Organic chemistry substitution reaction

This type of reactions are very common in organic chemistry (substitution reaction). For example the chlorination of methane may give mono, di, tri and/or tetra halogen derivative. 

The basic concepts of nucleophilic substitution reactions appeared in the first semester of organic chemistry. These reactions follow or Sp 2 mechanisms. (In aromatic nucleophilic substitution mechanism, we use the designation Sp Ar.) In Sfjl and Sp 2 mechanisms, a nucleophile attacks the organic species and substitutes for a leaving group. In aromatic systems, the same concepts remain applicable, but with some differences that result from the inherent stability of aromatic systems. 

Diels-Alder reactions have long played an important role in synthetic organic chemistry. The reaction of a substituted benzoquinone and 1,3-butadiene, for example, was the first step in one of the early syntheses of steroids. The angular methyl group is introduced from the quinone, and the other functional groups were used for further structural elaboration. 

Diffusion control and pre-association in nitrosation, nitration, and halogenation, 16, 1 Dimethyl sulphoxide, physical organic chemistry of reactions, in, 14, 133 Diolefin crystals, photodimerization and photopolymerization of, 30, 117 Dipolar aptotic and protic solvents, rates of bimolecular substitution reactions in,... 

Catalytic nucleophilic substitution reactions comprise some of the most commonly used catalytic processes in S)mthetic organic chemistry. Substitutions at aromatic and vinylic halides and sulfonates, sho vn generically in Equation 19.1, are commonplace in the preparation of pharmaceutical candidates, have often been used in the s)mtheses of natural products, and have been used many times in the syntheses of sophisticated conjugated organic materials. These metal-catalyzed reactions are typically called cross-coupling reactions. ... 

Electrophilic Aromatic Substitution. Friedel-Crafts-type electrophihc aromatic substitution reactions constitute one of the most important classes of reactions in organic chemistry. Such reactions are traditionally promoted by stoichiometric amounts of Lewis acid, presenting purification and waste problems, particularly when carried out on an industrial scale. 

Section 8 1 Nucleophilic substitution is an important reaction type m synthetic organic chemistry because it is one of the mam methods for functional group transformations Examples of synthetically useful nucleophilic sub stitutions were given m Table 8 1 It is a good idea to return to that table and review its entries now that the details of nucleophilic substitution have been covered... 

We call this reaction electrophihc aromatic substitution, it is one of the fundamental processes of organic chemistry... 

In the first century of "organic" chemistry much attention was given to the structures of carbogens and their transformations. Reactions were classified according to the types of substrates that underwent the chemical change (for example "aromatic substitution," "carbonyl addition," "halide displacement," "ester condensation"). Chemistry was taught and learned as transformations characteristic of a structural class (e.g. phenol, aldehyde) or structural subunit... 

---