7713-69-1Relevant academic research and scientific papers
Photometric Characterization of the Reductive Amination Scope of the Imine Reductases from Streptomyces tsukubaensis and Streptomyces ipomoeae
Matzel, Philipp,Krautschick, Lukas,H?hne, Matthias
, p. 2022 - 2027 (2017/10/07)
Imine reductases (IREDs) have emerged as promising enzymes for the asymmetric synthesis of secondary and tertiary amines starting from carbonyl substrates. Screening the substrate specificity of the reductive amination reaction is usually performed by time-consuming GC analytics. We found two highly active IREDs in our enzyme collection, IR-20 from Streptomyces tsukubaensis and IR-Sip from Streptomyces ipomoeae, that allowed a comprehensive substrate screening with a photometric NADPH assay. We screened 39 carbonyl substrates combined with 17 amines as nucleophiles. Activity data from 663 combinations provided a clear picture about substrate specificity and capabilities in the reductive amination of these enzymes. Besides aliphatic aldehydes, the IREDs accepted various cyclic (C4–C8) and acyclic ketones, preferentially with methylamine. IR-Sip also accepted a range of primary and secondary amines as nucleophiles. In biocatalytic reactions, IR-Sip converted (R)-3-methylcyclohexanone with dimethylamine or pyrrolidine with high diastereoselectivity (>94–96 % de). The nucleophile acceptor spectrum depended on the carbonyl substrate employed. The conversion of well-accepted substrates could also be detected if crude lysates were employed as the enzyme source.
Synthesis of N-methyl-N-(1-methylpropyl)-1-(2-chlorophenyl)-isoquinoline-3-[11C]ca rboxamide ([11C-carbonyl]PK11195) and some analogues using [11C]carbon monoxide and 1-(2-chlorophenyl)isoquinolin-3-yl triflate
Rahman, Obaidur,Kihlberg, Tor,Langstroem, Bengt
, p. 2699 - 2703 (2007/10/03)
The benzodiazepine receptor ligand, N-methyl-N-(1-methylpropyl)-1-(2-chlorophenyl)isoquinoline-3-carboxamide (PK11195), and five structurally related analogues were 11C-labelled via a palladium-mediated carbonylation using [11C]carbon monoxide, 1-(2-chlorophenyl)isoquinolin-3-yl trifluoromethanesulfonate and various amines. The 11C-labelled products were obtained with decay-corrected radiochemical yields in the range of 10-55% and with high specific radioactivity (e.g. 200-900 GBq μmol-1). The radiochemical purity of the final products exceeded 98%. In a typical experiment starting with 3.75 GBq [11C]carbon monoxide, 0.57 GBq of LC-purified products were obtained within 35 min of the start of the carbonylation reaction. For confirmation of the labelling position, N-(1-methylethyl)-1-(2-chlorophenyl)-isoquinoline-3-(13C)carboxamide was prepared and analysed by NMR. The precursor 1-(2-chlorophenyl)isoquinolin-3-yl trifluoromethanesulfonate was synthesised in five steps starting from 2-chlorobenzophenone. The precursor N-methyl-sec-butylamine was prepared from sec-butylamine by the reaction with ethyl chloroformate followed by reduction with LiAlH4. The non-radioactive reference compounds for the analogues were synthesised from 1-(2-chlorophenyl)isoquinoline-3-carboxylic acid and the appropriate amines.
ELECTROCHEMICAL REDUCTIVE AMINATION. I. AMINATION OF ALIPHATIC KETONES BY PRIMARY AMINES
Smirnov, Yu. D.,Tomilov, A. P.
, p. 42 - 48 (2007/10/02)
The reductive amination of aliphatic ketones in aqueous solutions of primary amines was realized by an electrochemical method.The best yields of the secondary amines were obtained at lead and cadmium cathodes in an aqueous electrolytic solution at pH 11-12.Elongation and branching in the carbon chain of the radicals both of the ketone and of the primary amine lead to a reduction in the yield of the secondary amine.The yield of the secondary amine is mainly determined by the rate of the chemical reaction leading to the formation of the azomethine compound, preceding the electrochemical reduction stage.
Ion-Dipole Complexes in the Unimolecular Reactions of Isolated Organic Ions. Effect of N-Methylation on Olefin and Amine Loss from Protonated Aliphatic Amines
Bowen, Richard D.,Harrison, Alex G.,Reiner, Eric J.
, p. 1009 - 1014 (2007/10/02)
The slow unimolecular fragmentation reactions os 18 gaseous protonated aliphatic amines of general formula R1NH(1+)R2R3 (R1=Prn, Pri, Bun, Bui, Bus, or But; R2,R3=H,CH3) are reported and discussed.Two decomposition routes are observed for a metastable ions R1NH(1+)R2R3.The first involves elimination of a neutral amine, R2R3NH, and formation of a carbocation, R1(1+), via a mechanism involving an incipient cation bound to the developing amine by an ion-dipole attraction.Rearrangement of the cation, to give thermodynamically more stable isomers, is feasible in these ion-dipole complexes.Further reorganization of the complexes leads to a species in which an incipient olefin 1-H> and an amine 2R3NH> are co-ordinated to a common proton.Dissociation of these proton-bound complexes, with retention of the proton by the developing amine, results in olefin loss, which is the secondreaction undergone by metastable ions R1NH(1+)R2R3.The relative abundance of amine expulsion is greater for protonated amines containing a primary alkyl group, R1, than is the case for isomeric ions containing secondary or tertiary alkyl groups.Progressive methylation of the nitrogen atom decreases the relative abundance of amine loss from R1NH(1+)R2R3, regardless of the nature of the principal alkyl group.These two trends are explained in terms of the energetics of the intermediates and products involved in the decomposition of the protonated amines.
THE ELECTROPHILIC AMINATION OF ORGANOLITHIUMS WITH METHYLLITHIUM COMPLEXES OF N-SUBSTITUTED METHOXYAMINES
Kokko, Bruce J.,Beak, Peter
, p. 561 - 564 (2007/10/02)
Three N-alkyl methoxyamine derivatives are shown to be effective as electrophilic reagents for the conversion of organolithiums to secondary amines.
