New chiral phospholanes; Synthesis, characterization, and use in asymmetric hydrogenation reactions
作者:Mark J. Burk、John E. Feaster、Richard L. Harlow
DOI:10.1016/s0957-4166(00)86109-1
日期:1991.1
5-disubstituted-1-phenylphospholanes which are then employed in the preparation of a new series of C2-symmetric bis- and C3-symmetric tris(phospholane) ligands. A versatile three-step route to the important chiral 1,4-diol intermediates, used in the phosphinesyntheses, is outlined. Rhodiumcomplexes bearing the newphosphineligands were prepared and shown to act as efficient catalyst precursors for the enantioselective
enantioselectivities in methanol as the solvent. This may account for optimised steric and electroniceffects. However, by changing the solvent catalysts with other backbones can give rise to excellent results. This gives proof that simple correlations between steric and electronic properties and results in the enantioselective hydrogenation frequently claimed in literature are not general.
Pseudo-C2-symmetric chiral phosphorus ylide is designed and synthesized for the enantioselective preparation of allenic esters, amides, ketone, and nitrile. Up to 92% ee is achieved.
设计并合成了伪C 2对称的手性磷叶立德,用于对映体制备烯丙酸酯,酰胺,酮和腈。达到了92%ee。
Synthesis of a New Chiral Bisphospholane Ligand for the Rh(I)-Catalyzed Enantioselective Hydrogenation of Isomeric β-Acylamido Acrylates
作者:Jens Holz、Axel Monsees、Haijun Jiao、Jinsong You、Igor V. Komarov、Christine Fischer、Karlheinz Drauz、Armin Börner
DOI:10.1021/jo020453h
日期:2003.3.1
The highly stereoselective synthesis of a chiral silylphospholane has been described, which can be advantageously used as a building block under base-free conditions for the construction of diphosphines related to DuPHOS. The utility of silylphospholane is shown in the synthesis of a new bisphospholane ligand 1 (MalPHOS), which is characterized by a maleic anhydride backbone. The ligand forms with
The invention relates to novel phosphorus compounds, to a method for producing said phosphorus compounds and their intermediate products. The invention also relates to the catalysts produced according to the invention on the basis of the phosphorus compounds and to their use in catalytic processes, especially in asymmetric catalytic processes.