Switching Diastereoselectivity in Catalytic Enantioselective (3+2) Cycloadditions of Azomethine Ylides Promoted by Metal Salts and Privileged Segphos-Derived Ligands
Guilherme S. Caleffi, Olatz Larrañaga, Marcos Ferrándiz-Saperas, Paulo R. R. Costa, Carmen Nájera*, Abel de Cózar, Fernando P. Cossío*, José M. Sansano*
*Centro de Innovación en Química Avanzada (ORFEO-CINQA), 08193 Barcelona, Spain,
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G. S. Caleffi, O. Larrañaga, M. Ferrándiz-Saperas, P. R. R. Costa, C. Nájera, A. de Cózar, F. P. Cossío, J. M. Sansano, J. Org. Chem., 2019, 84, 10593-10605.
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Abstract
Depending on the use of copper(I) and silver(I) complexes with (S)-DM- or (S)-DTBM-Segphos as ligands, a catalytic enantioselective 1,3-dipolar cycloaddition between imino esters and electrophilic alkenes provides diastereodivergently exo- or endo-cycloadducts. Functional groups of the dipolarophile and the choice of the catalyst play an important role in promoting reverse diastereoselectivities.
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diastereoselectivity rationale
Key Words
1,3-dipolar cycloaddition, pyrrolidines
ID: J42-Y2019
