Dear All,
Recently I'm trying to synthesis attached compound with suzuki coupling by modified method reported from Angew.Chem. Int.Ed. 2017, 56,7097 –7101.
I got the right compound c by using reported protocl, but I got the wrong product when I tried to synthesis compund e with same protocl.
I attached the NMR of the wrong prodcut and the phenylboronic acid I made.
The isolated yield of this wrong product is around 50% as Triiodomesitylene as limited agent.
If anyone can point out a possible solutions or give me any advice would help me a lot.
Thanks
1H-Integral is to low for the CH3-Signals (in sum 9H at 2ppm) from mesitylene. Hydrolysis of the cyano group could be possible.
See:
https://vdocuments.mx/investigations-into-the-suzukimiyaura-coupling-aiming-at-multikilogram-synthesis.html
You should try with pinacol boronic ester
what you attached wrong product 1H-NMR and 13C-NMR was clearly shows deboronate of your starting material d with diglyme and unreacted Iodo starting material b.
Suzuki coupling not happened in this case I guess. I guess you have to optimize this reaction. I guess attached 1H-NMR and 13C-NMR was not pure single compound?
If you are getting protodeboronation you need to make the trifluoroborate or MIDA boronate instead and then do Suzuki. This is easy if you already have the commercial boronic acid ready to go.