Fernandes, Talita de A., Vizcaíno-Milla, Pascuala, Ravasco, João M.J.M., Ortega-Martínez, Aitor, Sansano, Jose M., Nájera, Carmen, Costa, Paulo R.R., Fiser, Béla, Gómez Bengoa, Enrique
Bifunctional primary amine 2-aminobenzimidazole organocatalyst anchored to trans-cyclohexane-1,2-diamine in enantioselective conjugate additions of aldehydes
Tetrahedron: Asymmetry. 2016, 27(2-3): 118-122. doi:10.1016/j.tetasy.2015.12.004
URI: http://hdl.handle.net/10045/52712
DOI: 10.1016/j.tetasy.2015.12.004
ISSN: 0957-4166 (Print)
Abstract: 
Bifunctional chiral primary amine 8 containing an (S,S)-trans-cyclohexane-1,2-diamine scaffold and a 2-benzimidazole unit is used as a general organocatalyst for the Michael addition of α,α-branched aldehydes to nitroalkenes and maleimides. The reactions take place, with 20 mol % of catalyst in dichloromethane at rt for nitroalkenes and with 15 mol % catalyst loading in toluene at 10 °C for maleimides, in good yields and enantioselectivities. DFT calculations demonstrate the bifunctional character of this organocatalyst activating the aldehyde by enamine formation and the Michael acceptor by double hydrogen bonding.
Keywords:Bifunctional, Enantioselective, Aldehydes
Elsevier
info:eu-repo/semantics/article