corresponding succinimides in good yields and enantioselectivities. DFT calculations support the stereochemical results and the role played by the solvents. Chiralprimary amines containing the (R,R)- and (S,S)-trans-cyclohexane-1,2-diamine scaffold and a pyrimidin-2-yl unit are synthesized and used as general organocatalysts for the Michael reaction of α-branched aldehydes to maleimides. The reaction
An Asymmetric Michael Addition of α,α-Disubstituted Aldehydes to Maleimides Leading to a One-Pot Enantioselective Synthesis of Lactones Catalyzed by Amino Acids
作者:Christoforos G. Kokotos
DOI:10.1021/ol4008662
日期:2013.5.17
A cheap and fast construction of both enantiomers of substituted succinimides is reported. α- or β-amino acids, such as β-phenylalanine and α-tert-butyl aspartate, were found to be efficient organocatalysts for the reaction between α,α-disubstituted aldehydes and maleimides. Products containing contiguous quaternary-tertiary stereogenic centers are obtained in high to quantitative yields and excellent
amine-salicylamide derived from chiral trans-cyclohexane-1,2-diamine was used as an organocatalyst for the enantioselective conjugate addition of aldehydes, mainly α,α-disubstituted to N-substituted maleimides. The reaction was performed in toluene as a solvent at room temperature. The corresponding enantioenriched adducts were obtained with high yields and enantioselectivities up to 94%. Theoretical calculations
commercially available chiral 1,2-diamines were used as organocatalysts for the enantioselective conjugate addition of aldehydes, including α,α-disubstituted, to maleimides. The reaction was carried out in the presence of hexanedioic acid as an additive in aqueous solvents at room temperature. By employing (1S,2S)- and (1R,2R)-cyclohexane-1,2-diamine as organocatalysts, the corresponding Michael adducts bearing
The authors thank the Spanish Ministerio de Economia y Competitividad (MEC) (projects CTQ2010-20387, CTQ2010-21263-C02, and Consolider Ingenio 2010, CSD2007-00006), the Fondos Europeos para el Desarrollo Regional (FEDER), the COST Action CM0905 “Organocatalysis”, the Generalitat Valenciana (Prometeo/2009/039), the Basque Government (GV grant IT-291-07), the University of Alicante, and the University
作者感谢西班牙经济与竞争部长 (MEC)(项目 CTQ2010-20387、CTQ2010-21263-C02 和 Consolider Ingenio 2010、CSD2007-00006)、Fondos Europeos para el Desarrollo、CM05 “Organocatalysis”、Generalitat Valenciana (Prometeo/2009/039)、巴斯克政府(GV grant IT-291-07)、阿利坎特大学和巴斯克地区大学的财政支持。