions of 3-Carboalk-oxy-2-Pyrone Derivatives Acros Org. Acta 1995 1 63 6... [Pg.316]

Both research teams then focused on optimizing their own asymmetric catalytic systems. We will describe those studies separately, although the progress of one of the groups aid the hypotheses of the other. [Pg.85]

Organic-Base Catalyzed. Asymmetric direct aldol reactions have received considerable attention recently (Eq. 8.98).251 Direct asymmetric catalytic aldol reactions have been successfully performed using aldehydes and unmodified ketones together with chiral cyclic secondary amines as catalysts.252 L-proline and 5,5-dimethylthiazolidinium-4-carboxylate (DMTC) were found to be the most powerful amino acid catalysts for the reaction of both acyclic and cyclic ketones as aldol donors with aromatic and aliphatic aldehydes to afford the corresponding... [Pg.268]

Privileged" scaffolds are often incorporated in the design of DOSs. An unprecedented asymmetric catalytic 1,3-dipolar cycloaddition... [Pg.417]

ASYMMETRIC CATALYTIC GLYOXYLATE-ENE REACTION METHYL (2R)>2 HYDROXY-4-PHENYL-4 PENTENOATE (Benzenabutanoic acid, a-hydroxy-y-methylene, methyl ester, (R)-)... [Pg.8]

ASYMMETRIC CATALYTIC GLYOXYLATE-ENE REACTIONS WITH 1,1- PISUBSTITUTED OLEFINSa... [Pg.11]

ASYMMETRIC CATALYTIC GLYOXYLATE-ENE REACTION METHYL (2R)-2-HYDROXY-4-PHENYL-4-PENTEN0ATE... [Pg.271]

Perhaps the most investigated reaction of organozinc compounds is their addition to the carbonyl group of aldehydes. A broad range of simple and functionalized diorganozincs and a great variety of aldehydes have been studied in this transformation. The reaction furnishes chiral secondary alcohols, which are essential building blocks in the synthesis of natural products and other important compounds. Recent studies of this transformation have been devoted to its asymmetric catalytic versions (Scheme 103). [Pg.383]

In parallel to the asymmetric catalytic isomerization of allylamines, [Rh(BINAP) (solvent)2]C104 is a very efficient catalyst for the isomerization of allylic alcohols.9,11 By employing 0.5mol% of the catalyst, good to excellent conversions were achieved even in the case of substrates that are more difficult to isomerize, such as allylic alcohols having two alkyl groups in the terminal position (R1 = R2 = Me) and 2-cyclohexen-l-ol (Scheme 19). [Pg.80]

Halpern, J. Asymmetric catalytic hydrogenation Mechanism and origin of en-antioselection. In Morrison, J.D. (Ed.), Asymmetric Synthesis. Academic Press, Orlando, 1985, Vol. 5, p. 41. [Pg.765]

An interesting example of the above difference is l-DOPA 4, which is used in the treatment of Parkinson s disease. The active drug is the achiral compound dopamine formed from 4 via in vivo decarboxylation. As dopamine cannot cross the blood-brain barrier to reach the required site of action, the prodrug 4 is administered. Enzyme-catalyzed in vivo decarboxylation releases the drug in its active form (dopamine). The enzyme l-DOPA decarboxylase, however, discriminates the stereoisomers of DOPA specifically and only decarboxylates the L-enantiomer of 4. It is therefore essential to administer DOPA in its pure L-form. Otherwise, the accumulation of d-DOPA, which cannot be metabolized by enzymes in the human body, may be dangerous. Currently l-DOPA is prepared on an industrial scale via asymmetric catalytic hydrogenation. [Pg.6]

TADDOL 104 and 126 afford 95-99% ee in the asymmetric addition of organozinc reagents to a variety of aldehydes. The best enantioselectivities are observed when a mixture of the chiral titanium TADDOL compound 127 and excess [Ti(OPr1)4] are employed (Scheme 2-49). The mechanism of the alkylzinc addition involves acceleration of the asymmetric catalytic process by the... [Pg.113]

Perhaps the most attractive method of introducing enantioselectivity into the Diels-Alder reaction is to use a chiral catalyst in the form of a Lewis acidic metal complex. In recent years, this area has shown the greatest progress, with the introduction of many excellent catalytic processes. Quite a number of ligand-metal combinations have been evaluated for their potential as chiral catalysts in Diels-Alder reactions. The most commonly used metals are boron, titanium, and aluminum. Copper, magnesium, and lanthanides have also been used in asymmetric catalytic Diels-Alder reactions. [Pg.279]

In the presence of a catalytic amount of chiral lanthanide triflate 63, the reaction of 3-acyl-l,3-oxazolidin-2-ones with cyclopentadiene produces Diels-Alder adducts in high yields and high ee. The chiral lanthanide triflate 63 can be prepared from ytterbium triflate, (R)-( I )-binaphthol, and a tertiary amine. Both enantiomers of the cycloaddition product can be prepared via this chiral lanthanide (III) complex-catalyzed reaction using the same chiral source [(R)-(+)-binaphthol] and an appropriately selected achiral ligand. This achiral ligand serves as an additive to stabilize the catalyst in the sense of preventing the catalyst from aging. Asymmetric catalytic aza Diels-Alder reactions can also be carried out successfully under these conditions (Scheme 5-21).19... [Pg.282]


See other pages where Catalytic asymmetric is mentioned: [Pg.249]    [Pg.50]    [Pg.51]    [Pg.15]    [Pg.129]    [Pg.1004]    [Pg.1009]    [Pg.191]    [Pg.95]    [Pg.250]    [Pg.2]    [Pg.53]    [Pg.143]    [Pg.228]    [Pg.329]    [Pg.343]    [Pg.360]    [Pg.368]    [Pg.395]    [Pg.76]    [Pg.84]    [Pg.900]    [Pg.4]    [Pg.768]    [Pg.854]    [Pg.925]   
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2-Arylacrylic acids, asymmetric catalytic

2-Arylacrylic acids, asymmetric catalytic hydrogenation

Acetamidocinnamic acids, catalytic asymmetric

Acetamidocinnamic acids, catalytic asymmetric hydrogenation

Addition reactions, Michael, catalytic asymmetric

Aldehyde catalytic asymmetric

Aldehydes direct catalytic asymmetric aldol

Aldol additions, catalytic asymmetric

Aldol catalytic asymmetric

Aldol reaction, direct catalytic asymmetric

Aldolase antibodies, catalytic asymmetric

Aldolases direct catalytic asymmetric aldol

Alkenes catalytic asymmetric epoxidation

Alkenes catalytic asymmetric nitrone reactions

Amino acids catalytic asymmetric synthesis

Antibodies catalytic asymmetric synthesis

Asymmetric Catalytic Desymmetrization

Asymmetric Catalytic Hydrogenation of a-Acetamidocinnamic Acid Esters

Asymmetric amplification catalytic reactions

Asymmetric catalytic aldol reactions

Asymmetric catalytic carbomagnesations

Asymmetric catalytic cycle

Asymmetric catalytic decomposition

Asymmetric catalytic deprotonation

Asymmetric catalytic growth

Asymmetric catalytic hydrogenation enamides

Asymmetric catalytic osmylation

Asymmetric catalytic racemization

Asymmetric catalytic reaction

Asymmetric catalytic sites

Asymmetric condensation catalytic activity

Asymmetric epoxidation catalytic cycle

Asymmetric epoxidation catalyzed by novel azacrown ether-type chiral quaternary ammonium salts under phase-transfer catalytic conditions

Asymmetric epoxidation under phase-transfer catalytic

Asymmetric hydrogenation catalytic cycle

Asymmetric reactions alkylation, catalytic

Asymmetric reactions catalytic 1,3-dipolar cycloadditions

Asymmetric reactions catalytic hydrogenation

Asymmetric transfer hydrogenation catalytic properties

Asymmetric transfer hydrogenation catalytic properties and mechanism

Aziridination catalytic asymmetric

BINAP ligands, Noyori catalytic asymmetric

BINAP ligands, Noyori catalytic asymmetric hydrogenation

Baeyer catalytic asymmetric

Carbonyl catalytic asymmetric epoxidation

Carbonyl compounds catalytic asymmetric reactions

Catalysts aldol additions, catalytic asymmetric

Catalytic Asymmetric 1,2-Addition Reactions

Catalytic Asymmetric 1,3-Dipolar Cycloaddition Reactions

Catalytic Asymmetric Addition of sp Hybridized Carbanions

Catalytic Asymmetric Allylation of Imines

Catalytic Asymmetric Allylations

Catalytic Asymmetric Aza Diels-Alder Reactions Promoted by Chiral Ytterbium Catalysts

Catalytic Asymmetric Baeyer-Villiger Reactions

Catalytic Asymmetric Cycloaddition Reactions

Catalytic Asymmetric Dialkylzinc Additions

Catalytic Asymmetric Epoxide Ring-opening Chemistry

Catalytic Asymmetric Induction with Chiral Lewis Acids

Catalytic Asymmetric Induction with Chiral Lewis Bases

Catalytic Asymmetric Induction with Chiral Thiols

Catalytic Asymmetric Induction with Chiral Thioureas

Catalytic Asymmetric Induction with Proline Derivatives

Catalytic Asymmetric Mukaiyama-Aldol Reactions

Catalytic Asymmetric Multicomponent Reactions

Catalytic Asymmetric Nucleophilic Addition to Achiral Imines

Catalytic Asymmetric Olefin Metathesis

Catalytic Asymmetric Pictet-Spengler Reaction

Catalytic Asymmetric Synthesis Sharpless Oxidations of Allylic alcohols

Catalytic Asymmetric Synthesis of

Catalytic asymmetric Diels-Alder

Catalytic asymmetric Diels-Alder catalyzed

Catalytic asymmetric Diels-Alder reaction

Catalytic asymmetric Heck reaction

Catalytic asymmetric Michael addition

Catalytic asymmetric Michael reaction

Catalytic asymmetric addition

Catalytic asymmetric additions, aldehydes

Catalytic asymmetric alkenylations, aldehydes

Catalytic asymmetric alkylation

Catalytic asymmetric alkylation of imines

Catalytic asymmetric allenylation

Catalytic asymmetric allylation

Catalytic asymmetric allylation chiral amide

Catalytic asymmetric allylic alkylation

Catalytic asymmetric anhydrous epoxidation

Catalytic asymmetric arylation

Catalytic asymmetric cross-coupling reactions

Catalytic asymmetric cross-coupling reactions with secondary alkyl halides

Catalytic asymmetric cyanation

Catalytic asymmetric cyanohydrin

Catalytic asymmetric cyanosilylation

Catalytic asymmetric cyanosilylation of aldehydes

Catalytic asymmetric cyanosilylation of ketones

Catalytic asymmetric cyclization

Catalytic asymmetric cycloadditions

Catalytic asymmetric cyclopropanation

Catalytic asymmetric dihydroxylation

Catalytic asymmetric enamine aldol

Catalytic asymmetric epoxidation

Catalytic asymmetric halocyclization

Catalytic asymmetric hydrogenation

Catalytic asymmetric hydrosilylation

Catalytic asymmetric inverse-electron-demand

Catalytic asymmetric inverse-electron-demand Diels-Alder reaction

Catalytic asymmetric method

Catalytic asymmetric nitroaldol reaction

Catalytic asymmetric oxidation

Catalytic asymmetric phase-transfer

Catalytic asymmetric phase-transfer Mannich-type reaction

Catalytic asymmetric phase-transfer Michael addition

Catalytic asymmetric phase-transfer alkylation

Catalytic asymmetric reactions Keck allylation reaction

Catalytic asymmetric reactions Mitsunobu reaction

Catalytic asymmetric reactions examples

Catalytic asymmetric reduction

Catalytic asymmetric synthesis

Catalytic asymmetric synthesis enantioselectivity

Catalytic asymmetric synthesis enzyme selection

Catalytic asymmetric synthesis evolution

Catalytic asymmetric synthesis gram-scale syntheses

Catalytic asymmetric synthesis overview

Catalytic asymmetric synthesis reaction

Catalytic asymmetric synthesis synthetic applications

Catalytic asymmetric synthesis, production

Catalytic asymmetric transfer

Catalytic asymmetric transfer hydrogenation

Catalytic asymmetrical induction

Catalytic chemical asymmetric sulfoxidation

Catalytic cycle asymmetric dihydroxylation reaction

Catalytic cycle of asymmetric

Catalytic hydrogenation asymmetric reduction

Catalytic reactions Sakurai allylation reaction, asymmetric

Catalytic reactions involving asymmetric

Catalytic reactions involving asymmetric reduction

Chiral monophosphine catalytic asymmetric hydrogenation

Copper catalyzed catalytic asymmetric

Cyanations catalytic asymmetric

Cycloaddition catalytic asymmetric

Cycloaddition catalytic asymmetric 1,3-dipolar

Darzens catalytic asymmetric

Diazo compounds catalytic asymmetric reactions

Diels Catalytic asymmetric promoted

Diels catalytic asymmetric

Diisopropyl catalytic asymmetric reactions

Diphosphine, Noyori catalytic asymmetric

Dynamic catalytic asymmetric

Dynamic catalytic asymmetric transformation

Enamides, Noyori catalytic asymmetric

Enamides, Noyori catalytic asymmetric hydrogenation

Enamides, asymmetric catalytic

Enantioselectivity catalytic asymmetric nitrone reactions

Enantioselectivity catalytic asymmetric reactions

Enones catalytic asymmetric epoxidation

Epoxidations, catalytic asymmetric

Friedel catalytic asymmetric

Halogenation catalytic asymmetric

Homogeneous asymmetric catalytic hydrogenation

Hydroalumination catalytic asymmetric

Hydroboration catalytic asymmetric

Hydrogenation, catalytic, alkene asymmetric catalysts

Imine catalytic asymmetric reduction

Iminium salt-mediated catalytic asymmetric

Iminium salt-mediated catalytic asymmetric epoxidation

Indoles asymmetric catalytic synthesis

Intermolecular catalytic asymmetric alkylations

Ketones Noyori catalytic asymmetric hydrogenation

Ketones catalytic asymmetric

Lewis acids catalytic asymmetric 1,3-dipolar cycloadditions

Magnesium complexes, catalytic asymmetric

Metathesis catalytic asymmetric

Michael catalytic asymmetric

Mukaiyama catalytic asymmetric

Nitroaldol reaction, anti-selective catalytic asymmetric

Nitrones catalytic asymmetric 1,3-dipolar

Noyori catalytic asymmetric hydrogenation mechanism

Nucleophiles catalytic asymmetric addition

Olefin , catalytic asymmetric arylation

Olefin dihydroxylation, catalytic asymmetric

Olefin hydrogenation, catalytic asymmetric

Organic synthesis catalytic asymmetric

Origins of enantioselectivity in catalytic asymmetric synthesis

Oxazolidinone derivatives, catalytic asymmetric

Palladium complexes, catalytic asymmetric

Pauson-Khand reaction catalytic asymmetric

Practical asymmetric catalytic

Practical asymmetric catalytic reactions

Racemization Noyori catalytic asymmetric hydrogenation

Rate Enhancement of Catalytic Asymmetric Reactions by Silver(I) Salts

Reactions catalytic asymmetric epoxidation

Recent Advances in Catalytic Asymmetric Desymmetrization Reactions

Rhodium catalytic compounds asymmetric reactions

Rhodium complexes Noyori catalytic asymmetric hydrogenation

Ruthenium complexes, Noyori catalytic asymmetric hydrogenation

Sharpless asymmetric dihydroxylation Catalytic cycle

Sharpless catalytic asymmetric aminohydroxylation

Shibasaki direct catalytic asymmetric

Shibasaki direct catalytic asymmetric aldol reaction

Strecker catalytic asymmetric

Strecker reaction, catalytic asymmetric

Supercritical catalytic asymmetric hydrogenations

Vinylation asymmetric catalytic

Wittig Reaction catalytic asymmetric

Ytterbium catalytic asymmetric Diels-Alder reaction

Ytterbium complexes, catalytic asymmetric

Zinc catalysts direct catalytic asymmetric aldol

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