1256124-09-0Relevant academic research and scientific papers
New chiral calixsalen chromium complexes: Recyclable asymmetric catalysts
Zulauf, Anais,Mellah, Mohamed,Schulz, Emmanuelle
, p. 11108 - 11114 (2010)
A chiral N,N'-bis(salicylidene)ethylenediamine (salen) polymer has been prepared by a condensation reaction between a thio-phenedisalicyladehyde derivative and (S,S)-cyclohexane-1,2-diamine. This polymeric compound was demonstrated to possess a cyclic structure with two to five repetitive units. The addition of chromium(II) salts led to the generation of a chiral catalyst that could be recovered as an insoluble powder. The performance of this new calixsalen-type catalyst was examined in various transformations, particularly in its ability to promote nucleophilic epoxide ring opening under heterogeneous conditions. The target products were obtained in high yields and with improved selectivity compared with those obtained by using analogous linear polymers. The arrangement of the catalytic sites in the cyclic structure is probably more suitable for the necessary cooperative bimetallic pathway of this demanding reaction. The catalyst could be successfully recycled. This approach represents the first use of calixsalen complexes under heterogeneous catalytic conditions.
Synthesis and characterization of original calix-salen type ligands
Ibrahim, Farah,Nasrallah, Houssein,Hong, Xiang,Mellah, Mohamed,Schulz, Emmanuelle,Hachem, Ali,Ibrahim, Ghassan,Jaber, Nada
, p. 9954 - 9961,8 (2012/12/12)
Polycondensation reactions between various modified disalicylaldehyde derivatives and two chiral diamines afforded in each case macrocyclic structures, named calix-salen. Mixtures of oligomers (dimers to pentamers) were qualitatively analyzed by Maldi-Tof
