86013-68-5Relevant academic research and scientific papers
Ytterbium acetate promoted asymmetric reductive amination: Significantly enhanced stereoselectivity
Nugent, Thomas C.,El-Shazly, Mohamed,Wakchaure, Vijay N.
, p. 1297 - 1305 (2008/09/17)
(Chemical Equation Presented) Reductive amination of prochiral unhindered 2-alkanones 1 with (R)- or (S)-α-MBA in the presence of Yb(OAc) 3 (50-110 mol %), Raney-Ni, and hydrogen (120 psi) results in increased diastereoselectivity for the amine products 2 (80-89% de) with good yield (80-87%). The increased de is based on comparison with the best previously reported de's when using (R)- or (S)-α-MBA, regardless of the strategy employed [stepwise (isolation of ketimines) or one-pot (reductive amination)], reducing agent examined, or achiral Lewis acid or Bronsted acid examined. An in situ cis- to trans-ketimine isomerization mechanism, promoted by Yb(OAc)3, has been proposed to account for the observed increase in diastereoselectivity and suggests a new entry into the control of ketimine geometry.
SYNTHESIS OF AMINES WITH YTTERBIUM LEWIS ACIDS
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Page/Page column 25, (2008/06/13)
The invention relates to methods for producing primary, secondary, and tertiary amines and the corresponding enantiopure or enantioenriched primary or secondary amine products from secondary or tertiary amine diastereomers.
A simple diastereoselective synthesis of chiral nonracemic aliphatic amines
Grishina,Luk'yanenko,Borisenko
, p. 807 - 810 (2007/10/03)
An efficient procedure has been developed for the diastereoselective synthesis of chiral aliphatic amines (diastereoisomeric excess >96%) from (1S)-N-(1-methylethylidene)-1-phenylethylamine, i.e., Schiff base derived from the simplest ketone (acetone) and
CATALYTIC ALKYL GROUP EXCHANGE REACTION OF PRIMARY AND SECONDARY AMINES.
Murahashi,Yoshimura,Tsumiyama,Kojima
, p. 5002 - 5011 (2007/10/02)
It has been shown that primary and secondary amines undergo alkyl group exchange reactions upon treatment with palladium catalyst as depicted in an operationally simple and efficient reaction which provides a convenient method for synthesis of unsymmetrical amines. The application of the reaction for the preparation of various substituted amines and heterocyclic compounds such as hexahydropyrimidine tetrahydropyrimidine, imidazolidine, and imidazoles is described. The preparation of polyamines such as H//2N(CH//2)//mNH(CH//2)//nNH//2 (10) and H//2N(CH//2)//lNH(CH//2)//mNH(CH//2)//nNH//2 (l-n, equals 2,3; 11) is readily performed by the appadium-catalyzed reactions of azetidine (6) and aziridine (7) via azetine (9) and azirine intermediates. The mechanism the palladium-catalyzed reaction has been extensively studied on the carbonylation, racemization, and deuteurium-exchange reaction of (S)-( minus )- alpha -phenylethylamine (17).
