Regioselective C−H Xanthylation as a Platform for Polyolefin Functionalization

• Published in: Angewandte Chemie International Edition Vol. 57; no. 21; pp. 6261 - 6265
• Main Authors: Williamson, Jill B., Czaplyski, William L., Alexanian, Erik J., Leibfarth, Frank A.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 22.05.2018
• Edition: International ed. in English
• Subjects: amidyl radicals; Chain branching; Chain scission; Cleavage; C−H functionalization; Functional groups; photochemistry; polymer modification; Polymerization; Polymers; Polyolefins; Regioselectivity; Thermoplastic resins; C−H functionalization; polymer modification; polymers; amidyl radicals; photochemistry
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201803020

Polyolefins that contain polar functional groups are important materials for next‐generation lightweight engineering thermoplastics. Post‐polymerization modification is an ideal method for the incorporation of polar groups into branched polyolefins; however, it typically results in chain scission events, which have deleterious effects on polymer properties. Herein, we report a metal‐free method for radical‐mediated C−H xanthylation that results in the regioselective functionalization of branched polyolefins without coincident polymer‐chain scission. This method enables a tunable degree of polymer functionalization and capitalizes on the versatility of the xanthate functional group to unlock a wide variety of C−H transformations previously inaccessible on branched polyolefins. Commodity polymers see the light: Functionalized polyolefins were obtained by intermolecular, metal‐free, and regioselective xanthylation without the chain‐scission side reactions that plague current commercial strategies. The method enables a tunable degree of polymer functionalization and capitalizes on the versatility of the xanthate functional group to unlock a wide variety of C−H transformations previously inaccessible on branched polyolefins.