Organic Chemistry – Some Basic Principles and Techniques · Question 36

Total number of nucleophiles from the following is : NH3, PhSH, (H3C)2S, H2C=CH2, OH, H3O , (CH3)2 CO, [figure]

1. 4
2. 6
3. 5
4. 7

Answer

(3) 5

Solution

As per NCERT, a nucleophile is an electron-pair donor that attacks an electron-deficient centre; an electrophile is electron-seeking.

NH3: lone pair on N nucleophile

PhSH: lone pairs on S nucleophile

(H3C)2S: lone pairs on S nucleophile

H2C=CH2: loosely held π electrons; it attacks electrophiles (electrophilic addition) nucleophile

OH: negatively charged nucleophile

H3O : proton donor, electron deficient electrophile

(CH3)2CO and the imine >C=NCH3: the polar C=O / C=N bond makes the carbon electron deficient; these compounds typically undergo nucleophilic addition, i.e. they act as electrophiles (substrates attacked by nucleophiles).

Nucleophiles: NH3, PhSH, (H3C)2S, H2C=CH2, OH = 5

Answer: (3)