Highly Tactic Cyclic Polynorbornene: Stereoselective Ring Expansion Metathesis Polymerization of Norbornene Catalyzed by a New Tethered Tungsten-Alkylidene Catalyst

• DOI: 10.1021/jacs.6b00014
• Publication Date: 2016-04-04T15:23:26Z
• Authors: Stella A. Gonsales; Tomohiro Kubo; Madison K. Flint; Khalil A. Abboud; Brent S. Sumerlin; Adam S. Veige
• Keywords: 540; 01 natural sciences; 0104 chemical sciences

The tungsten alkylidyne [(t)BuOCO]W≡C((t)Bu) (THF)2 (1) reacts with CO2, leading to complete cleavage of one C═O bond, followed by migratory insertion to generate the tungsten-oxo alkylidene 2. Complex 2 is the first catalyst to polymerize norbornene via ring expansion metathesis polymerization to yield highly cis-syndiotactic cyclic polynorbornene.