A New Class of Easily Activated Palladium Precatalysts for Facile C−N Cross-Coupling Reactions and the Low Temperature Oxidative Addition of Aryl Chlorides
作者:Mark R. Biscoe、Brett P. Fors、Stephen L. Buchwald
DOI:10.1021/ja801137k
日期:2008.5.1
one-component Pd precatalysts bearing biarylphosphine ligands is described. These precatalysts are air- and thermally stable, are easilyactivated under normal reaction conditions at or below room temperature, and ensure the formation of the highly active monoligated Pd(0) complex necessary for oxidative addition. The use of these precatalysts as a convenient source of LPd(0) in C-N cross-coupling reactions
MgCl 2 -catalyzed trifluoromethylation of carbonyl compounds using (trifluoromethyl)trimethylsilane as the trifluoromethylating agent
作者:Bin Cui、Hui Sun、Yibo Xu、Lili Duan、Yue-Ming Li
DOI:10.1016/j.tet.2017.10.021
日期:2017.11
Using (trifluoromethyl)trimethylsilane (TMSCF3) as the trifluoromethylating agent, MgCl2-catalyzed trifluoromethylation of carbonylcompounds proceeded readily at room temperature. In the presence of 10 mol% of MgCl2, a variety of carbonyl substrates such as aliphatic/aromatic aldehydes, acyclic/cyclic ketones and esters could be trifluoromethylated in DMF, giving the corresponding trimethylsilyl ethers
Lewis base-catalyzed perfluoroalkylation of carbonyl compounds and aldimines with (perfluoroalkyl)trimethylsilanes (TMSCF3, TMSC2F5, and TMSC3F7) is described. The nitrogen- or oxygen-containing an...
Scope and Mechanistic Insights into the Use of Tetradecyl(trihexyl)phosphonium Bistriflimide: A Remarkably Selective Ionic Liquid Solvent for Substitution Reactions
作者:James McNulty、Jerald J. Nair、Sreedhar Cheekoori、Vladimir Larichev、Alfredo Capretta、Al J. Robertson
DOI:10.1002/chem.200600653
日期:2006.12.13
A survey of substitutionreactions conducted in a phosphoniumbistriflimideionicliquid is presented. The results demonstrate high selectivity favoring substitution over typically competitive elimination and solvolytic processes even when challenging secondary and tertiary electrophiles are employed. The first reports of Kornblum substitutionreactions in an ionicliquid are described that proceed
Metal-free radical aromatic carbonylations mediated by weak bases
作者:Denis Koziakov、Axel Jacobi von Wangelin
DOI:10.1039/c7ob01572k
日期:——
We report a new method of metal-free alkoxycarbonylation. This reaction involves the generation of aryl radicals from arenediazonium salts by a very weak base (HCO2Na) under mild conditions. Subsequent radical trapping with carbon monoxide and alcohols gives alkyl benzoates. The conditions (metal-free, 1 equiv. base, MeCN, r.t., 3 h) tolerate various functional groups (I, Br, Cl, CF3, SF5, NO2, ester)