Complexes of trimethylsilyl trifluoromethanesulfonate with nitrogen, oxygen, and phosphorus donors
| Autor: | Neil Burford, Seth Chhina, Brian O. Patrick, Hilary A. Jenkins, Alasdair P. M. Robertson, J S Hector Cortes, Saurabh S. Chitnis |
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| Rok vydání: | 2016 |
| Předmět: |
chemistry.chemical_classification
010405 organic chemistry Stereochemistry Ligand Organic Chemistry Ionic bonding General Chemistry Nuclear magnetic resonance spectroscopy 010402 general chemistry 01 natural sciences Acceptor Medicinal chemistry Catalysis 0104 chemical sciences Coordination complex chemistry.chemical_compound chemistry Trimethylsilyl trifluoromethanesulfonate Lewis acids and bases Single crystal |
| Zdroj: | Canadian Journal of Chemistry. 94:424-429 |
| ISSN: | 1480-3291 0008-4042 |
| DOI: | 10.1139/cjc-2015-0435 |
| Popis: | The Lewis acceptor chemistry of Me3SiOTf with p-block Lewis bases has been explored and a library of complexes has been characterized by spectroscopic and, where possible, crystallographic methods. Compounds with the generic formula [Me3Si(L)][OTf] (L = 4-dmap, pyr, imz, OPMe3, OPCy3, OPPh3, OpyrMe, dmso, PMe3) were isolated from 1:1 mixtures of Me3SiOTf and the respective ligand in CH2Cl2. Characterization by NMR spectroscopy confirmed the solution stability of all but [Me3Si(PMe3)][OTf], with indications that the latter dissociates into PMe3 and Me3SiOTf. Solid-state structures of [Me3Si(4-dmap)][OTf], [Me3Si(pyr)][OTf], [Me3Si(OPCy3)][OTf], [Me3Si(OPPh3)][OTf], [Me3Si(OpyrMe)][OTf], and [Me3Si(PMe3)][OTf] were elucidated by single crystal X-ray diffraction, confirming the envisaged ionic formulations resulting from the displacement of the OTf anion from the silicon center of Me3SiOTf by the incoming ligand. Mixtures of Me3SiOTf with other related donors, including ChPPh3 (Ch = S or Se), NEt3, SMe2, PPh3, 2,2′-bipy, or Me2CO, show no evidence of reaction under ambient conditions, reflecting the lower basicity and (or) greater steric encumbrance of these ligands. Reactions of Me3SiOTf with bis-donor ligands yielded complexes of the generic formulae [Me3Si(L–L)SiMe3][OTf]2 (L–L = 4,4′-bipy, tmeda, dmpe) and [Me3Si(L–L)][OTf] (L–L = 4,4′-bipy, tmeda, dmpe). The tmeda and dmpe complexes, however, were found to dissociate in solution, with complexes only prevailing in the solid phase. X-ray diffraction studies of [Me3Si(4,4′-bipy)SiMe3][OTf]2 and [Me3Si(dmpe)SiMe3][OTf]2 confirmed the expected connectivities and ionic formulations, with Si–ligand bond lengths comparable to those observed in [Me3Si(pyr)][OTf] and [Me3Si(PMe3)][OTf], respectively. |
| Databáze: | OpenAIRE |
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