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C C Tzschucke

Publications and source records attributed to C C Tzschucke.

2 recordsLinked to original sources

Application of non-covalently solid-phase bound catalysts.

Supported catalysts have become valuable tools for simplified product isolation and catalyst recycling. The common method is covalent attachment to a solid support. An alternative strategy is to immobilize catalysts by non-covalent bonding through hydrogen bridges, ionic, hydrophobic or fluorous interactions. Compared to covalent attachment, such non-covalent approaches increase the flexibility in the choice of the support-material, reaction conditions and work-up strategies. Numerous catalytic reactions employing one of these non-covalent fixation strategies have meanwhile appeared in the literature.

Adsorption↗

Chelated aryllithium reagents: ring size and chelating group effects.

[figure: see text] Chelation and aggregation in phenyllithium reagents with potential 5-, 6-, and 7-ring chelating ether and amine ortho substituents have been examined utilizing variable-temperature 6Li and 13C NMR spectroscopy, 6Li and 15N isotope labeling, and the effects of solvent additives. Both ether and amine form strong 5-ring chelates; 6-ring ether chelates compete well with THF, but 6-ring amine chelates barely do, and 7-ring amine chelates do not. o-Methoxymethylphenyllithium (4) forms an open dimer (9) and a pentacoordinate monomer with PMDTA (10).

Journal Article↗