Enantioselective Catalytic Conjugate Addition of Dialkylzinc Reagents using Copper–Phosphoramidite Complexes; Ligand Variation and Non-linear Effects
作者:Leggy A Arnold、Rosalinde Imbos、Alessandro Mandoli、André H.M de Vries、Robert Naasz、Ben L Feringa
DOI:10.1016/s0040-4020(00)00142-3
日期:2000.4
cyclohexenone and chalcone in order to assess the structural features that are important for stereocontrol. A sterically demanding amine moiety is essential to reach high e.e.’s. Enantioselectivities for chalcones up to 89% and for cyclic enones up to 98% were found. Studies on non-linear effects with the best ligands for both cyclohexenone and chalcone showed clear non-linear effects for both cyclic
METHOD FOR HYDROFORMYLATION OF UNSATURATED COMPOUNDS
申请人:Franke Robert
公开号:US20140024860A1
公开(公告)日:2014-01-23
The invention relates to a method for hydroformylation of unsaturated compounds such as olefins and alkynes using mixtures of synthesis gas (CO/H
2
), in which either the unsaturated compounds and a catalyst are heated to a reaction temperature of 60 to 200° C. and the synthesis gas is then added, or the unsaturated compounds and the catalyst are brought into contact with pure CO at normal temperature in a preformation step, then are heated to reaction temperature and on reaching the reaction temperature the CO is replaced by the synthesis gas. The pressure is 1 to 200 bar and the CO:H
2
ratio in the synthesis gas is in the range from 1:1 to 50:1. The iridium catalyst used comprises a phosphorus-containing ligand in the iridium:ligand ratio in the range from 1:1 to 1:100. With high catalyst activities and low catalyst use, very high turnover frequencies are achieved.
[EN] SYNTHESIS OF CHROMANE COMPOUNDS AND THEIR DERIVATIVES BY A COPPER-CATALYZED CONJUGATE ADDITION REACTION<br/>[FR] SYNTHÈSE DE COMPOSÉS DE CHROMANE ET DE LEURS DÉRIVÉS PAR UNE RÉACTION D'ADDITION CONJUGUÉE CATALYSÉE PAR DU CUIVRE
申请人:DSM IP ASSETS BV
公开号:WO2015059129A1
公开(公告)日:2015-04-30
The present invention relates to the preparation of chromane compounds and their derivatives by a copper-catalyzed conjugate addition reaction. It has been observed that in highly stereoselective manner a methyl group can be introduced to the 2 position of chromane ring by reaction of a chromenone with Al(CH3)3 in the presence of a Cu(I) salt and specific chiral phosphoramidites. The compounds obtained are important intermediates particularly for the synthesis of chiral tocopherols.
[EN] PROCESS FOR PREPARING SUBSTITUTED PHENYLALKANES<br/>[FR] PROCÉDÉ POUR PRÉPARER DES PHÉNYLALCANES SUBSTITUÉS
申请人:MALLINCKRODT LLC
公开号:WO2016007823A1
公开(公告)日:2016-01-14
The invention provides methods for preparing substituted phenylalkanes. In particular, the processes comprise reacting a phenyl boronic compound with an α-β unsaturated carbonyl-containing compound via an asymmetric 1,4-addition reaction. The processes may be useful in the synthesis of tapentadol.
An asymmetric version of the Nicholasreaction involving the use of chiral phosphoramidite ligands has been developed. Treatment of a cobalt carbonyl complexed propargylicalcohol with two equivalents of the chiral ligand, followed by reaction with a silyl enol ether in the presence of a Lewis acid, afforded, after decomplexation, the desired product in up to 74% ee for the carbon-carbon bond forming