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Capítulo 19

Aminas

Aminas: Introdução
Aminas: Introdução
Amines are organic derivatives of ammonia. They are formed by replacing one or more ammonia protons with alkyl or aryl groups. Depending upon the number ...
Nomenclatura de Aminas Primárias
Nomenclatura de Aminas Primárias
Primary, secondary, and tertiary amines are compounds consisting of one, two, and three alkyl groups connected to the amino group (–NH2), ...
Nomenclatura de Aminas Secundárias e Terciárias
Nomenclatura de Aminas Secundárias e Terciárias
The secondary and tertiary amines are derivatives of ammonia, where two and three of its hydrogens are replaced by alkyl groups, respectively. Secondary ...
Nomenclatura de Arilas e Aminas Heterocíclicas
Nomenclatura de Arilas e Aminas Heterocíclicas
The simplest aromatic amine is phenylamine, which contains an –NH2 functionality directly attached to an aromatic ring. The name aniline is ...
Estrutura de Aminas
Estrutura de Aminas
The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which ...
Propriedades Físicas das Aminas
Propriedades Físicas das Aminas
Amines with low molecular weight are usually gaseous at room temperature, while those with high molecular weight are liquid or solids in nature. Usually, ...
Basicidade de Aminas Alifáticas
Basicidade de Aminas Alifáticas
Amines can behave as Brønsted–Lowry bases by accepting a proton from the acid to form corresponding conjugate acids. Due to a lone pair of ...
Basicidade de Aminas Aromáticas
Basicidade de Aminas Aromáticas
The basicity of aromatic amines is much weaker than that of aliphatic amines due to the involvement of the lone pair of electrons over the N atom in ...
Basicidade de Aminas Aromáticas Heterocíclicas
Basicidade de Aminas Aromáticas Heterocíclicas
Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine ...
Espectroscopia de NMR de Aminas
Espectroscopia de NMR de Aminas
In proton NMR spectroscopy, primary amines and secondary amines showcase their N–H protons as a broad signal in the chemical shift range between ...
Espectrometria de Massa de Aminas
Espectrometria de Massa de Aminas
In mass spectroscopy, amines undergo fragmentation to give parent ions with odd molecule weights. This observed mass spectrum follows the nitrogen rule: a ...
Preparação de Aminas: Alquilação de Amônia e Aminas
Preparação de Aminas: Alquilação de Amônia e Aminas
Alkylation is one of the methods used to prepare amines. Direct alkylation of ammonia or a primary amine with an alkyl halide gives polyalkylated amines ...
Preparação de Aminas Primárias: Síntese de Azida
Preparação de Aminas Primárias: Síntese de Azida
Direct alkylation of ammonia produces polyalkylated amines, along with a quaternary ammonium salt. To exclusively prepare primary amines, the azide ...
Preparação de Aminas Primárias: Síntese de Gabriel
Preparação de Aminas Primárias: Síntese de Gabriel
Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred ...
Preparação de Aminas: Redução de Oximas e Nitro Compostos
Preparação de Aminas: Redução de Oximas e Nitro Compostos
Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and ...
Preparação de Aminas: Redução de Amidas e Nitrilas
Preparação de Aminas: Redução de Amidas e Nitrilas
Nitriles can be reduced to primary amines using reducing agents like lithium aluminum hydride or catalytic hydrogenation. The reduction introduces an ...
Preparação de Aminas: Aminação Redutiva de Aldeídos e Cetonas
Preparação de Aminas: Aminação Redutiva de Aldeídos e Cetonas
Carbonyl compounds and primary amines undergo reductive amination first to produce imines, followed by secondary amines in the same reaction mixture, ...
Preparação de Aminas Primárias: Visão Geral do Rearranjo de Hofmann e de Curtius
Preparação de Aminas Primárias: Visão Geral do Rearranjo de Hofmann e de Curtius
In the presence of an aqueous base and a halogen, primary amides can lose the carbonyl (as carbon dioxide) and undergo rearrangement to form primary ...
Preparação de Aminas Primárias: Mecanismo de Rearranjo de Hofmann e de Curtius
Preparação de Aminas Primárias: Mecanismo de Rearranjo de Hofmann e de Curtius
The Hofmann and Curtius rearrangement reactions can be applied to synthesize primary amines from carboxylic acid derivatives such as amides and acyl ...
Aminas a Amidas: Acilação de Aminas
Aminas a Amidas: Acilação de Aminas
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction ...
Aminas a Alquenos: Eliminação de Hofmann
Aminas a Alquenos: Eliminação de Hofmann
Alkenes can be obtained from amines via an E2 elimination. The amine is first converted into a good leaving group, such as a quaternary ammonium salt. ...
Aminas a Alquenos: Eliminação de Cope
Aminas a Alquenos: Eliminação de Cope
Cope elimination reaction involves the conversion of tertiary amines to alkene using hydrogen peroxide under thermal conditions, as depicted in figure 1. ...
Aminas Primárias a Sais de Diazônio ou Arildiazônio: Visão Geral da Diazotização com NaNO2
Aminas Primárias a Sais de Diazônio ou Arildiazônio: Visão Geral da Diazotização com NaNO2
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa ...
Aminas Primárias a Sais de Diazônio ou Arildiazônio: Mecanismo Diazotização com NaNO2
Aminas Primárias a Sais de Diazônio ou Arildiazônio: Mecanismo Diazotização com NaNO2
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic ...
Aminas Secundárias a N-Nitrosaminas: Reação com NaNO2
Aminas Secundárias a N-Nitrosaminas: Reação com NaNO2
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from ...
Substituição do Grupo Diazônio por Halogênios e Cianetos: Reação de Sandmeyer e de Schiemann
Substituição do Grupo Diazônio por Halogênios e Cianetos: Reação de Sandmeyer e de Schiemann
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. ...
Substituição do Grupo Diazônio: –OH e –H
Substituição do Grupo Diazônio: –OH e –H
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in ...
Sais de Arildiazônio a Corantes Azo: Acoplamento Diazo
Sais de Arildiazônio a Corantes Azo: Acoplamento Diazo
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of ...
Aminas a Sulfonamidas: O Teste de Hinsberg
Aminas a Sulfonamidas: O Teste de Hinsberg
The Hinsberg test is a method to identify primary, secondary and tertiary amines, named after its pioneer, Oscar Hinsberg. Here, amines are treated with ...
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