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Carbenes, reaction with

A carbene is a neutral, highly reactive molecule containing a divalent carbon with only six valence electrons. They are usually formed in one of the two ways. [Pg.94]

As carbenes are electron deficient, they can act as powerful electrophiles. At the same time, they can also be thought of acting as nucleophiles, because they contain an unshared pair of electrons. [Pg.94]

Carbenes will add to alkenes to form cyclopropanes. The mechanism of these insertion reactions depends on whether a singlet carbene (this contains a pair of reactive electrons in the same orbital) or a triplet carbene (this contains two unpaired and reactive electrons in different orbitals) adds to the double bond. [Pg.94]

Singlet carbene (concerted mechanism - stereospecific syn- addition) [Pg.94]

To form the second C-C bond, the electrons must have opposite spins [Pg.95]


Furan and thiophene undergo addition reactions with carbenes. Thus cyclopropane derivatives are obtained from these heterocycles on copper(I) bromide-catalyzed reaction with diazomethane and light-promoted reaction with diazoacetic acid ester (Scheme 41). The copper-catalyzed reaction of pyrrole with diazoacetic acid ester, however, gives a 2-substituted product (Scheme 42). [Pg.62]

Although most of the examples of [3S+2C] cycloaddition reactions with carbene complexes are referred to as 1,3-dipolar processes, we should include in this section another kind of non-dipolar transformation dealing with the reaction of pentacarbonyl(methoxymethylcarbene)chromium with a base followed by treatment with an epoxide in the presence of boron trifluoride. This reaction gives cyclic carbene complexes in a process that can be considered a [3S+2C] cycloaddition [44] (Scheme 14). [Pg.71]

The reaction of benzyne with cyclohexadiene has been known for some time 4>, but although a number of steroidal cis-dienes are readily available no reactions with arynes had been reported prior to our beginning such investigations 145>. This was somewhat surprising in view of the number of reports concerning the modification of steroids by means of reactions with carbenes 146 i49) and the known Diels-Alder reactions of steroidal dienes and trienes iso.isi). [Pg.67]

By analogy with cyclopropane formation from carbenes and C=C bonds, azo compounds might be expected to give diaziridines in their reaction with carbenes. Although acyclic ADC compounds react readily with diazoalkanes... [Pg.10]

Among typical carbon-carbon bond (C-C) formation reactions with carbenes, the cyclopropanation reaction with olefins has been well studied including its application to industrial processes. The second typical reaction of carbenes is the insertion reaction into the carbon-hydrogen bond (C-H) which seems to be a direct and efficient C-C bond forming reaction. However, its use for synthetic purpose has often been limited due to low selectivity of the reactions.3... [Pg.288]


See other pages where Carbenes, reaction with is mentioned: [Pg.518]    [Pg.859]    [Pg.59]    [Pg.61]    [Pg.63]    [Pg.65]    [Pg.67]    [Pg.69]    [Pg.71]    [Pg.73]    [Pg.75]    [Pg.77]    [Pg.1284]    [Pg.154]    [Pg.189]    [Pg.1]    [Pg.10]    [Pg.24]    [Pg.290]   
See also in sourсe #XX -- [ Pg.1086 , Pg.1087 ]




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1.3- Dienes cycloaddition reactions with alkynyl carbene

1.3- Dienes reactions with iron carbene complexes

2- Butyne reaction with iron carbene complexes

2- Pentyne reaction with carbene complexes

5-Membered rings reaction with carbenes

Acetals, reaction with carbene complexes

Acetylenedicarboxylates reactions with carbenes

Acetylenes reactions with Fischer carbene

Aldehydes reaction with nucleophilic carbenes

Alkenes reaction with carbenes

Alkenes reaction with carbenes, stereochemistry

Alkynes reaction with carbene complexes

Alkynes reaction with carbenes

Alkynes reactions with Fischer carbene complexes

Allenes reactions with Fischer carbene complexes

Amines reaction with carbene complexes

Aromatic compounds addition reactions with carbenes

Aromatic compounds reaction with carbenes

Benzene derivatives reaction with carbenes

Benzene reaction with carbenes

Benzo furan reaction with carbenes

Benzofuran reaction with carbenes

Bicyclobutane carbenes reaction with

Carbene complexes insertion reactions with

Carbene complexes reactions with carbonyl compounds

Carbene complexes reactions with nucleophiles

Carbene complexes, alkyl pentacarbonylalkylation reaction with carbonyl compounds

Carbene precursors, reaction with

Carbene reaction with alkenes

Carbene reaction with lone pairs

Carbene reaction with olefins

Carbene reactions

Carbene, dichloro-, reactions with

Carbenes and carbenoid intermediates reactions with aromatic compounds

Carbenes reaction with carbonyl

Carbenes reaction with ethers

Carbenes reaction with nitriles

Carbenes reaction with polystyrene

Carbenes reactions

Carbenes reactions with alkanes

Carbenes reactions with diynes

Carbenes reactions with enamines

Carbenes reactions with esters

Carbenes, alkynyltransition metal complexes cycloaddition reactions with 1,3-dienes

Carbenes, generation reaction with diazoalkanes

Carbenes, halo reaction with alkenes

Carbenes, reaction with alkenes, stereoselectivity

Carbenes, reaction with heterocyclic

Carbenes, reaction with heterocyclic compounds

Carbenes, reaction with indenes

Carbenes, reactions with pyridine

Coupling reactions with carbene complexes

Cyclohexene reaction with carbene

Cyclohexene reaction with carbenes

Cyclopropanes from carbene reaction with alken

Cyclopropyl carbene complexes reactions with alkenes

Diazoalkanes, reaction with carbenes

Diazoketones, carbene reactions with

Dienes reaction with carbenes

Diethyl zinc, reaction with carbenes

Dimethyl fumarate reaction with carbenes

Dimethyl maleate reaction with carbenes

Dinitrogen reaction with carbenes

Enynes reaction with Fischer carbene complexes

Ethene reaction with carbenes

Ethers, enol reaction with carbenes

Five-membered heterocycles reactions with carbenes

Heteroaromatic compounds reactions with carbenes

Heterocycles reaction with carbenes

Heterocyclic compounds reactions of, with carbenes

Hexafluorobenzene reaction with carbenes

Imines reaction with carbene complexes

Imines reactions with Fischer carbene complexes

Indole reaction with carbenes

Indole, alkyl-, reaction with carbenes

Iron complexes, carbene reactions with alkenes

Isocyanides reactions with Fischer carbene complexes

Isothiocyanates reaction with carbenes

Ketenimines reactions with Fischer carbene complexes

Metal-carbene complexes reaction with alkenes

Metal-carbene complexes reaction with ylides

Metal-carbene complexes reactions with

Methanol reaction with singlet carbene

Olefins reaction with carbenes

Organometallic compounds carbene, reactions with

Organometallic compounds carbenes, reactions with

Oxetane reaction with carbenes

Oxidation reaction with carbene complexes

Oxidation reactions with Fischer carbene complexes

Phosphorus reaction with carbene complexes

Pinacol reaction with carbenes

Pyran, dihydro-, reaction with carbenes

Pyridine reaction with singlet carbene

Pyrroles reaction with carbenes

Reaction with C2-functionalized Carbene Adducts

Reaction with Isolated Carbenes

Reaction with phosphorus carbene

Reactions of Carbenes with Nucleophiles

Reactions of Complexes with Neutral Carbene Precursors

Reactions of, with carbenes

Reactions with Atoms, Free Radicals and Carbenes

Reactions with Carbenes and Nitrenes

Reactions with alkyl pentacarbonyl carbene anions

Rhodium carbene, reactions with

Singlet carbene reaction with alkene

The Reactions of Stable Nucleophilic Carbenes with Main Group

Thiophene reaction with carbenes

With Carbenes

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