Grignard reaction

[reising1]

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Why is a Grignard reaction nucleophilic substitution?

I thought it would be nucleophilic addition, because the nucleophile (the R group on the RMgX) is attacking the electrophile (the carbonyl carbon) and adding an R group to the carbonyl.

 

[deh2ase]

A grignard can act as both depending on the substrate. For example if you react it with an acyl chloride (RCOCl) you would generate a ketone by displacing the Cl, substitution. If you react it with an aldehyde (RCHO), you would make an alcohol, notice no leaving group was displaced, addition.

 

[reising1]

A grignard can act as both depending on the substrate. For example if you react it with an acyl chloride (RCOCl) you would generate a ketone by displacing the Cl, substitution. If you react it with an aldehyde (RCHO), you would make an alcohol, notice no leaving group was displaced, addition.

That makes sense! Thanks!

Would you say it normally acts via substitution or addition?

 

[deh2ase]

It would be hard to generalize something like this. There are many reactions where a grignard is used for addition and equally there are many reactions where it is used for substitution. I think it is more important to recognize what it is being used as based on the starting material and product.

 

[reising1]

It would be hard to generalize something like this. There are many reactions where a grignard is used for addition and equally there are many reactions where it is used for substitution. I think it is more important to recognize what it is being used as based on the starting material and product.

Fair enough, thanks.