Synthesis of Silaoxazolinium Salts Bearing Weakly Coordinating Anions: Structures and Catalytic Activities in the Aldol Reaction
| Autor: | Anugu Chandra Sheker Reddy, Tohru Hatanaka, Zhang Chen, Yasuo Hatanaka, Tatsuya Minami |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
chemistry.chemical_classification
Trimethylsilyl Silicon Chemical shift Organic Chemistry Inorganic chemistry Salt (chemistry) chemistry.chemical_element Medicinal chemistry Catalysis Inorganic Chemistry NMR spectra database chemistry.chemical_compound chemistry Aldol reaction Physical and Theoretical Chemistry Chlorosilane |
| Zdroj: | Organometallics. 32:3575-3582 |
| ISSN: | 1520-6041 0276-7333 |
| DOI: | 10.1021/om400017f |
| Popis: | The synthesis and structures of silaoxazolinium salts 2 and their application to the catalytic Mukaiyama aldol reaction are described. The reaction of (N-amidomethyl)dimethylchlorosilane (1a) or (N-amidomethyl)bis(trimethylsilyl)chlorosilane (1b) with metal salts of weakly coordinating anions such as Na[TFPB] (TFPB = B[3,5-(CF3)2C6H3]4–) and Cs[CB11H12] (CB11H12– = carba-closo-dodecaborate) gave the corresponding five-membered-ring silaoxazolinium salts 2 in high yields (93–97%). The structures of a series of silaoxazolinium salts 2 were determined by X-ray crystal analysis as well as 29Si NMR spectra. It was proved that the silicon atoms of silaoxazolinium salts 2a,b are nearly completely free from the coordination of anions, and the geometries of the silicon centers are distorted tetrahedra. The 29Si chemical shifts of salts 2 appeared in the range +31 to +49 ppm, revealing the appreciable silylium cation character of the silicon. The silaoxazolinium salt of TFPB anion 2a exhibited effective catalytic a... |
| Databáze: | OpenAIRE |
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