Mechanistic elucidation of monoalkyltin(iv)-catalyzed esterification. Issue 10 (19th February 2021)

• Record Type: Journal Article
• Authors: Wolzak, Lukas A.; Hermans, Joen J.; de Vries, Folkert; van den Berg, Keimpe J.; Reek, Joost N. H.; Tromp, Moniek; Korstanje, Ties J.
• Is Part Of: Catalysis science & technology. Volume 11:Issue 10(2021)
• Page Start: 3326
• Page End: 3332
• Publication Date: 2021-02-19
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/d1cy00184a
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : Monoalkyltin-catalyzed esterification was studied under industrially relevant catalytic conditions and was found to have a monomeric active species, with both a monomeric and a dimeric resting state. Abstract : Monoalkyltin(iv ) complexes are well-known catalysts for esterification reactions and polyester formation, yet the mode of operation of these Lewis acidic complexes is still unknown. Here, we report on mechanistic studies of n -butylstannoic acid in stoichiometric and catalytic reactions, analyzed by NMR, IR and MS techniques. While the chemistry of n -butyltin(iv ) carboxylates is dominated by formation of multinuclear tin assemblies, we found that under catalytically relevant conditions only monomeric n -BuSn(OAc)3 and dimeric ( n -BuSnOAc2 OEt)2 are present. Density functional theory (DFT) calculations provide support for a mononuclear mechanism, where n -BuSn(OAc)3 and dimeric ( n -BuSnOAc2 OEt)2 are regarded as off-cycle species, and suggest that carbon–oxygen bond breaking is the rate-determining step.