188289-37-4Relevant academic research and scientific papers
Synthesis and characterization of new amine-imine ligands based on trans-2,5-disubstituted pyrrolidines
Sweet, James A.,Cavallari, Jennifer M.,Price, William A.,Ziller, Joseph W.,McGrath, Dominic V.
, p. 207 - 211 (1997)
We present a modular synthesis of a new class of chiral N,N-chelating ligands containing the C2-symmetric trans-2,5-disubstituted pyrrolidine moiety linked to a pyridine ring. (-)-2-[(2R,5R)-2,5-Dimethylpyrrolidin-1-ylmethyl]pyridine (11, (R,R)-MePMP), (-)-2-[2((2R,5R)-2,5-dimethylpyrrolidin- (12, (R,R)-MePEP), and (+)-2-[(2R,5R)-2,5-diphenylpyrrolidin-1-ylmethyl]pyridine (13, (R,R)-PhPMP) have been prepared. The X-ray structure of the (Λ3-allyl)Pd complex of (R,R)-MePMP (11) is reported.
Chiral amine-imine ligands based on trans-2,5-disubstituted pyrrolidines and their application in the palladium-catalyzed allylic alkylation
Chen, Hongfeng,Sweet, James A.,Lam, Kin-Chung,Rheingold, Arnold L.,McGrath, Dominic V.
experimental part, p. 1672 - 1682 (2009/12/04)
A series of amine-imine bidentate ligands based on a trans-2,5-disubstituted pyrrolidine and pyridine moieties have been prepared. The use of these ligands in the palladium-catalyzed allylic alkylation reaction of rac-(E)-1,3-diphenylprop-2-enyl acetate is reported. The results suggest that these ligands are good catalyst precursors for the reaction. Electronic modification on the pyridine ring of the ligands does not have a significant effect on the enantioselectivity of the reaction but does on the reaction rate, while structural modification on either the pyridine or the pyrrolidine moiety affords dramatic changes on the outcome of the stereochemistry. Evidence from various studies suggested that during the palladium-catalyzed allylic alkylation reaction, nucleophilic attack onto the 1,3-diphenylallyl moiety in the transition state occurs mainly trans to the pyridine ring of the less stable conformation of the palladium complexes.
A new class of chiral lewis basic metal-free catalysts for stereoselective allylations of aldehydes
Simonini, Valentina,Benaglia, Maurizio,Pignataro, Luca,Guizzetti, Stefania,Celentano, Giuseppe
experimental part, p. 1061 - 1065 (2009/04/06)
A new class of amine N-oxides derived from trans-2,5-diphenylpyrrolidine were synthesized in enantiomerically pure form and tested as metal-free catalysts in the reaction of aldehydes with allyl(trichloro)silane to afford homoallylic alcohols. The products were obtained in fair to good yields and up to 85% ee. The behavior of structurally different catalysts and the influence of a coordinating unit present in the organocatalyst on controlling the stereochemical efficiency of the reaction were also investigated. Noteworthy a catalyst capable of promoting the allylation of aliphatic aldehydes with an almost unprecedent and unusually high enantioselectivity, up to 85%, was identified. Georg Thieme Verlag Stuttgart.
