Ansmann N, Hartmann D, Sailer S, Erdmann P, Maskey R, Schorpp M, Greb L. Synthesis and Characterization of Hypercoordinated Silicon Anions: Catching Intermediates of Lewis Base Catalysis.
Angew Chem Int Ed Engl 2022;
61:e202203947. [PMID:
35438836 PMCID:
PMC9325378 DOI:
10.1002/anie.202203947]
[Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Indexed: 11/24/2022]
Abstract
Anionic hypercoordinated silicates with weak donors were proposed as key intermediates in numerous silicon‐based reactions. However, their short‐lived nature rendered even spectroscopic observations highly challenging. Here, we characterize hypercoordinated silicon anions, including the first bromido‐, iodido‐, formato‐, acetato‐, triflato‐ and sulfato‐silicates. This is enabled by a new, donor‐free polymeric form of Lewis superacidic bis(perchlorocatecholato)silane 1. Spectroscopic, structural, and computational insights allow a reassessment of Gutmann's empirical rules for the role of silicon hypercoordination in synthesis and catalysis. The electronic perturbations of 1 exerted on the bound anions indicate pronounced substrate activation.
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