Metallic catalysts for chemo-, regio-and stereoselective reactions, and corresponding precursors
申请人:Sannicolo Francesco
公开号:US20050107248A1
公开(公告)日:2005-05-19
Metallic catalysts of the general formula (I) and their precursors, suitable for chemo- regio- and stereoselective reactions, derived from ortho-bis-(1-phospholanyl)-heteroarenes. The new catalysts are characterized by the presence of two homomorphic phospholanic rings set in adjacent positions of an aromatic pentatomic heterocycle.
Chiral ligands of the formula I or II,
may be obtained in high enantiomeric purity from compounds of the formulae III or IV, respectively,
with suitable phosphines, where the symbols R1, R, n, R3, R4, R' are as described in claim 1. The products may be converted into transition metal complexes which are useful as catalysts for asymmetric hydrogenation reactions.
The invention comprises a process for the preparation and isolation of a non-amorphous cationic rhodium complex having the formula: [Rh(ligand)
m
(diolefin)]
+
X
−
, wherein the ligand is an enantiomerically enriched organic compound possessing one or two ligating phosphorus atoms.
The invention relates to a process for the manufacture of ligands capable of forming metal complexes and such complexes; novel ligands with new backbones, complexes thereof with transition metals, the use of complexes of said ligands with transition metals as catalysts, as well as novel intermediates for the manufacture of said ligands. The ligand complexes are useful in stereoselective synthesis, especially hydrogenation, of various organic molecules. Especially, the process according to the invention is directed to the synthesis of compounds of the formulae IA and IIA, wherein the substituents have the meanings given in the description, and to novel compounds of these formulae as ligands.
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