78406-16-3Relevant academic research and scientific papers
Highly diastereoselective Csp3 -Csp 2 Negishi cross-coupling with 1,2-, 1,3- and 1,4-substituted cycloalkylzinc compounds
Thaler, Tobias,Haag, Benjamin,Gavryushin, Andrei,Schober, Katrin,Hartmann, Evelyn,Gschwind, Ruth M.,Zipse, Hendrik,Mayer, Peter,Knochel, Paul
experimental part, p. 125 - 130 (2010/07/18)
Stereoselective functionalizations of organic molecules are of great importance to modern synthesis. A stereoselective preparation of pharmaceutically active molecules is often required to ensure the appropriate biological activity. Thereby, diastereoselective methods represent valuable tools for an efficient set-up of multiple stereocentres. In this article, highly diastereoselective Csp3 Negishi cross-couplings of various cycloalkylzinc reagents with aryl halides are reported. In all cases, the thermodynamically most-stable stereoisomer was obtained. Remarkably, this diastereoselective coupling was successful not only for 1,2-substituted cyclic systems, but also for 1,3- and 1,4-substituted cyclohexylzinc reagents. The origin of this remote stereocontrol was investigated by NMR experiments and density functional theory calculations. A detailed mechanism based on these experimental and theoretical data is proposed.
Stille cross-couplings of unactivated secondary alkyl halides using monoorganotin reagents
Powell, David A.,Maki, Toshihide,Fu, Gregory C.
, p. 510 - 511 (2007/10/03)
The first catalyst that achieves Stille cross-couplings of secondary (as well as primary) alkyl halides has been developed. The method employs easily handled and inexpensive catalyst components (NiCl2 and 2,2′-bipyridine) and, through the use of monoorganotin reagents, avoids the formation of toxic and difficult-to-remove triorganotin side products. Copyright
Montmorillonite clay catalysis. Part 8. Synthesis of arylcholestenes by Friedel-Crafts reaction catalysed by montmorillonite K-10
Li, Li-Jun,Lu, Bo,Li, Tong-Shuang,Li, Ji-Tai
, p. 1439 - 1449 (2007/10/03)
A series of 3β-arylcholestenes were synthesised by Friedel-Crafts reaction of cholesterol with arenes catalysed by montmorillonite K-10.
