Advices For Studying Organic Chemistry

5. Nucleophile: “nucleus-loving” reagent

−

Carbanion

C +

Le

HA

wis acid

G+ G− C H + A−

−

Carbanion

C +

Lewis acid

G+CLG− C C + L−

3.4 THE USE OF CURVED ARROWS IN ILLUSTRATING REACTIONS

3.4A A Mechanism for the Reaction

Reaction:

H 2 OH+ HCl 3 O+ + Cl−

Mechanism:

H O + O+

H

H Cl H +

H

H Cl−

A water molecule uses one of the electron pairs

to form a bond to a proton of HCl. The bond

between the hydrogen and chlorine breaks with

the electron pair going to the chlorine atom

This leads to the

formation of a

hydronium ion and

a chloride ion.

G+ G−

Curved arrows point from electrons to the atom receiving the electrons.

1. Curved arrow:
   
   
   1. The curved arrow begins with a covalent bond or unshared electron pair (a site
      of higher electron density) and points toward a site of electron deficiency.