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Cycloadditions 1,3-dipolar reactions

Keywords Diels-Alder reactions, dipolar cycloadditions, electrocyclic reactions, ene reactions, pericyclic reactions, sigmatropic rearrangements... [Pg.308]

Dipolar addition is closely related to the Diels-Alder reaction, but allows the formation of five-membered adducts, including cyclopentane derivatives. Like Diels-Alder reactions, 1,3-dipolar cycloaddition involves [4+2] concerted reaction of a 1,3-dipolar species (the An component and a dipolar In component). Very often, condensation of chiral acrylates with nitrile oxides or nitrones gives only modest diastereoselectivity.82 1,3-Dipolar cycloaddition between nitrones and alkenes is most useful and convenient for the preparation of iso-xazolidine derivatives, which can then be readily converted to 1,3-amino alcohol equivalents under mild conditions.83 The low selectivity of the 1,3-dipolar reaction can be overcome to some extent by introducing a chiral auxiliary to the substrate. As shown in Scheme 5-51, the reaction of 169 with acryloyl chloride connects the chiral sultam to the acrylic acid substrate, and subsequent cycloaddition yields product 170 with a diastereoselectivity of 90 10.84... [Pg.308]

Bis(oxazoline)-type complexes, which have been found useful for asymmetric aldol reactions, Diels-Alder, and hetero Diels-Alder reactions can also be used for inducing 1,3-dipolar reactions. Chiral nickel complex 180, which can be prepared by reacting equimolar amounts of Ni(C10)4 6H20 and the corresponding (J ,J )-4,6-dibenzofurandiyl-2,2 -bis(4-phenyloxazoline) (DBFOX/Ph) in dichloromethane, can be used for highly endo-selective and enantioselective asymmetric nitrone cycloaddition. The presence of 4 A molecular sieves is essential to attain high selectivities.88 In the absence of molecular sieves, both the diastereoselectivity and enantioselectivity will be lower. Representative results are shown in Scheme 5-55. [Pg.311]

Another theoretical investigation deals with the intramolecular [3+2] dipolar cycloaddition (Huisgen reaction) of azides and nitriles (Scheme 2) to form tetrazoles <2003JOC9076>. [Pg.352]

Grigg and co-workers (383) found that chiral cobalt and manganese complexes are capable of inducing enantioselectivity in 1,3-dipolar cycloadditions of azomethine ylides derived from arylidene imines of glycine (Scheme 12.91). This work was published in 1991 and is the first example of a metal-catalyzed asymmetric 1,3-dipolar cycloaddition. The reaction of the azomethine yhde 284a with methyl acrylate 285 required a stoichiometric amount of cobalt and 2 equiv of the chiral ephedrine ligand. Up to 96% ee was obtained for the 1,3-dipolar cycloaddition product 286a. [Pg.885]


See other pages where Cycloadditions 1,3-dipolar reactions is mentioned: [Pg.241]    [Pg.141]    [Pg.432]    [Pg.429]    [Pg.99]    [Pg.108]    [Pg.119]    [Pg.133]    [Pg.2]    [Pg.756]    [Pg.829]    [Pg.948]    [Pg.7]    [Pg.12]    [Pg.603]    [Pg.675]   
See also in sourсe #XX -- [ Pg.190 ]

See also in sourсe #XX -- [ Pg.190 ]




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1,2,3 triazole 1,3-dipolar cycloaddition reactions

1,3-dipolar cycloaddition reactions (DCRs

1,3-dipolar cycloaddition reactions 1,3-dipole

1,3-dipolar cycloaddition reactions Diels—Alder reaction

1,3-dipolar cycloaddition reactions aliphatic nitrile oxides

1,3-dipolar cycloaddition reactions classification

1,3-dipolar cycloaddition reactions cyclic nitrones

1,3-dipolar cycloaddition reactions cycloadduct

1,3-dipolar cycloaddition reactions diazomethane

1,3-dipolar cycloaddition reactions electron-deficient dipolarophiles

1,3-dipolar cycloaddition reactions from primary nitro compounds

1,3-dipolar cycloaddition reactions furoxans

1,3-dipolar cycloaddition reactions interaction

1,3-dipolar cycloaddition reactions nature

1,3-dipolar cycloaddition reactions reactivity

1,3-dipolar cycloaddition reactions salts

1,3-dipolar cycloaddition reactions unsymmetrical alkene

1,3-dipolar cycloaddition reactions with nitrile imines

1,3-dipolar cycloaddition reactions with nitrile oxides

1,3-dipolar cycloaddition reactions with nitrile ylides

1,3-dipolar cycloaddition reactions with nitrones

1,3-dipolar cycloaddition reactions with ozone

1,3-dipolar cycloaddition reactions, use

1.3 dipolar cycloaddition reaction of nitrones

1.3- Dipolar cycloaddition Tandem reactions involving

1.3- Dipolar cycloaddition reactions absolute stereoselection

1.3- Dipolar cycloaddition reactions activities

1.3- Dipolar cycloaddition reactions alkaloids

1.3- Dipolar cycloaddition reactions alkyl azides

1.3- Dipolar cycloaddition reactions azides

1.3- Dipolar cycloaddition reactions azomethine imines

1.3- Dipolar cycloaddition reactions carbonyl ylides

1.3- Dipolar cycloaddition reactions chemistry

1.3- Dipolar cycloaddition reactions cyano group

1.3- Dipolar cycloaddition reactions frontier molecular orbital theory

1.3- Dipolar cycloaddition reactions heating azide

1.3- Dipolar cycloaddition reactions intermolecular

1.3- Dipolar cycloaddition reactions isomiinchnone

1.3- Dipolar cycloaddition reactions ketone

1.3- Dipolar cycloaddition reactions mechanism

1.3- Dipolar cycloaddition reactions mesoionic systems

1.3- Dipolar cycloaddition reactions natural products

1.3- Dipolar cycloaddition reactions nitrile oxides

1.3- Dipolar cycloaddition reactions nitrones

1.3- Dipolar cycloaddition reactions nonconcerted

1.3- Dipolar cycloaddition reactions reaction

1.3- Dipolar cycloaddition reactions relative stereoselection

1.3- Dipolar cycloaddition reactions stepwise mechanism

1.3- Dipolar cycloaddition reactions stereospecificity

1.3- Dipolar cycloaddition reactions synthetic equivalents

1.3- Dipolar cycloaddition reactions tetrahydroisoquinolines

1.3- Dipolar cycloaddition reactions with alkene

1.3- Dipolar cycloaddition reactions, solvent

1.3- Dipolar cycloaddition reactions, solvent effects

1.3- Dipolar cycloadditions alkene reactions

1.3- Dipolar cycloadditions asymmetric reaction selectivity

1.3- Dipolar cycloadditions fullerene reactions

1.3- Dipolar reactions

1.3- dipolar cycloaddition reactions 1,3-DPCAs)

1.3- dipolar cycloaddition reactions HOMO-LUMO interaction

1.3- dipolar cycloaddition reactions base-catalyzed formation

1.3- dipolar cycloaddition reactions catalysis

1.3- dipolar cycloaddition reactions diazomethane preparation

1.3- dipolar cycloaddition reactions dipolarophile

1.3- dipolar cycloaddition reactions dominant frontier orbitals

1.3- dipolar cycloaddition reactions electron-rich alkenes

1.3- dipolar cycloaddition reactions examples

1.3- dipolar cycloaddition reactions intramolecular generation

1.3- dipolar cycloaddition reactions molecular orbitals

1.3- dipolar cycloaddition reactions regiochemistry

1.3- dipolar cycloaddition reactions regioselective addition

1.3- dipolar cycloaddition reactions solved problems

1.3- dipolar cycloaddition reactions stereochemistry

1.3- dipolar cycloaddition reactions substituted aziridines

1.3- dipolar cycloaddition reactions sydnones

1.3- dipolar cycloaddition reactions synchronicity

1.3- dipolar cycloaddition reactions with azides

1.3- dipolar cycloaddition reactions with azomethine imines

1.3- dipolar cycloaddition reactions with azomethine yhdes

1.3- dipolar cycloaddition reactions with carbonyl ylides

1.3- dipolar cycloaddition reactions with diazoalkanes

Asymmetric reactions 1,3-dipolar cycloaddition selectivity

Asymmetric reactions 1,3-dipolar cycloadditions

Asymmetric reactions catalytic 1,3-dipolar cycloadditions

Azomethine ylides 1,3-dipolar cycloaddition reactions

Azomethine, 1,3 dipolar cycloaddition reaction

Catalytic Asymmetric 1,3-Dipolar Cycloaddition Reactions

Cycloaddition reactions 1,3-dipolar

Cycloaddition reactions 1,3-dipolar

Cycloaddition reactions 1,3-dipolar additions

Cycloaddition reactions 1,3-dipolar cycloadditions

Cycloaddition reactions dipolar properties

Diazo 1,3-dipolar cycloaddition reaction

Diels-Alder reaction 1, 3-dipolar cycloaddition

Diels-Alder reaction 1,3-dipolar cycloadditions

Diels-Alder reactions and 1,3-dipolar cycloadditions

Dipolar Cycloaddition Reactions in Peptide Chemistry

Dipolar Cycloaddition-Based Multicomponent Reactions

Dipolar cycloaddition reactions enantioselective

Dipolar cycloaddition reactions intramolecular

Dipolar cycloaddition reactions regioselectivity

Dipolar cycloaddition reactions stereoselectivity

Dipolarophiles, in 1,3-dipolar cycloaddition reactions

Enantioselective catalysts dipolar cycloaddition reactions

External reagents, 1,3-dipolar cycloaddition enantioselective reactions

External reagents, 1,3-dipolar cycloaddition magnesium ion-mediated reactions

External reagents, 1,3-dipolar cycloaddition reaction mechanisms

External reagents, 1,3-dipolar cycloaddition reactions

Five-membered heterocycles 1,3-dipolar cycloaddition reactions

Formation of five-membered rings - 1,3-dipolar cycloaddition reactions

Functionalization dipolar cycloaddition reactions

Heck reactions 1,3-dipolar cycloadditions

Huisgen 1,3-dipolar cycloaddition reaction

Intramolecular dipolar cycloaddition reactions of azomethine ylides

Ketones nitrone 1,3-dipolar cycloadditions, reaction

Mukaiyama 1.3- dipolar cycloaddition reaction with

New Reactions of Copper Acetylides Catalytic Dipolar Cycloadditions and Beyond

Nitrone reactions with cyclopropanes 3+2]dipolar cycloaddition

Nitrones 1,3-dipolar cycloaddition reactions, external

Of 1,3-dipolar cycloaddition reactions

Oxazolidinones 1,3-dipolar cycloaddition reactions

Peptides 1,3-dipolar cycloaddition reactions

Polymers, 1,3-dipolar cycloaddition reactions

Porphyrins in Diels-Alder and 1,3-dipolar cycloaddition reactions

Pyrazolines from dipolar cycloaddition reactions

Reduction-1,3-dipolar cycloaddition reaction

Rhodium(ll)-Catalyzed 1,3-Dipolar Cycloaddition Reactions

Stereoselective reactions 1,3-dipolar cycloaddition

Stereoselective reactions 1,3-dipolar cycloadditions

Stereospecific reactions 1.3- dipolar cycloaddition

Synthesis of Nitrogen Heterocycles via Pd-Catalyzed 1,3-Dipolar Cycloaddition Reactions

Typical 1,3-dipolar cycloaddition reactions

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