A Highly Lewis Acidic Strontium ansa‐Arene Complex for Lewis Acid Catalysis and Isobutylene Polymerization. Issue 49 (28th September 2020)

• Record Type: Journal Article
• Authors: Dabringhaus, Philipp; Schorpp, Marcel; Scherer, Harald; Krossing, Ingo
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 49(2020)
• Page Start: 22023
• Page End: 22027
• Publication Date: 2020-09-28
• Subjects: alkaline earth metals -- CO2 reduction -- Lewis acids -- polymerization reactions -- strontium; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202010019
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The potential of a dicationic strontium ansa ‐arene complex for Lewis acid catalysis has been explored. The key to its synthesis was a simple salt metathesis from SrI2 and 2 Ag[Al(OR F )4 ], giving the base‐free strontium‐perfluoroalkoxyaluminate Sr[Al(OR F )4 ]2 (OR F =OC(CF3 )3 ). Addition of an ansa ‐arene yielded the highly Lewis acidic, dicationic strontium ansa ‐arene complex. In preliminary experiments, the complex was successfully applied as a catalyst in CO2 ‐reduction to CH4 and a surprisingly controlled isobutylene polymerization reaction. Abstract : The synthesis of a highly Lewis acidic, dicationic strontium ansa ‐arene complex is reported as the salt of a weakly coordinating [Al(OR F )4 ] − anion (OR F =C(CF3 )3 ). The base‐free strontium perfluoroalkoxyaluminate Sr [Al(OR F )4 ]2 complex is the source of a naked strontium dication. The strontium ansa ‐arene complex was successfully applied as catalyst in CO2 reduction and a highly controlled isobutylene polymerization.