FRSR · Substitution92 slides

Free Radical Substitution Reactions

Curriculum Module FRSR

Free Radical Substitution Reactions

Halogenation of Alkanes, Allylic/Benzylic Bromination (NBS) & Reactivity vs Selectivity

92 SlidesFull Master Compendium

Core Mechanistic Pathways

Chlorination vs Bromination selectivity ratios (1:3.8:5 for Cl vs 1:82:1600 for Br)
Hammond’s Postulate applied to early vs late transition states
Allylic and benzylic bromination with N-Bromosuccinimide (NBS)
Sulfuryl chloride (SO₂Cl₂) free radical chlorination
Inhibition by oxygen and radical scavengers (TEMPO, hydroquinone)
Stereochemical racemization at chiral halogenation carbons

Key Reagents & Conditions

Cl₂ / hvBr₂ / hv at elevated temperatureNBS / hν in CCl₄SO₂Cl₂ / light

Stereochemical Dynamics

Shallow pyramidal inversion of radical intermediates resulting in complete loss of stereochemical configuration.

Module Summary & Study Guidance

Master guide to alkane halogenations and selective functionalization. Full quantitative treatment of relative reaction rates, statistical versus energetic yield predictions, and NBS mechanistic cycles.

Exam Orientation: JEE Main & Advanced · Reactivity-selectivity principle. All materials are embedded directly on Chem-Mantra with online presentation and secure reference reading modes.

Curriculum Module FRSR

Free Radical Substitution Reactions

Halogenation of Alkanes, Allylic/Benzylic Bromination (NBS) & Reactivity vs Selectivity

92 SlidesFull Master Compendium

Core Mechanistic Pathways

Chlorination vs Bromination selectivity ratios (1:3.8:5 for Cl vs 1:82:1600 for Br)
Hammond’s Postulate applied to early vs late transition states
Allylic and benzylic bromination with N-Bromosuccinimide (NBS)
Sulfuryl chloride (SO₂Cl₂) free radical chlorination
Inhibition by oxygen and radical scavengers (TEMPO, hydroquinone)
Stereochemical racemization at chiral halogenation carbons

Key Reagents & Conditions

Cl₂ / hvBr₂ / hv at elevated temperatureNBS / hν in CCl₄SO₂Cl₂ / light

Stereochemical Dynamics

Shallow pyramidal inversion of radical intermediates resulting in complete loss of stereochemical configuration.

Module Summary & Study Guidance

Exam Orientation: JEE Main & Advanced · Reactivity-selectivity principle. All materials are embedded directly on Chem-Mantra with online presentation and secure reference reading modes.