Synthesis of the Spirocyclic Cyclohexadienone Ring System of the Schiarisanrins
摘要:
[GRAPHICS]Studies on the synthesis of the spirocyclic cyclohexadienone ring system 2 of the schiarisanrin family of natural products 1 are described and were based on the Lewis acid-promoted C-alkylation of the corresponding phenolic precursor.
Synthesis of the Spirocyclic Cyclohexadienone Ring System of the Schiarisanrins
摘要:
[GRAPHICS]Studies on the synthesis of the spirocyclic cyclohexadienone ring system 2 of the schiarisanrin family of natural products 1 are described and were based on the Lewis acid-promoted C-alkylation of the corresponding phenolic precursor.
Process For The Preparation Of Enantiomerically Enriched Beta Amino Acid Derivatives
申请人:Xiao Yi
公开号:US20080058522A1
公开(公告)日:2008-03-06
The present invention relates to a process for the efficient preparation of enantiomerically enriched beta amino acid derivatives wherein the amino group is unprotected. The product chiral beta amino acid derivatives are useful in the asymmetric synthesis of biologically active molecules. The process comprises an enantioselective hydrogenation of an amine-unprotected prochiral beta-amino acrylic acid or derivative thereof in the presence of a rhodium metal precursor complexed with a chiral mono- or bisphosphine ligand.
The present invention provides a process for the preparation of substituted piperidines which comprises an asymmetric hydrogenation of vinyl fluoride in the presence of a metal precursor complexed with a chiral mono- or biphosphine ligand.
Cycloolefin Phosphine Ligands and Their Use in Catalysis
申请人:Kadyrov Renat
公开号:US20080306264A1
公开(公告)日:2008-12-11
The present invention concerns novel bidentante optionally N-containing P-ligands of general Formula (I) embracing a two-ring-system and processes for synthesizing them, transition metal complexes of these compounds and their use as catalysts.
PROCESS FOR PREPARING CATIONIC RHODIUM COMPLEXES
申请人:Nedden Hans Guenter
公开号:US20100113256A1
公开(公告)日:2010-05-06
A process for the synthesis of a cationic rhodium complex comprises the steps of:
(a) forming a mixture of a rhodium-diolefin-1,3-diketonate compound and a phosphorus ligand in a ketone solvent,
(b) mixing an acid with the mixture to form a solution of the cationic rhodium complex,
(c) evaporating at least a portion of the solvent from the solution,
(d) optionally, treating the resulting complex with an ether, and
(e) treating the resulting complex with an alcohol.
The complex may be recovered and used as a catalyst, for example in hydrogenation reactions.