Xi:Irritant;106-52-5Relevant articles and documents
Specificities of the enzymes of N-alkyltropane biosynthesis in Brugmansia and Datura
Boswell, Henry D.,Draì?ger, Birgit,McLauchlan, W. Russell,Portsteffen, Andreas,Robins, David J.,Robins, Richard J.,Walton, Nicholas J.
, p. 871 - 878 (1999)
The enzymes N-methylputrescine oxidase (MPO), the tropine-forming tropinone reductase (TRI), the pseudotropine-forming tropinone reductase (TRII), the tropine:acyl-CoA transferase (TAT) and the pseudotropine:acyl-CoA transferase (PAT) extracted from transformed root cultures of Datura stramonium and a Brugmansia candida x aurea hybrid were tested for their ability to accept a range of alternative substrates. MPO activity was tested with N-alkylputrescines and N-alkylcadaverines as substrates. TRI and TRII reduction was tested against a series of N-alkylnortropinones, N- alkylnorpelletierines and structurally related ketones as substrates. TAT and PAT esterification tests used a series of N-substituted tropines, pseudotropines, pelletierinols and pseudopelletierinols as substrates to assess the formation of their respective acetyl and tigloyl esters. The results generally show that these enzymes will accept alien substrates to varying degrees. Such studies may shed some light on the overall topology of the active sites of the enzymes concerned.
Conformation of N-methyl-4-piperidyl 2,4-dinitrobenzoate
Andrau, Laura,White, Jonathan
, p. o60-o61 (2003)
The crystal structure of N-methyl-4-piperidyl 2,4-dinitro-benzoate. C13H15N3O6 (I), at 130 (2) K reveals that, in the solid state, the molecule exists in the equatorial conformation, (leq). Thus, the through-bond interaction present in the axial conformation, (lax), is not strong enough to overcome the syn-diaxial interactions between the axial methyl substituent and the axial H atoms on the two piperidyl ring C atoms either side of the ester-linked ring C atom. The carboxylate group in (I) is orthogonal to the aromatic ring, in contrast with other 2,4-dinitrobenzoates, which are coplanar. The piperidyl-ester C-O bond distance is 1.467 (3) A, which is actually shorter than other equatorial cyclohexyl-ester C-O distances. This shorter piperidyl-ester C-O bond distance is due to the reduced electron demand of the orthogonal ester group.
Hydrogenation of hindered ketones catalyzed by a silica-supported compact phosphine-Rh system
Kawamorita, Soichiro,Hamasaka, Go,Ohmiya, Hirohisa,Hara, Kenji,Fukuoka, Atsushi,Sawamura, Masaya
, p. 4697 - 4700 (2008)
(Chemical Equation Presented) A heterogeneous mono(phosphine)-Rh catalyst system silica-SMAP-Rh(OMe)(cod), where silica-SMAP stands for a caged, compact trialkylphosphine (SMAP) supported on silica gel, showed broad applicability toward the hydrogenation of hindered ketones. Doubly α-branched ketones such as diisopropyl ketone was hydrogenated under nearly atmospheric conditions. Di-tert-butyl ketone could be hydrogenated under more forcing conditions.
Discovery of New Carbonyl Reductases Using Functional Metagenomics and Applications in Biocatalysis
Newgas, Sophie A.,Jeffries, Jack W. E.,Moody, Thomas S.,Ward, John M.,Hailes, Helen C.
, p. 3044 - 3052 (2021)
Enzyme discovery for use in the manufacture of chemicals, requiring high stereoselectivities, continues to be an important avenue of research. Here, a sequence directed metagenomics approach is described to identify short chain carbonyl reductases. PCR from a metagenomic template generated 37 enzymes, with an average 25% sequence identity, twelve of which showed interesting activities in initial screens. Six of the most productive enzymes were then tested against a panel of 21 substrates, including bulkier substrates that have been noted as challenging in biocatalytic reductions. Two enzymes were selected for further studies with the Wieland Miescher ketone. Notably, enzyme SDR-17, when co-expressed with a co-factor recycling system produced the anti-(4aR,5S) isomer in excellent isolated yields of 89% and 99% e.e. These results demonstrate the viability of a sequence directed metagenomics approach for the identification of multiple homologous sequences with low similarity, that can yield highly stereoselective enzymes with applicability in industrial biocatalysis. (Figure presented.).
Electrochemical Reductive N-Methylation with CO2Enabled by a Molecular Catalyst
Rooney, Conor L.,Wu, Yueshen,Tao, Zixu,Wang, Hailiang
supporting information, p. 19983 - 19991 (2021/12/01)
The development of benign methylation reactions utilizing CO2 as a one-carbon building block would enable a more sustainable chemical industry. Electrochemical CO2 reduction has been extensively studied, but its application for reductive methylation reactions remains out of the scope of current electrocatalysis. Here, we report the first electrochemical reductive N-methylation reaction with CO2 and demonstrate its compatibility with amines, hydroxylamines, and hydrazine. Catalyzed by cobalt phthalocyanine molecules supported on carbon nanotubes, the N-methylation reaction proceeds in aqueous media via the chemical condensation of an electrophilic carbon intermediate, proposed to be adsorbed or near-electrode formaldehyde formed from the four-electron reduction of CO2, with nucleophilic nitrogenous reactants and subsequent reduction. By comparing various amines, we discover that the nucleophilicity of the amine reactant is a descriptor for the C-N coupling efficacy. We extend the scope of the reaction to be compatible with cheap and abundant nitro-compounds by developing a cascade reduction process in which CO2 and nitro-compounds are reduced concurrently to yield N-methylamines with high monomethylation selectivity via the overall transfer of 12 electrons and 12 protons.
Synthesis and biological evaluation of new N-substituted 4-(arylmethoxy)piperidines as dopamine transporter inhibitors
Lapa, Gennady B.,Lapa, Alla A.
, p. 203 - 205 (2019/04/25)
The library of new N-substituted 4-(arylmethoxy)piperidines as dopamine transporter inhibitors was designed and synthesized. H-Bond donors in piperidine ring were found to be important for reduced locomotor activity in mice. 4-[Bis(4-fluorophenyl)methoxy]piperidine has IC50 17.0 ± 1.0 nm for dopamine transporter and locomotor activity, which is lower than that for cocaine.
Bilobalide B derivative and application of bilobalide B derivative in medicine
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Paragraph 0253; 0254; 0255, (2016/10/09)
The invention relates to a new bilobalide B derivative, hydrate, solvate or pharmacy-acceptable salt of the bilobalide B derivative, and a medicine composition with the derivative, and further relates to application of the compound or the medicine composition in preparation of medicine. The medicine is used for preventing, processing, treating or relieving cardiovascular and cerebrovascular diseases of patients. The invention further relates to a preparation method of the bilobalide B derivative.
CATALYTIC HYDROGENATION USING COMPLEXES OF BASE METALS WITH TRIDENTATE LIGANDS
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Paragraph 0038; 0054, (2015/12/07)
Complexes of cobalt and nickel with tridentate ligand PNHPR are effective for hydrogenation of unsaturated compounds. Cobalt complex [(PNHPCy)Co(CH2SiMe3)]BArF4 (PNHPCy=bis[2-(dicyclohexylphosphino)ethyl]amine, BArF4=B(3,5-(CF3)2C6H3)4)) was prepared and used with hydrogen for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (25-60° C., 1-4 atm H2). Nickel complex [(PNHPCy)Ni(H)]BPh4 was used for hydrogenation of styrene and 1-octene under mild conditions. (PNPCy)Ni(H) was used for hydrogenating alkenes.
Cobalt-catalyzed transfer hydrogenation of C=O and C=N bonds
Zhang, Guoqi,Hanson, Susan K.
supporting information, p. 10151 - 10153 (2013/10/22)
An earth-abundant metal cobalt catalyst has been developed for the transfer hydrogenation of ketones, aldehydes, and imines under mild conditions. Experiments are described which provide insights into the mechanism of the transfer hydrogenation reaction. The Royal Society of Chemistry 2013.
Mild and homogeneous cobalt-catalyzed hydrogenation of C=C, C=O, and C=N bonds
Zhang, Guoqi,Scott, Brian L.,Hanson, Susan K.
supporting information, p. 12102 - 12106 (2013/01/16)
A cationic cobalt(II)-alkyl complex is an effective precatalyst for hydrogenation of alkenes, aldehydes, ketones, and imines under mild conditions (1-4 atm H2; see scheme). The catalyst shows a high functional-group tolerance across a broad range of substrates. Experiments suggest that the active catalytic species is a cobalt(II)-hydride complex. Copyright
