145166-01-4Relevant academic research and scientific papers
Synthesis of some new tertiary amines and their application as co-catalysts in combination with l-proline in enantioselective Baylis-Hillman reaction between o-nitrobenzaldehyde and methyl vinyl ketone
Tang, Hongying,Zhao, Guofeng,Zhou, Zhenghong,Zhou, Qilin,Tang, Chuchi
, p. 5717 - 5721 (2006)
A chiral benzodiazepine derivative 1 was synthesized starting from o-nitrobenzoyl chloride and methyl l-prolinate hydrochloride. Diastereomeric (1R,2R,1′S)-(+)-2-[N-methyl-N-(α-phenylethyl)amino]cyclohexanol 3a and (1S,2S,1′S)-(+)-2-[N-methyl-N-(α-phenylethyl)amino]cyclohexanol 3b were synthesized starting from (S)-α-phenylethylamine and cyclohexene oxide via ring-opening, diastereomer separation and N-methylation. (S,S)-octahydrodipyrrolo[1,2-a:1′,2′-d]pyrazin 5 was synthesized from methyl l-prolinate. Chiral tertiary amines 1, 3a, 3b and 5 almost cannot catalyze the Baylis-Hillman reaction between o-nitrobenzaldehyde and methyl vinyl ketone (MVK). However, they functioned as efficient catalysts for this reaction in the presence of l-proline. The corresponding adducts were obtained in good yields with enantioselectivity of 83% ee, 81% ee, 51% ee and 66% ee, respectively.
Molecular modeling of salt (lithium chloride) effects on the enantioselectivity of diethylzinc addition to benzaldehyde in the presence of chiral β-amino alcohols
Sosa-Rivadeneyra, Martha,Munoz-Muniz, Omar,Anaya de Parrodi, Cecilia,Quintero, Leticia,Juaristi, Eusebio
, p. 2369 - 2375 (2003)
β-Amino alcohols (S,S,S)-1 and (R,R,S)-1, derived from cyclohexene oxide and containing α-phenylethyl auxiliaries, were examined as chiral promoters in the addition of diethylzinc to benzaldehyde. In agreement with literature precedent, the N-α-phenylethy
Synthesis and characterization of chiral aza-macrocycles and study of their enantiomer recognition ability for organo-phosphoric acid and phosphonic acid derivatives by 31P NMR and fluorescence spectroscopy
Khanvilkar, Aditya N.,Bedekar, Ashutosh V.
, p. 2742 - 2748 (2016)
Two diastereomers of optically active N,O-containing new macrocycles with dual chirality of the ring and pendent group were synthesized and characterized. The difference in the accessibility of the cavity was explored to discriminate the enantiomers of the derivatives of organo-phosphoric and phosphonic acids by 31P NMR and fluorescence spectroscopy.
Chiral tertiary amine/L-proline cocatalyzed enantioselective Morita-Baylis-Hillman (MBH) reaction
Tang, Hongying,Zhao, Guofeng,Zhou, Zhenghong,Gao, Peng,He, Liangnian,Tang, Chuchi
, p. 126 - 135 (2008/09/18)
Four types of chiral amines have been synthesized starting from readily available chiral sources. These chiral amines in combination with L-proline have been found to be efficient cocatalysts for the asymmetric Morita-Baylis-Hillman (MBH) reaction between methyl vinyl ketone (MVK) and aromatic aldehydes. The corresponding adducts were formed in reasonable chemical yields and with good enantioselectivities (up to 83 % ee). Moreover, parallel cocatalytic reactions with the two enantiomers of chiral amine 4 and L-proline revealed that it is the proline stereochemistry that determines the configuration of the newly formed chiral center. In addition, the existence of the free hydroxy group in amine 4a enhanced the enantioselectivity of the reaction. Based on these findings, a plausible mechanism for this cocatalytic MBH reaction has been proposed. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Resolution of racemic 2-aminocyclohexanol derivatives and their application as ligands in asymmetric catalysis
Schiffers, Ingo,Rantanen, Toni,Schmidt, Frank,Bergmans, Werner,Zani, Lorenzo,Bolm, Carsten
, p. 2320 - 2331 (2007/10/03)
A preparatively easy and efficient protocol for the resolution of racemic 2-aminocyclohexanol derivatives is described, delivering both enantiomers with >99% enantiomeric excess (ee) by sequential use of (R)- and (S)-mandelic acid. A simple aqueous workup procedure permits the isolation of the amino alcohols in analytically pure form and the almost quantitative recovery of mandelic acid. Debenzylation of enantiopure trans-2-(N-benzyl)amino-1- cyclohexanol by hydrogenation and subsequent derivatization give access to a broad variety of diversely substituted derivatives. Furthermore, the corresponding cis isomers are readily available. Applications of these optically active aminocyclohexanols in catalyzed asymmetric phenyl transfer reactions to benzaldehydes and transfer hydrogenations of aryl ketones lead to products with up to 96% ee.
O.N-Bis(diphenylphosphino) Derivatives of Chiral trans- and cis-2-Aminocyclohexanols: Synthesis and Enantioselective Behaviour as Ligands in Rh-based Homogeneous Hydrogenation Catalysts
Pracejus, H.,Pracejus, G.,Costisella, B.
, p. 235 - 245 (2007/10/02)
trans- and cis-2-Methylamino cyclohexanols (MAC) were prepared in enantiomerically pure forms and transformed into O.N-bis(diphenylphosphino) derivatives ("PONP").An analogous trans-1R;2R-aminocyclohexanol PONP could only be isolated in an impure form, whereas the attempted synthesis of PONP's of diastereomeric trans-2-(N-α-phenylethylamino)-cyclohexanols failed.Cationic Rh(I)-chelates of the new PONP's catalyzed the enantioselective hydrogenation of dehydro-α-acylamino acids with /= 97percent ee.A comparison of the enantiodiscriminating properties of the MAC-PONP's with structurally related chiral ligands leads to surprising conclusions.
