Question

(i) Using curved-arrow notation, show the formation of reactive intermediates when the following covalent bonds undergo heterolytic cleavage.

(a) CH₃–SCH₃,

(b) CH₃–CN,

(c) CH₃–Cu

(ii) Giving justification, categories the following molecules/ions as nucleophile or electrophile:

HS^– , BF₃, C₂H₅O^– , (CH₃₎₃N;

\(C\overset{+}{l}\), \(CH_3-\overset{+}{C}-H_2N-:\),\(\overset{+}{N}O_2\)

Answer 1

(i)

(a) 

(b) 

(c) 

(ii) Nucleophiles: HS^– ,C₂H₅O^– , (CH₃)₃N:, HN. 

These species have unshared pair of electrons, which can be donated and shared with an electrophile.

Electrophiles: BF₃,Cl⁺ ,  \(CH_3-\overset{+}{C}=O\) , \(\overset{+}{N}O_2\)

reactive sites have only six valence electrons; can accept electron pair from a nucleophile.