Development of pinene-derived N,P ligands and their utility in catalytic asymmetric hydrogenation
J Johan Verendel1, Pher G Andersson
1Department of Biochemistry and Organic Chemistry, Uppsala University, Box 576, BMC. S-751 23, Uppsala, Sweden.
Abstract:
New diastereomeric N,P-ligands, derived from the natural product (+)-alpha-pinene, have been synthesized and evaluated in iridium-catalyzed asymmetric hydrogenation. The ligands are tetrahydroquinoline derivatives synthesized directly from commercially available alpha-pinene utilizing resolution or recrystallization to separate diastereomers. In reduction of a range of different trisubstituted alkenes the catalysts express very different activities ranging from no activity to high activity. One of the catalysts gives good ee values for some substrates.
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