Synthetic scope and DFT analysis of the chiral binap–gold(I) complex-catalyzed 1,3-dipolar cycloaddition of azlactones with alkenes
نویسندگان
چکیده
The 1,3-dipolar cycloaddition between glycine-derived azlactones with maleimides is efficiently catalyzed by the dimeric chiral complex [(S a)-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.
منابع مشابه
Binap-gold(I) versus Binap-silver trifluoroacetate complexes as catalysts in 1,3-dipolar cycloadditions of azomethine ylides.
The 1,3-dipolar cycloaddition between azomethine ylides and alkenes is efficiently catalysed by [{(S(a))-Binap-Au(tfa)}(2)] (Binap=2,2'-bis(diphenylphosphino)-1,1'-binaphthyl; tfa=trifluoroacetyl). Maleimides, 1,2-bis(phenylsulfonyl)ethylene, chalcone and nitrostyrene were suitable dipolarophiles even when using sterically hindered 1,3-dipole precursors. The results obtained in these transforma...
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