Carbon Dioxide → Phenylpropiolic Acid

Participants

Reaction Steps

The longer reaction time for the P1 catalysed reaction may be due to the heterogeneous reaction behavior in this solid catalyst system. A reaction intermediate Poly(NHC—CO2)0.5(NHC—Cu)0.5 was synthesized by reaction of Poly(NHC)0.5(NHC—Cu)0.5 (P1) with CO2. This intermediate was directly used to react with stoichiometric amount 1-ethynylbenzene (1 eq. to NHC—CO2) under standard condition without an additional CO2 source. 52% yield of phenylpropiolic acid was obtained in 24 hours. With these experiment results, it is believe that the unique structure of P1 catalyst is the key to the high activities. The free carbene species in the structure are randomly located around copper center and act as an organo catalyst to activate CO2. This essential step may reduce the activation energy barrier for CO2 insertion.

Provenance & Evidence