hey, Im doing this reaction in refluxing acetic acid and it works perfectly, high purity, high yield. However, since Im trying to make axially chiral compound, I was thinking using a chiral acid catalyst for the cyclization. Did that in refluxing toluene with 10-camphorsulfonic acid but the reaction is mess, it shows maybe 5 different products. Any idea what might be the cause? Is sulfonic acid too strong acid so it protonates my amine which leads to some side reaction? I did the reaction with BF3.OEt which seems to be stronger acid but that works well.
My boss suggested using weaker acid which im gonna do this week but looking for more opinions of experienced chemists.