Design and Synthesis of Chiral Lewis Acid Catalysts for Aqueous Diels-Aider and Barbier Reactions
Keywords: Lewis acids, chiral, enantioselectivity, stereoselectivity, binaphthol, aqueous media, Diels-Alder, Barbier, lanthanide
AbstractWe report here the successful synthesis of two 3, 3' -difluorenyl binaphthols. In the divergent strategy employed in the synthesis, the 3,3' and 2,2'-positionsof (S)-(-)-1,1'-binaphthol were brominated and methylated, respectively, leading to the formation of a product that can be converted to a Grignard reagent. A Grignard addition to 9-fluorenone followed by deprotection afforded the target compounds. We also present here the method of testing their utility as ligands in chiral Lewis acid-catalyzed aqueous Barbier and Diels-Alder methodologies. The chiral Lewis acid complexes (CLAC) were generated in situ by mixing lanthanide triflates and 3,3'binaphthol derivatives. Among the six lanthanide triflates tested, only the Yb(OTf)3 -3,3'binaphtol derivative complex showed promising results for both model reactions.
How to Cite
Arco, S. D., & Miranda, J. T. (2006). Design and Synthesis of Chiral Lewis Acid Catalysts for Aqueous Diels-Aider and Barbier Reactions. KIMIKA, 22(1), 33-42. https://doi.org/10.26534/kimika.v22i1.33-42
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