Difference between Alkylation and Acylation
Difference between Alkylation and Acylation

Difference between Alkylation and Acylation

Acylation and alkylation are the two electrophilic exchange reactions in the organic chemistry. Alkylation is an exchange of group of alkyl starting with one molecule then onto the next utilizing alkylating agent. Acylation is the procedure of adding acyl group to compound utilizing acylating agent.

Alkylation

Alkylation is the exchange of alkyl group starting with one molecule then onto the next. The alkyl group might be exchanged as alkyl carbocation, a carbanion, a free radical or a carbine.

Acylation

Acylation is the procedure of accumulating an acyl group to compound. The compound giving the acyl group is known as the acylating agent.

Alkylation VS Acylation

Some contrasts related to above terms are given below

  • Definition:

Alkylation is the procedure of acquainting the hydrocarbon chain with the beginning material.

Acylation is the procedure of accumulating the acyl group with the beginning material utilizing an acylating agent.

  • General change:

In alkylation the general change is from R-H towards R-R’.

In acylation the general change is from R-H towards R-COR’.

  • Agents:

The case of alkylation agents is as follow:  Alkyl carbocations, carbanions, free radical and carbines.

The case of acylation agents is as follow: acyl halides and acyl anhydrides of carboxylic acids

  • Reagents:

In alkylation, normally alkyl halides (R-Cl) and lewis catalyst, for example, aluminum (AlCl3) can go about as reagents. On the other hand, organo-metal complexes (R-MgBr) can be utilized rather than alkyl halides. Also, ZnCl2, BF3, FeCl3 can be utilized rather than AlCl3.

 In acylation, normally acyl halides (R-COCl) and lewis catalyst go about as reagents. On the other hand, acid anhydrides that is (RCO)2O can be utilized rather than acyl halides.

  • Mechanism:

In alkylation of benzene, a hydrogen atom present in benzene ring is supplanted by methyl group.

In acylation of benzene, hydrogen atom present in benzene ring is supplanted by CH3CO-group.

  • Formation of cation:

In alkylation, the carbocation (R+) is shaped by the “expulsion” of halide by Lewis acid catalyst.

In acylation, the acylium ion or acyl cation (RCO+) is shaped by the “expulsion” of halide by Lewis acid catalyst.

  • Friedel-Craft Reactions

In alkylation, aryl or vinyl halides don’t experience alkylation response in light of the fact that their intermediary carbocation is usually unstable.

An acylation reaction dependably offers ketones, in light of the fact that HCOCl breaks down to CO and HCl under reaction situation.

  • Carbocation:

In alkylation, carbocation is inclined to revamp and frame an extremely stable carbocation, which will experience alkylation reaction.

In acylation, an acylium ion is balanced out by the reverberation structures. This additional stability avoids the adjustment of carbocation.

Conclusion

From above article we can conclude that alkylation is the procedure of acquainting the hydrocarbon chain with the beginning material while acylation is the procedure of accumulating the acyl group with the beginning material utilizing an acylating agent. The agents in alkylation are alkyl carbocations, carbanions, free radical and carbines while the acylation agents are acyl halides and acyl anhydrides of carboxylic acids. In alkylation of benzene, a hydrogen atom present in benzene ring is supplanted by methyl group while in acylation of benzene; it is supplanted by CH3CO-group. In alkylation, aryl or vinyl halides don’t experience alkylation while acylation reaction dependably offers ketones.