Organic Chemistry Forum for Graduate Students and Professionals / Re: Kumada-coupling of thienothiophene with alkyl chain« Last post by opsomath on Today at 09:20:09 AM »
I agree that titration is worth doing any time you have a Grignard that requires any precision - that is, where the separation of products isn't trivial, or where the unconverted halide might cause a side reaction. I generally do Kumadas of thiophenes while cooling with an ice bath, too, although I've never tried a PEG coupling. You may also consider starting in THF to begin with. A lot of reactions simply don't work in ether that do work in THF. I have never seen a Ni Kumada that required reflux, so that is probably not helping.