98965-20-9Relevant academic research and scientific papers
Asymmetric Catalyses, 23. Optically Active Aminophosphanes - Synthesis and Use in the Rh-Catalyzed Enantioselective Hydrosilylation
Brunner, Henri,Weber, Hannelore
, p. 3380 - 3395 (2007/10/02)
New optically active P,N-ligands 6-15 were prepared by reaction of pyrrolimines, -amines, and pyridamines 1-5 with chlorophosphanes.With NEt3 as HCl scavenger the amine nitrogen NH groups were phosphinated selectively. n-BuLi as a base yielded a product mixture containing pyrrole nitrogen-phosphinated and doubly phosphinated compounds which could be separated by chromatography.On reaction with 2, the new P,N-ligands formed stable chelate complexes.In situ-catalysts from the optically active ligands 6-15 and 2 as well as the isolated Rh complexes 16-19 were used in the enantioselective hydrosilylation of acetophenone with diphenylsilane.Conversion and optical induction (up to 19.6percentee) in the formation of (+)- and (-)-phenylethanol depended on the Rh : ligand ratio, the Rh : substrate ratio, the reaction temperature, and the solvent.
