enantioselective decarboxylative [4 + 2]-annulation of ethynyl benzoxazinanones with azlactones has been developed under cooperative copper and bifunctional tertiary aminourea catalysis. This direct and modular approach combines dipolar copper-allenylidene intermediates with azlactone enolates and allows for the synthesis of α-quaternary α-acylaminoamides as a single diastereomer generally in high yields
Catalytic, Enantioselective α‐Alkylation of Azlactones with Nonconjugated Alkenes by Directed Nucleopalladation
作者:Sri Krishna Nimmagadda、Mingyu Liu、Malkanthi K. Karunananda、De‐Wei Gao、Omar Apolinar、Jason S. Chen、Peng Liu、Keary M. Engle
DOI:10.1002/anie.201814272
日期:2019.3.18
palladium(II)‐catalyzed enantioselective α‐alkylation of azlactones with nonconjugated alkenes is described. The reaction employs a chiral BINOL‐derived phosphoric acid as the source of stereoinduction, and a cleavable bidentate directing group appended to the alkene to control the regioselectivity and stabilize the nucleopalladated alkylpalladium(II) intermediate in the catalytic cycle. A wide range of
Dynamic Kinetic Resolution of Azlactones by a Chiral <i>N</i>,<i>N</i>-Dimethyl-4-aminopyridine Derivative Containing a 1,1′-Binaphthyl Unit: Importance of Amide Groups
作者:Hiroki Mandai、Kohei Hongo、Takuma Fujiwara、Kazuki Fujii、Koichi Mitsudo、Seiji Suga
DOI:10.1021/acs.orglett.8b01960
日期:2018.8.17
resolution (DKR) of azlactones in the presence of benzoic acid and a binaphthyl-based N,N-4-dimethylaminopyridine (DMAP) derivative 1i having two amide groups at the 3,3′-positions of a binaphthyl unit is developed. The reaction proceeded smoothly with a wide range of azlactones to provide α-amino acid derivatives with good to high enantiomeric ratios (er’s). A multigram-scale reaction (2.5 g) for the
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.
Highly Stereoselective [4+2] Cycloaddition of Azlactones to β,γ-Unsaturated α-Ketoesters Catalyzed by an Axially Chiral Guanidine Base
作者:Masahiro Terada、Hiroyuki Nii
DOI:10.1002/chem.201003015
日期:2011.2.7
cycloaddition reaction of azlactones with β,γ‐unsaturated α‐ketoesters was demonstrated by taking advantage of the multiple reactive sites on the azlactone with the use of an axially chiral guanidine‐base catalyst. The most likely reaction pathway involves three consecutive steps to provide a facile access to α‐amino δ‐lactones with a sugar framework in a highly stereoselective manner (see scheme).