1807-55-2Relevant articles and documents
Friedlaender
, p. 973,989 (1902)
Synthesis, Structure, and Properties of Amino-Substituted Benzhydrylium Ions – A Link between Ordinary Carbocations and Neutral Electrophiles
Mayer, Robert J.,Hampel, Nathalie,Mayer, Peter,Ofial, Armin R.,Mayr, Herbert
supporting information, p. 412 - 421 (2018/09/14)
Optimized synthetic procedures for the straightforward access to eleven amino-substituted diarylmethylium tetrafluoroborates are described. These benzhydrylium ions cover a range of seven orders of magnitude in electrophilicity and provide a link between ordinary carbocations and neutral electrophiles. Five of these highly stabilized benzhydrylium tetrafluoroborates were characterized by single-crystal X-ray crystallography. While the experimentally determined bond lengths and angles in the solid state perfectly agree with those calculated by DFT methods for the gas phase and aqueous solution, crystal packing accounts for large differences in the twist angles of the aryl groups found in the solid state as compared to calculated structures.
SILICA-BASED ZINC CATALYSTS. THEIR PREPARATION AND USE IN THE ALKOXYCARBONYLATION OF AMINES
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Page/Page column 22-28, (2018/12/13)
The present invention relates to silica-based heterogeneous zinc compounds which are suitable as catalysts in the reaction of amines with dialkyl carbonates to produce carbamates. The catalysts have the formula [SiO2]-CH2-CHR-X-COOZn[Y], wherein [SiO2] represents a silica carrier selected from the group consisting of ordered mesoporous silica and irregular amorphous narrow pore silica, R represents a moiety selected from the group consisting of hydrogen, -CH3, and -CH2CH3, preferably hydrogen, X is an aliphatic chain of 2 to 11 carbon atoms that optionally comprises ether moieties and [Y] represents a mono anion. The invention is also directed towards a method for the preparation of the aforementioned compounds and towards method for the alkoxycarbonylation of amines.