Abstract:Supported CBS catalysts with controlled molecular weight and low polydispersity were successfully synthesized by reversible addition-fragmentation chain transfer(RAFT) polymerization, using cumyl dithiobenzoate(CDB) as RAFT agent, AIBN as initiator, styrene(St) and self-made functional styrene(FSt) as monomer. The CBS catalysts was used in the asymmetric reduction of acetophenone, and characterized by GPC and FT-IR. The influence of the FSt concentration on the molecular weight and the molecular weight distribution on the catalyst precursor was investigated. The difference between the catalysts by RAFT polymerization and the traditional free radical polymerization was studied. The interaction between the CBS catalytic unit and the active end groups of the dithioester was also investigated. The results show that, as increase of FSt content, the molecular weight of the polymer decreases, and the distribution of PDI becomes larger after about 1.25, the active end group of dithioate does not affect the activity of the catalyst. The ee value of phenylethyl alcohol firstly increases to 94% with the FSt concentration and the yield is up to 97.2%.