1360824-99-2Relevant academic research and scientific papers
Synthetic scope and DFT analysis of the chiral binap-gold(I) complex-catalyzed 1,3-dipolar cycloaddition of azlactones with alkenes
Martin-Rodriguez, Maria,Castello, Luis M.,Najera, Carmen,Sansano, Jose M.,Larranaga, Olatz,De Cozar, Abel,Cossio, Fernando P.
supporting information, p. 2422 - 2433 (2014/01/06)
The 1,3-dipolar cycloaddition between glycine-derived azlactones with maleimides is efficiently catalyzed by the dimeric chiral complex [(Sa)-Binap AuTFA]2. The alanine-derived oxazolone only reacts with tert-butyl acrylate giving anomalous regiochemistry, which is explained and supported by Natural Resonance Theory and Nucleus Independent Chemical Shifts calculations. The origin of the high enantiodiscrimination observed with maleimides and tert-butyl acrylate is analyzed using DFT computed at M06/Lanl2dz//ONIOM(b3lyp/Lanl2dz: UFF) level. Several applications of these cycloadducts in the synthesis of new proline derivatives with a 2,5-trans-arrangement and in the preparation of complex fused polycyclic molecules are described.
Enantioselective 1,3-dipolar cycloadditions of azlactones and electrophilic alkenes catalyzed by dimeric BinapAuTFA complexes
Martín-Rodríguez, María,Nájera, Carmen,Sansano, José M.
supporting information; experimental part, p. 62 - 65 (2012/02/15)
Glycine-derived azlactones react with maleimides using (S)- or (R)-dimeric BinapAuTFA complexes affording the corresponding cycloadducts in good yields and high enantioselections (up to 99% ee). The intermediate carboxylic acids are treated with trimethylsilyldiazomethane and isolated as 1-pyrroline methyl esters. These cycloadducts are transformed into exo-proline derivatives by reduction with NaBH3CN in acidic media. On the other hand, N-benzoylalanine-derived oxazolone reacts with tert-butyl acrylate providing the cycloadduct with the ester group at the 3-position with a trans-relative configuration with respect to the methyl ester group. Georg Thieme Verlag Stuttgart. New York.
