Expanded Ring NHC Silver Carboxylate Complexes as Efficient and Reusable Catalysts for the Carboxylative Cyclization of Unsubstituted Propargylic Derivatives. Issue 11 (3rd May 2021)

• Record Type: Journal Article
• Authors: Cervantes‐Reyes, Alejandro; Saxl, Tobias; Stein, Philipp M.; Rudolph, Matthias; Rominger, Frank; Asiri, Abdullah M.; Hashmi, A. Stephen K.
• Is Part Of: ChemSusChem. Volume 14:Issue 11(2021)
• Page Start: 2367
• Page End: 2374
• Publication Date: 2021-05-03
• Subjects: carbon dioxide -- cyclic carbonates -- N-heterocyclic carbenes -- oxazolidinones -- silver; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202002822
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: Stabilized by a bulky N‐heterocyclic carbene [ BP DPr, 1, 3‐bis(2, 6‐diisopropylphenyl)‐1, 3‐diazonine‐2‐ylidene] ligand, new silver carboxylate complexes of the form BP DPrAgO2 C‐R (R=Me, Ph) have been synthesized and fully characterized in solution and in the solid state and implemented as sole catalysts (base‐, additive‐, and, in some cases, solvent‐free) in the challenging fixation of carbon dioxide to unsubstituted propargylic derivatives for the synthesis of oxazolidinones and α‐methylene cyclic carbonates. Derived from X‐ray diffraction studies, the molecular geometry and the concept of buried volume were employed to describe the structural and steric features of these silver complexes. Their stability and efficiency as catalysts have been demonstrated by the synthesis of 29 carboxylation products (72–98 % yield) at low catalyst loadings (0.01–1.5 mol%). Characteristics are high turnover numbers (up to 9400), catalyst recyclability (up to 96 % yield after the 7th cycle with no decomposition of the silver complex), and the possibility to scale‐up the reaction. Abstract : CO2 fixation : The first expanded ring N‐heterocyclic carbene silver carboxylate complexes are efficient and reusable catalysts in the chemical fixation of carbon dioxide to unsubstituted propargylic derivatives under homogeneous or heterogeneous reaction conditions.