Organic Chemistry Synthesis: common types of reactions
To master organic chemistry synthesis reactions you must become familiar with some common types of chemical reactions. To name only few, reduction reactions, elimination reactions, addition reactions Diels Alder or dienne and dienophile reactions, substitution reactions, alkylation and for advance organic chemistry, aromatization reactions.
Organic reactions compose a wide variety of reactions involving compounds which have carbon as the main element in their molecular structure. In opposition to inorganic reactions, organic chemistry reactions are classified in large part by the types of the functional groups that exist within each compound. In this case the reactions are described by showing the mechanisms through which the changes take place.
Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are listed below:
- Addition reactions
- Elimination reactions
- Substitution reactions
- Redox reactions
- Rearrangement reactions
- Pericyclic reactions
The general form of the SN2 mechanism for example is as follows:
Nu..—>R1R2R3C- X ———-> Nu-C R1R2R3 + X-
Where Nu.. = nucleophile
X = leaving group (usually halide or tosylate, mesylate)
Example of hydroxide ion that acts as the nucleophile and bromine is the leaving group
This results in the inversion of the configuration because of the backside attack of the nucleophile.
The solvent type, the electrophile and the leaving group, all play an important role in this type of reaction:
Solvents: protic solvents such as water and alcohols stabilize the nucleophile so much that it will not react with substrate. Therefore, the use of a good polar aprotic solvent such as ethers and ketones and halogenated hydrocarbons is required.
Nucleophiles: A good nucleophile is required since it is involved in the rate determining step. A weak nucleophile will not efficiently attack the substrate.
Leaving groups: A good leaving group is required, such as a halide or a tosylate, since it is involved in the rate determining step (better leaving group for halogens the order is as follow: I>Br>C1>F). In organic synthesis, organic reactions are used in the construction of new organic molecules. The production of many man-made chemicals such as drugs, plastics, food additives, fabrics depend on organic reactions.
