6283-03-0Relevant academic research and scientific papers
Method for synthesis of (R)-1-(4-methyl phenyl) ethylamine
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Paragraph 0103; 0107-0108, (2018/11/03)
The invention discloses a method for synthesis of (R)-1-(4-methyl phenyl) ethylamine. The method includes: subjecting a compound 3 to deacylation to obtain (R)-1-(4-methyl phenyl) ethylamine in a C4-C10 monoalcohol solvent and in the presence of alkali metal hydroxide, wherein R refers to ethanoyl, propionyl or butyryl. The method is low in synthesis cost, simple in step, safe in operation, low inby-products, simple in aftertreatment, easy to purify intermediate products and final products, high in whole yield, high in final product purity and easy in industrialization.
1,1-Diacyloxy-1-phenylmethanes as versatile N-acylating agents for amines
Chapman, Robert. S.L.,Tibbetts, Joshua. D.,Bull, Steven. D.
, p. 5330 - 5339 (2018/06/15)
1,1-Diacyloxy-1-phenylmethanes and 1-pivaloxy-1-acyloxy-1-phenylmethanes have been used as bench stable N-acylating reagents for primary and secondary amines and anilines under solvent-free conditions to afford their corresponding amides in good yield.
Umpolung Amide Synthesis using substoichiometric N-iodosuccinimide (NIS) and oxygen AS a terminal oxidant
Schwieter, Kenneth E.,Shen, Bo,Shackleford, Jessica P.,Leighty, Matthew W.,Johnston, Jeffrey N.
supporting information, p. 4714 - 4717 (2015/04/27)
Umpolung Amide Synthesis (UmAS) provides direct access to amides from an α-bromo nitroalkane and an amine. Based on its mechanistic bifurcation after convergent C-N bond formation, depending on the absence or presence of oxygen, UmAS using substoichiometric N-iodosuccinimide (NIS) under aerobic conditions has been developed. In combination with the enantioselective preparation of α-bromo nitroalkane donors, this protocol realizes the goal of enantioselective α-amino amide and peptide synthesis based solely on catalytic methods.
Dynamic double kinetic resolution of amines and alcohols under the cocatalysis of Raney nickel/Candida antarctica lipase B: From concept to application
Xia, Bo,Cheng, Guilin,Lin, Xianfu,Wu, Qi
supporting information, p. 2917 - 2923 (2014/05/20)
Herein, we have established a dynamic double kinetic resolution (DDKR) strategy under the co-catalysis of Raney nickel and Candida antarctica lipase B (CAL-B) for the one-pot simultaneous resolution of primary amines and secondary alcohols (or esters). The DDKR strategy was successfully applied to the resolution of a series of racemic amines and secondary alcohols (or esters) as well as mexiletine, an important antiarrhythmic agent. The catalysts could be recycled and reused several times with the same high activity. Scale-up experiments were also successful. As a more atom-economical and efficient process than traditional simple kinetic resolutions, the DDKR strategy can be widely used to prepare optically pure amines and alcohols.
Application of acyclic chiral auxiliaries on alkylation reactions
Gardu?o-Castro, Monserrat H.,Hernández-Rodríguez, Marcos
supporting information, p. 193 - 196 (2014/01/06)
The application in alkylation reactions of an acyclic chiral auxiliary is described. The synthesis is straightforward from a chiral primary amine and a double acylation. A characteristic of this auxiliary is its modular design formed by an achiral part (acyl) and a chiral component (primary amine) so it can be tuned for different reactions without difficulty. The alkylation proceeds with excellent diastereoselectivity because the conformational flexibility of the enolate is restricted by the formation of a chelate and the allylic 1,3-strain.
Self-disproportionation of enantiomers of non-racemic chiral amine derivatives through achiral chromatography
Nakamura, Tsuyoshi,Tateishi, Kaori,Tsukagoshi, Shiori,Hashimoto, Saori,Watanabe, Shotaro,Soloshonok, Vadim A.,Ace?a, José Luis,Kitagawa, Osamu
experimental part, p. 4013 - 4017 (2012/07/14)
Efficient self-disproportionation of enantiomers of several non-racemic chiral amines was achieved through conversion to N-acetamides and subsequent MPLC using an achiral column. The MPLC of these non-racemic N-acetamide derivatives gave the chart having a clear boundary between two fractions. Thus, in the less polar fraction, remarkable enantiomer enrichment was observed (>99%ee), while the ee of more polar fraction was considerably reduced. The magnitude of the enantiomer enrichments and depletions strongly depended on substituent on the amino group.
Cyclohexylamine oxidase as a useful biocatalyst for the kinetic resolution and dereacemization of amines
Leisch, Hannes,Grosse, Stephan,Iwaki, Hiroaki,Hasegawa, Yoshie,Lau, Peter C.K.
, p. 39 - 45 (2012/03/07)
The biocatalytic performance of a cloned cyclohexylamine oxidase derived from Brevibacterium oxydans IH-35A towards structurally different amines was investigated. Cycloalkyl primary amines, alkyl aryl amines, and α-carbon-substituted aliphatic amines were identified as suitable substrates for the biocatalyst based on an activity assay. Kinetic resolutions of several amines by either recombinant whole cells or crude enzyme extracts prepared therefrom gave enantiomerically pure (R)-amines besides the corresponding ketones. When cyclohexylamine oxidase in combination with a borane-ammonia complex as reducing agent was applied to the deracemization of several substrates, excellent enantiomeric ratios (>99:1) and good isolated yields (62%-75%) of the corresponding (R)-amines were obtained.
Asymmetric synthesis of (+)-galbelgin, (-)-kadangustin J, (-)-cyclogalgravin and (-)-pycnanthulignenes A and B, three structurally distinct lignan classes, using a common chiral precursor
Rye, Claire E.,Barker, David
experimental part, p. 6636 - 6648 (2011/10/18)
The enantioselective synthesis of three structurally distinct classes of lignan from a single, aza-Claisen-derived, chiral morpholine amide is reported. The class of lignan formed is dependent on the substitution pattern in the aryl rings and choice of pr
Synthesis and reactions of α-fluoro-α-amino amides
Bailey, Patrick D.,Boa, Andrew N.,Clayson, Joanne
experimental part, p. 1724 - 1736 (2009/05/09)
N-((S)-1-Phenylethyl)halofluoroethanamides have been investigated as precursors to N-protected α-fluoro-α-amino amides by nucleophilic displacement of halide with nitrogen nucleophiles such as potassium phthalimide, sodium succinimide, sodium glutarimide, trimethylamine and sodium azide. With single diastereoisomers of the iodofluoroethanamide, clean inversion of configuration occurs at room temperature, but subsequent epimerisation may occur as a result of the liberated iodide. The α-fluoro-α-amino amides made underwent a wide variety of reactions depending on conditions, but in many cases the carbon-fluorine bond was compromised. However, reacting trimethylamine and N-((S)-1-phenylethyl)iodofluoroethanamide gave the corresponding α-fluorobetaine amide, and subsequent acidic hydrolysis led to α-fluorobetaine as the first example of an 'unprotected' α-fluoroamino acid.
