Regiodivergent Enantioselective γ-Additions of Oxazolones to 2,3-Butadienoates Catalyzed by Phosphines: Synthesis of α,α-Disubstituted α-Amino Acids and N,O-Acetal Derivatives
摘要:
Phosphine-catalyzed regiodivergent enantioselective C-2- and C-4-selective gamma-additions of oxazolones to 2,3-butadienoates have been developed. The C-4-selective gamma-addition of oxazolones occurred in a highly enantioselective manner when 2-aryl-4-alkyloxazol-5-(4H)-ones were employed as pronudeophiles. With the employment of 2-alkyl-4-aryloxazol-5-(4H)-ones as the donor, C-2-selective gamma-addition of oxazolones took place in a highly enantioselective manner. The C-4-selective adducts provided rapid access to optically enriched alpha,alpha-disubstituted alpha-amino acid derivatives, and the C-2-selective products led to facile synthesis of chiral N,O-acetals and gamma-lactols. Theoretical studies via DFT calculations suggested that the origin of the observed regioselectivity was due to the distortion energy that resulted from the interaction between the nudeophilic oxazolide and the electrophilic phosphonium intermediate.
Diastereoselective Synthesis of Oxazoloisoindolinones via Cascade Pd-Catalyzed <i>ortho</i>-Acylation of <i>N</i>-Benzoyl α-Amino Acid Derivatives and Subsequent Double Intramolecular Cyclizations
作者:Kun Jing、Xiang-Nan Wang、Guan-Wu Wang
DOI:10.1021/acs.joc.8b02509
日期:2019.1.4
The first cascade diastereoselective synthesis of oxazoloisoindolinones via the palladium-catalyzed decarboxylative ortho-acylation of N-benzoyl α-aminoacid derivatives followed by double intramolecular cyclizations has been demonstrated. This reaction, using α-aminoacids as directing groups and α-oxocarboxylic acids as the acylation source, features a broad substrate scope, good functional group
A new strategy, a transient homocoupling dimer strategy, for direct catalytic oxidative cross-enolate coupling reactions is developed. Cross-enolate coupling products bearing a (contiguous) tetrasubstituted carbon center were obtained chemoselectively without the need for stoichiometric amounts of strong bases/metal oxidants, and thus, the present catalysis provides a general method for the synthesis
Asymmetric trifluoromethylthiolation of azlactones under chiral phase transfer catalysis
作者:Marina Sicignano、Ricardo I. Rodríguez、Vito Capaccio、Fabio Borello、Rafael Cano、Francesco De Riccardis、Luca Bernardi、Sergio Díaz-Tendero、Giorgio Della Sala、José Alemán
DOI:10.1039/d0ob00476f
日期:——
The first enantioselective method for the installation of the SCF3 group at the C-4 position of azlactones is described in the present communication under quinidinium phasetransfercatalysis. The higher performance of substrates containing electron-rich 2-aryl groups at the azlactone was rationalized using DFT calculations.
We developed a catalytic aerobic method to synthesize α,α-disubstituted α-amino acids through cross-dehydrogenativecoupling of azlactones. Combining an iron catalyst with a bisoxazolidine ligand resulted in high catalytic performance, and cross-coupling with an indole proceeded smoothly underaerobicconditions. A wide variety of α-aryl and aliphatic amino acid derived azlactones were applied to the
[EN] PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA AGONISTS, METHOD OF PREPARATION AND USES THEREOF<br/>[FR] AGONISTES DU RÉCEPTEUR GAMMA ACTIVÉ PAR LES PROLIFÉRATEURS DES PEROXYSOMES, LEUR PROCÉDÉ DE PRÉPARATION ET LEURS UTILISATIONS
申请人:UNIV D'AIX-MARSEILLE
公开号:WO2018011230A1
公开(公告)日:2018-01-18
The present invention relates to new peroxisome proliferator-activated receptor gamma (PPARϒ) agonists, and their uses as in the prevention and/or treatment of type 2 diabetes, impaired glucose tolerance, insulin resistance syndrome, hyperlipidemia, metabolic syndrome, visceral obesity, obesity, hyperlipidemia and hypertriglyceridemia. The preparation said compounds is also described.