268556-72-5

Upstream product

• 2393-23-9 4-methoxy-benzylamine 
• 98-86-2 acetophenone 
• 98-81-7 1-bromovinylbenzene 

Downstream Products

• 308273-66-7 (S)-N-(4’-methoxybenzyl)-1-phenylethanamine 

Relevant academic research and scientific papers

Asymmetric hydrogenation of N-alkyl and N-aryl ketimines using chiral cationic Ru(diamine) complexes as catalysts: The counteranion and solvent effects, and substrate scope

Asymmetric hydrogenation of N-alkyl and N-aryl ketimines catalyzed by chiral cationic η6-arene-(N-monosulfonylated diamine) Ru(II) complexes has been investigated. Strong counteranion and solvent effects on the enantioselectivity were observed. The ruthenium catalyst bearing non-coordinating BArF- anion was found to be particularly effective for the hydrogenation of acyclic and exocyclic N-alkyl ketimines in the presence of (Boc)2O in dichloromethane or even under solvent-free conditions, providing chiral amines with up to >99% ee and full conversions. Alternatively, the ruthenium catalyst bearing achiral phosphate anion together with corresponding phosphoric acid as the additive was also efficient for the hydrogenation of N-alkyl ketimines in the absence of (Boc)2O with excellent enantioselectivities and full conversions. For N-aryl ketimines lower enantiomeric excesses were observed by using the ruthenium catalyst bearing BArF- anion. This catalytic protocol thus provides a facile and practical access to optically active amines and has been successfully employed in the gram-scale synthesis of enantiomerically pure (+)-sertraline.

Asymmetric hydrogenation of N-Alkyl ketimines with phosphine-free, chiral, cationic Ru-MsDPEN catalysts

(Solvent) free and easy: A phosphine-free, chiral, cationic Ru-MsDPEN complex [(S,S)-1] is found to be an efficient catalyst for the enantioselective hydrogenation of a range of often-problematic N-alkyl ketimines (see scheme). This new method provides a more practical and greener synthetic approach to optically active amines, particularly N-alkyl amines, such as Sertraline.

A highly enantioselective organocatalytic method for reduction of aromatic N-alkyl ketimines

A study has demonstrated the development of a highly enantioselective catalytic method for the reduction of aromatic N-alkyl ketimines by trichlorosilane under mild conditions using the newly designed Lewis base organocatalyst that incorporates C- and S-chirality. The S-chiral sulfinamide group in these catalysts plays a crucial role similar to the carboxamide groups as Lewis base for the activation of HSiCl3, and also serves as a source of chirality that the carboxamide group lacks for the asymmetric induction. The results of the study showed that excellent enantioselectivities of up to 99.6% ee and high yields were obtained for a wide range of substrates. Further works is also in progress to clarify the mechanism of the transformation and explore the full application scope of the present catalyst system.

Palladium-Catalyzed Cross-Coupling Reactions of Amines with Alkenyl Bromides: A New Method for the Synthesis of Enamines and Imines

The palladium-catalyzed cross-coupling reaction of alkenyl bromides with secondary and primary amines gives rise to enamines and imines, respectively. This new transformation expands the applicability of palladium-catalyzed C-N bond forming reactions (the Buchwald-Hartwig amination), which have mostly been applied to aryl halides. After screening of different ligands, bases, and solvents, the catalytic combination [Pd2(dba)3]/BINAP in the presence of NaOtBu in toluene gave the best results in the cross-coupling of secondary amines with 1-bromostyrene (dba=dibenzylideneacetone, BINAP=2,2′-bis(diphenylphosphino)-1,1′-binaphthyl). The corresponding enamines are obtained cleanly and in nearly quantitative yields. However, steric hindrance seems to be a limitation of the reaction, as amines carrying large substituents are not well converted. The same methodology can be applied to the coupling of secondary amines with 2-bromostyrene. Moreover, the reaction with substituted 2-bromopropenes allows regioselective synthesis of isomerizable terminal enamines without isomerization of the double bond. The best catalytic conditions for the cross-coupling of 1-bromostyrene with primary amines include again the use of the Pd°/BINAP/NaOtBu system. The reaction gives rise to the expected imines in very short times and with low catalyst loadings. A set of structurally diverse imines can be prepared by this methodology through variations in the structure of both coupling partners. However, 2-bromostyrene failed to give good results in this coupling reaction, probably due to product inhibition of the catalytic cycle. Competition experiments of vinyl versus aryl amination reveal that the reaction occurs preferentially on vinyl bromides.

Application of monodentate secondary phosphine oxides, a new class of chiral ligands, in Ir(I)-catalyzed asymmetric imine hydrogenation

(Matrix presented) Secondary phosphine oxides were prepared from R 1PCl2 and R2MgBr, followed by hydrolysis. They were obtained in an enantiopure form by preparative chiral HPLC. These new monodentate ligands were tested in the iridium-catalyzed hydrogenation of imines at 25 bar. Enantioselectivities up to 76% were obtained at L/lr = 2. Addition of pyridine (Pyr/lr = 1:2) raised the ee to 83%. Using pyridine as an additive allowed reduction of the L/lr ratio to 1 without reduction of ee.

Enantioselective catalytic addition of HCN to ketoimines. Catalytic synthesis of quaternary amino acids.

[formula: see text] Highly enantioselective addition of HCN to ketoimines has been achieved for the first time using readily accessible and recyclable Schiff base catalysts. Essentially quantitative isolated yield and enantioselectivity of up to 95% ee wa