Chemical reactions are rearrangements of atoms as the bonds between them are broken and new ones are formed. For example, in the following reaction, the C-Br bond is broken, and the C-Cl bond is formed: Let’s now compare … Read more
Importance of radical Halogenation The source of the large majority of organic materials used for a countless number of applications, which can be plastics, drugs, paints, clothes, electronics and many more is the crude oil. We need to … Read more
In allylic bromination, the Br atom appears on the carbon next to the double bond: This reaction goes through a radical mechanism, and it is interesting to notice the difference with the aniti-Markovnikov radical bromination: We … Read more
In this post, we will talk about the stereochemistry of radical halogenation leading to racemic mixture of enantiomers or diastereomers. Before getting into more details, let’s recall that radicals are similar to carbocations as both are trigonal planar, sp2-hybrydized atoms … Read more
Check Also: Free-Radical Addition of HBr: Anti-Markovnikov Addition Initiation Propagation Termination in Radical Reactions Selectivity in Radical Halogenation Stability of Radicals Resonance Structures of Radicals Stereochemistry of Radical Halogenation Allylic Bromination Radical Halogenation in Organic Synthesis
Radicals are reactive species with a single unpaired electron. They are formed by homolytic cleavage of a covalent bond, meaning that each atom gets one electron of the covalent bond upon its breaking. An example is the hemolysis of halogens, … Read more
In the previous post, when discussing the mechanism of radical halogenation, we saw that polyhalogenation is a common issue as it results in a mixture of haloalkanes. Monohalogenation, on the other hand, is more useful for preparing haloalkanes used in … Read more
Initiation, Propagation, Termination – The Mechanisms Let’s discuss the chlorination of ethane to illustrate the three important steps of radical halogenation: Initiation of Radical Halogenation The reaction starts with homolysis of a σ bond forming two radicals. This is … Read more
We learned earlier that according to Markovnikov’s rule, the addition of an HX acid to an alkene produces the more substituted alkyl halide as the major product: Interestingly, in the presence of peroxides, HBr forms the less substituted … Read more
