Sn(OTf)2 and Sc(OTf)3: Efficient and versatile catalysts for the controlled polymerization of lactones

✍ Scribed by M. Möller; R. Kånge; J. L. Hedrick

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 137 KB
• Volume: 38
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(20000601)38:11<2067::aid-pola150>3.0.co;2-1

✦ Synopsis

A general and novel method for the controlled synthesis of aliphatic polyesters is presented. The evaluation of stannous (II) trifluoromethane sulfonate [Sn(OTf) 2 ] and scandium (III) trifluoromethane sulfonate [Sc(OTf) 3 ] as catalysts for the ring-opening polymerization (ROP) of various lactones is described as a route to polyesters under mild and highly selective polymerization conditions. Size exclusion chromatograms of poly(⑀-caprolactone) initiated from ethanol in the presence of either Sn(OTf) 2 or Sc(OTf) 3 demonstrate the facile synthesis of narrowly dispersed products. Predictable molecular weights, typical of a living or controlled polymerization, were obtained with high yields. These catalysts are versatile and applicable toward the ROP of other cyclic (di)esters, including ␤-butyrolactone, which produces the synthetic analogue of the biopolymer poly(␤-hydroxybutyrate).