Palladium-Catalyzed Arylation of Enoates with Iodobenzene: Stereoselective Synthesis of Trisubstituted Olefins
摘要:
The Heck reaction between E- and Z-enoates and iodobenzene was studied in the presence of Pd(OAc)(2). The stereochemistry in resulting adducts was dependent on the enoate geometry (stereospecific reaction). Best yields were obtained from Z-isomers in acetone using Ag2CO3 as base. The main cationic palladium intermediates possibly involved in the catalytic cycle could be intercepted and characterized by electrospray ionization mass spectrometry (ESI-MS). The stereoselectivity observed was rationalized through the classic mechanism of the Heck reaction.
Combined oxidative and reductive carbonylation of terminal alkynes with palladium iodide-thiourea catalysts
作者:Bartolo Gabriele、Giuseppe Salerno、Mirco Costa、Gian Paolo Chiusoli
DOI:10.1016/0022-328x(95)05539-2
日期:1995.11
Oxidative carbonylation of alkynes can be carried out catalytically in the absence of added oxidants if it is coupled with a reductive carbonylation process at the expense of the same alkyne invilved in the oxidative process. Maleic esters (from oxidative carbonylation) and unsaturated lactones (from reductive carbonylation) are the main products formed under the catalytic action of palladiumiodide complexes
2- [5- (5-carbamimidoyl-1H-heteroaryl)-6-hydroxybiphenyl-3-yl]-succinic acid derivatives as factor viia inhibitors
申请人:Axys Pharmaceuticals, Inc.
公开号:US20030114457A1
公开(公告)日:2003-06-19
The present invention relates to novel inhibitors of Factors VIIa, IXa, Xa, XIa, in particular Factor VIIa, pharmaceutical compositions comprising these inhibitors, and methods for using these inhibitors for treating or preventing thromboembolic disorders. Processes for preparing these inhibitors are also disclosed.
Stereochemical course of the palladium-catalysed arylation of disubstituted activated alkenes with benzoyl chloride
作者:Alwyn Spencer
DOI:10.1016/s0022-328x(00)82516-4
日期:1982.12
The palladium-catalysedarylation of ten 1,1- and 1,2-disubstituted activated alkenes with benzoyl chloride was studied. In most cases, more than one product was formed. The stereochemical course of the arylation appears to be controlled by the polarity of the double bond, the tendency to cis (suprafacial) alkene insertion and subsequent re-elimination, steric hindrance in the alkylpalladium(II) species
Asymmetrichydrogenation of maleic and fumaric acid derivatives with iridium catalysts based on N,P ligands provides an efficient route to chiral enantioenriched succinates. A new catalyst derived from a 2,6‐difluorophenyl‐substituted pyridine‐phosphinite ligand was developed and enables the conversion of a wide range of 2‐alkyl and 2‐arylmaleic acid diesters into the corresponding succinates in high
Steric Effects on the Stereochemistry of Old Yellow Enzyme-Mediated Reductions of Unsaturated Diesters: Flipping of the Substrate within the Enzyme Active Site Induced by Structural Modifications
作者:Elisabetta Brenna、Francesco G. Gatti、Alessia Manfredi、Daniela Monti、Fabio Parmeggiani
DOI:10.1002/adsc.201200471
日期:2012.10.8
The ene-reductase-mediated reduction of the carbon-carbon double bond of some alkyl 2-substituted butenedioates was investigated. The stereochemical outcome of the reaction was found to be influenced by stericeffects. Ethyl and butyl citraconates were converted into the corresponding alkyl (R)-2-methylsuccinates with excellent enantioselectivity, whereas ethyl and butyl mesaconates were completely