Learning Objective: To study lone pair's role in chemical reactions as electron donors.
Prerequisites:
Chapter: Fundamentals of Organic Reactions
Sub-topic: Lone Pair
Author's Note: Since lone pairs kept away from bond-forming reactions and remained nonbonded, still they are considered rich in electron density. They tend to donate the electron richness to deficient counterparts and, therefore, take part in chemical reactions. However, there is a catch. Not all atoms having a lone pair are reactive, and understanding when and how they react is very important to organic chemistry.
Chemical property of the Lone pair - Nucleophiles, Lewis Bases, Lowry Bronsted Bases
Lone pairs containing atoms are rich in electrons and can act as electron donors. Such donor groups of atoms are called Lewis bases or nucleophiles.

There are three possibilities-
If a lone pair donates to an electrophile like ...
If the lone pair donates to an electrophilic centre ....
If the lone pair donates to a proton .....
However, not all lone pair containing atoms are electron donors....
