Bismuth tris-silylamide: A new non-toxic metal catalyst for the ring opening (co-)polymerization of cyclic esters under smooth conditions

ROP of rac-LA and ε-CL as well as their copolymerization was achieved by means of bismuth tris-silylamide Bi[N(SiMe3)2]3 in solution. Upon activation with a borane molecule, the bismuth initiator produces polymers having narrower polymer distributions.