1542136-76-4Relevant academic research and scientific papers
Efficient palladium catalysts containing original imidazolium-tagged chiral diamidophosphite ligands for asymmetric allylic substitutions in neat ionic liquid
Bravo, Maritza J.,Favier, Isabelle,Saffon, Nathalie,Ceder, Rosa M.,Muller, Guillermo,Gomez, Montserrat,Rocamora, Merce
, p. 771 - 779 (2014/03/21)
New imidazolium-tagged chiral diamidophosphite ligands, (S,S)-a and (R)-b, derived from (S,S)-N,N′-dibenzyl-1,2-cyclohexanediamine and (R)-N,N′-dimethyl-1,1′-binaphthyl-2,2′-diamine, respectively, and the corresponding palladium allylic complexes of general formula [PdCl(η3-2-Me-C3H4)(κ1P-L) ]BF4 (1a,b) and [Pd(η3-2-Me-C3H 4)(κ1P-L)2](BF4)3 (2a,b) were synthesized and fully characterized, including the X-ray crystal structure for 1b. These original Pd/L catalytic systems were applied in asymmetric allylic alkylation, amination, and sulfonylation using rac-3-acetoxy-1,3-diphenyl-1-propene as a substrate in neat ionic liquids, [bmim][PF6] and [Pyr][NTf2]. The best results in terms of enantioselectivity were obtained with the catalytic precursor 1b in [Pyr][NTf2]. The catalytic phase containing 1b for the allylic amination could be recycled up to six times without significant loss of asymmetric induction.
