Patent ID: 7329727

Claim:
A method of polymerizing aminoacid-N-carboxyanhydride monomer wherein the N-carboxyanhydride monomer comprises the following ring: said method comprising: (a) combining a first NCA monomer with an initiator molecule complex comprised of: (i) a low valent metal capable of undergoing an oxidative addition reaction wherein the oxidative addition reaction formally increases the oxidation state of the low valent metal by two electrons; and (ii) an electron donor comprising a Lewis base; (b) allowing the initiator molecule complex to: (i) open the ring of the first NCA through oxidative addition across either the O—C 5 or O—C 2 anhydride bond; (ii) combine with a second NCA monomer, to form a polyaminoacid chain containing a first amido containing metallacycle; and (c) allowing a third NCA monomer to combine with the first amido containing metallacycle so that: (i) the amido nitrogen of the first amido containing metallacycle attacks the carbonyl carbon of the NCA and the third NCA is added to the polyaminoacid chain; and (ii) a second amido containing metallacycle is generated.