Mapa de potencial electrostático de la trimetilamina

Presentación del tema: "Mapa de potencial electrostático de la trimetilamina"— Transcripción de la presentación:

1 Mapa de potencial electrostático de la trimetilamina
AMINAS Figure: Caption: Ammonia has a slightly distorted tetrahedral shape, with a lone pair of non-bonding electrons occupying one of the tetrahedral positions. This geometry is represented by sp3 hybridization of nitrogen, with the bulky lone pair compressing the H-N-H bond angles to 107o from the "ideal" sp3 bond angle of 109.5o. Amoniaco Trimetilamina Mapa de potencial electrostático de la trimetilamina

2 Figure: UN Caption: Amines are strongly polar because the large dipole moment of the lone pair of electrons adds to the dipole moments of the C-N and H-N bonds.

3 OBTENCIÓN DE AMINAS POR REDUCCIÓN DE AMIDAS

4 OBTENCIÓN DE AMINAS PRIMARIAS REORDENAMIENTO DE HOFMANN
Figure: UN Caption: In the presence of strong base, primary amides react with chlorine or bromine to form shortened amines with loss of the carbonyl carbon atom. This reaction, called the Hofmann rearrangement, is used to synthesize primary and aryl amines.

5 OBTENCIÓN DE AMINAS PRIMARIAS
Figure: UN Caption: Like the azide ion, cyanide ion is a good SN2 nucleophile; it displaces leaving groups from primary or secondary alkyl halides or tosylates. The product is a nitrile, which has no tendency to react further. Nitriles are reduced to primary amines by LiAlH4 or catalytic hydrogenation.

6 OBTENCIÓN DE AMINAS POR REDUCCIÓN DE NITROCOMPUESTOS
Figure: UN Caption: Both aliphatic and aromatic nitro groups are easily reduced to amino groups. The most common methods are catalytic hydrogenation and acidic reduction by an active metal.

7 Reacción de una amina como nucleófilo
REACCIONES DE AMINAS Reacción de una amina como nucleófilo Reacción de una amina como base Figure: UN Caption: An amine is a nucleophile (a Lewis base) because its lone pair of non-bonding electrons can form with an electrophile. An amine can also acts as a Bronsted-Lowry base by accepting a proton from a proton acid.

8 REACCIÓN DE AMINAS CON ÁCIDO NITROSO
Figure: UN Caption: In an acidic solution, nitrous acid may protonate and lose water to give the nitrosonium ion, NO2+. The nitrosonium ion appears to be the reactive intermediate in most reactions of amines with nitrous acid.

9 Figure: UN Caption: Primary amines react with nitrous acid, via the nitrosonium ion, to give diazonium cations. This procedure is called diazotization of an amine.

10 Figure: UN Caption: A proton transfer (a tautomerism) from nitrogen to oxygen forms a hydroxyl group and a second N-N bond. Protonation of the hydroxyl group, followed by loss of water, gives the diazonium cation.

11 REACCIONES DE LAS SALES DE DIAZONIO
Figure: UN Caption: Arenediazonium salts are formed by diazotizing a primary aromatic ring. Primary aromatic amines are commonly prepared by nitrating an aromatic ring, then reducing the nitro group to an amino group. In effect, by forming and diazotizing and amine, an activated aromatic position can be converted into a wide variety of functional groups.

12 Figure: UN Caption: Hydrolysis takes place when a solution of an arenediazonium salt is strongly acidified (usually by adding H2SO4) and warmed.

13 REACCIÓN DE SANDMEYER Figure: 19-13-024UN Caption:
Copper(I) salts (cuprous salts) have a special affinity for diazonium salts. Cuprous chloride, cuprous bromide, and cuprous cyanide react with arenediazonium salts to give aryl chlorides, aryl bromides, and aryl cyanides.

14 ACOPLAMIENTO DIAZO: AZOCOLORANTES
Figure: UN Caption: Arenediazonium ions act as weak electrophiles in electrophilic aromatic substitutions. The products have the structure Ar-N=N-Ar, containing the -N=N- azo linkage. For this reason the products are called azo compounds, and the reaction is called diazo coupling. Anaranjado de metilo (indicador)