271601-28-6Relevant articles and documents
Expanding the Toolbox of Heterogeneous Asymmetric Organocatalysts: Bifunctional Cyclopropenimine Superbases for Enantioselective Catalysis in Batch and Continuous Flow
Leonardi, Costanza,Brandolese, Arianna,Preti, Lorenzo,Bortolini, Olga,Polo, Eleonora,Dambruoso, Paolo,Ragno, Daniele,Di Carmine, Graziano,Massi, Alessandro
, p. 5473 - 5485 (2021/10/14)
A strategy for the immobilization of chiral 2,3-bisaminocyclopropenium salt (pre-catalyst) onto polystyrene and silica supports is presented together with a suitable procedure for the conversion into the corresponding cyclopropenimine superbase catalysts.
Chiral octahedral complexes of cobalt(III) as "organic catalysts in disguise" for the asymmetric addition of a glycine schiff base ester to activated olefins
Maleev, Victor I.,North, Michael,Larionov, Vladimir A.,Fedyanin, Ivan V.,Savel'Yeva, Tatyana F.,Moscalenko, Margarita A.,Smolyakov, Alexander F.,Belokon, Yuri N.
supporting information, p. 1803 - 1810 (2014/06/09)
Stereochemically inert and positively charged chiral complexes of cobalt(III) prepared from Schiff bases derived from chiral diamines and salicylaldehydes were shown to be efficient catalysts of the benchmark asymmetric phase-transfer Michael addition of nine activated olefins to O'Donnell's substrate. The reaction products had enantiomeric purities of up to 96%. DFT calculations were invoked to rationalize the stereochemistry of the addition.
Preparation of chiral amino esters by asymmetric phase-transfer catalyzed alkylations of schiff bases in a ball mill
Nun, Pierrick,Perez, Violaine,Calmes, Monique,Martinez, Jean,Lamaty, Frederic
, p. 3773 - 3779 (2012/04/23)
The asymmetric alkylation of Schiff bases under basic conditions in a ball mill was performed. The starting Schiff bases of glycine were prepared beforehand by milling protected glycine hydrochloride and benzophenone imine, in the absence of solvent. The Schiff base was then reacted with a halogenated derivative in a ball mill in the presence of KOH. By adding a chiral ammonium salt derived from cinchonidine, the reaction proceeded asymmetrically under phase-transfer catalysis conditions, giving excellent yields and enantiomeric excesses up to 75 %. Because an equimolar amount of starting material was used, purification was greatly simplified. Copyright