[shrikantvarma]

is there any need for lewis acid catalyst while doing grignard reaction of acyl halide & alkyl magnesium bromide ?? what is the ideal condition to get good yield??

[MissPhosgene]

My experience has been double additions when grignards are done with acyl chlorides, specifically ethyl oxalyl chloride. I kept the temperature below -60 during the addition of 1.0 M grignard to a 0.5 M solution of the acyl chloride. THF was the solvent. There was no addition product at the ester, only clean double addition at the acyl chloride. However, the same reaction done with an ethyl ester gave only the mono-addition product.

I would not add a Lewis acid because it can coordinate with the carbonyl and result in a second equivalent of grignard being added. Depending on what LA you pick, it could also screw up your grignard reagent.