- Selective Methylation of Amides, N-Heterocycles, Thiols, and Alcohols with Tetramethylammonium Fluoride
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We herein disclose the use of tetramethylammonium fluoride (TMAF) as a direct and selective methylating agent of a variety of amides, indoles, pyrroles, imidazoles, alcohols, and thiols. The method is characterized by operational simplicity, wide scope, and ease of purification. Our computational studies suggest a concerted methylation-deprotonation as the preferred reaction pathway.
- Cheng, Hong-Gang,Pu, Maoping,Kundu, Gourab,Schoenebeck, Franziska
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supporting information
p. 331 - 334
(2019/12/30)
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- Aerobic Oxidation of Cyclic Amines to Lactams Catalyzed by Ceria-Supported Nanogold
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Abstract: The oxidative transformation of cyclic amines to lactams, which are important chemical feedstocks, is efficiently catalyzed by CeO2-supported gold nanoparticles (Au/CeO2) and Aerosil 200 in the presence of an atmosphere of O2. The complete conversion of pyrrolidine was achieved in 6.5?h at 160 °C, affording a 97 % yield of the lactam product 2-pyrrolidone (γ-butyrolactam), while 2-piperidone (δ-valerolactam) was synthesized from piperidine (83 % yield) in 2.5?h. Caprolactam, the precursor to the commercially important nylon-6, was obtained from hexamethyleneimine in 37 % yield in 3?h. During the oxidation of pyrrolidine, two transient species, 5-(pyrrolidin-1-yl)-3,4-dihydro-2H-pyrrole (amidine-5) and 4-amino-1-(pyrrolidin-1-yl)butan-1-one, were observed. Both of these compounds were oxidized to 2-pyrrolidone under catalytic conditions, indicating their role as intermediates in the reaction pathway. In addition to the reactions of cyclic secondary amines, Au/CeO2 also efficiently catalyzes the oxidation of N-methyl cyclic tertiary amines to the corresponding lactams at 80 and 100 °C. Graphical Abstract: [Figure not available: see fulltext.]
- Dairo, Taiwo O.,Nelson, Nicholas C.,Slowing, Igor I.,Angelici, Robert J.,Woo, L. Keith
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p. 2278 - 2291
(2016/11/09)
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- Supported Gold Nanoparticles for Efficient α-Oxygenation of Secondary and Tertiary Amines into Amides
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Although the α-oxygenation of amines is a highly attractive method for the synthesis of amides, efficient catalysts suited to a wide range of secondary and tertiary alkyl amines using O2as the terminal oxidant have no precedent. This report describes a novel, green α-oxygenation of a wide range of linear and cyclic secondary and tertiary amines mediated by gold nanoparticles supported on alumina (Au/Al2O3). The observed catalysis was truly heterogeneous, and the catalyst could be reused. The present α-oxygenation utilizes O2as the terminal oxidant and water as the oxygen atom source of amides. The method generates water as the only theoretical by-product, which highlights the environmentally benign nature of the present reaction. Additionally, the present α-oxygenation provides a convenient method for the synthesis of18O-labeled amides using H218O as the oxygen source.
- Jin, Xiongjie,Kataoka, Kengo,Yatabe, Takafumi,Yamaguchi, Kazuya,Mizuno, Noritaka
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supporting information
p. 7212 - 7217
(2016/07/06)
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- Amino-alcohol cyclization: Selective synthesis of lactams and cyclic amines from amino-alcohols
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By employing an amination catalyst, previously used in the direct synthesis of amines from alcohol with ammonia, n-amino-alcohols could be selectively cyclized to either the amide or the amine. By the addition of water, the amine could be produced as the major product whereas adding a sacrificial ketone as a hydrogen acceptor resulted in the amide as the major product. Without an additive a mixture of both the amine and the amide was observed. N-substituted amino-alcohols solely gave cyclic amines under these conditions. From 2-(n-alkanol) anilines the cyclic amines were produced, where the n-propanol derivative selectively formed quinoline as the major product.
- Pingen, Dennis,Vogt, Dieter
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- Asymmetric synthesis and evaluation of α-quaternary chiral lactam derivatives as novel anticancer agents
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Asymmetric synthesis of α-quaternary chiral lactam derivatives as novel anticancer agents and evaluation of their cytotoxic potentials and spectrums are reported. Among the developed lactam derivatives, the most active new compounds (S)-4m and (S)-4n synthesized via asymmetric phase-transfer catalytic alkylation in very high optical yields (98 % ee) show promising in vitro anticancer activities with low micromolar IC50 values against colon, uterus, lung, and breast human cancer cells.
- Lee, Hwanhyuk,Hwang, Su Jung,Jung, Jisung,Hong, Suckchang,Lee, Myungmo,Park, Hyeung-Geun,Lee, Hyo-Jong,Park, Yohan
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p. 1264 - 1270
(2015/10/05)
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- Overcoming product inhibition in catalysis of the intramolecular Schmidt reaction
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A method for carrying out the intramolecular Schmidt reaction of alkyl azides and ketones using a substoichiometric amount of catalyst is reported. Following extensive screening, the use of the strong hydrogen-bond-donating solvent hexafluoro-2-propanol was found to be consistent with low catalyst loadings, which ranged from 2.5 mol % for favorable substrates to 25 mol % for more difficult cases. Reaction optimization, broad substrate scope, and preliminary mechanistic studies of this improved version of the reaction are described.
- Motiwala, Hashim F.,Fehl, Charlie,Li, Sze-Wan,Hirt, Erin,Porubsky, Patrick,Aube, Jeffrey
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supporting information
p. 9000 - 9009
(2013/07/26)
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- Lightening Agents and/or Dyes that Contain Aldehyde(s)
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Agents for dyeing and/or lightening keratin fibers, in particular human hair, containing, relative to the weight thereof, 0.001 to 15 wt. % of at least one aldehyde of the formula (I): wherein X represents —CH(R2)—SO2—Y—R1, —CR3R4R5, or wherein Y represents —CH(CHO)— or —CH2— or a chemical bond, and wherein each of R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 independently represents —H or —CN or —F or —Cl or —Br or —I or —CHO or —NH2 or —NO2 or —CF3 or —CCl3 or —CF2CF3 or —CCl2CCl3 or an optionally substituted (C1-C6) alkyl group or a hydroxyalkyl group or a polyhydroxyalkyl group or an optionally substituted (C1-C6) alkylene group, and wherein the agent contains no oxidation dye precursors of developer and coupler type.
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- A novel and efficient oxidation of 1,2-amino alcohols to dialkylamides
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The oxidation of 1,2-amino alcohols and α-amino ketones can be efficiently performed using potassium hydroxide in the presence of air. This novel procedure affords carboxylic derivatives in excellent yields and high purity.
- García-Valverde, María,Pedrosa, Rafael,Vicente, Martina
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p. 2092 - 2094
(2007/10/03)
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- Process for the selective alkylation of betaxolol intermediates
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The present invention relates to a process for the selective alkylation of intermediates of betaxolol.
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P-phenyl C-aminophosphaalkenes 1 react with p-chlorobenzonitrile oxides at -20°C leading to 1,2,4-oxazaphospholines 2, which are characterized by NMR and decompose slowly at room temperature. An experimental and theoretical study of their thermal evolution shows that the most probable mechanism involves the formation of an azaphospholine such as 10 which is unstable generating a phenyl phosphinidene. The latter polymerize quickly.
- Rahmouni, Mustapha,Ko, Yeung Yat Cheng Yeung Lam,Carrie, Robert,Tonnard, Francois
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p. 12625 - 12632
(2007/10/02)
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- N-(DIMETHYLALKOXYSILYLMETHYL)- AND N-(DIMETHYLARYLOXYSILYLMETHYL)LACTAMS
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A comparison is made of conditions and preparative possibilities of synthesizing Si-substituted N-(dimethylsilylmethyl)lactams with oxygen-containing substituents (alkoxides, aryloxides, benzoates, and triflates) by several methods: by reactions of N-(dimethylchlorosilylmethyl)lactams with sodium alkoxides and with alcohols in the presence of triethylamine, by exchange reactions with trimethylsilyl derivatives of alcohols, phenols, benzoic and trifluoromethylsulfonic acids, and also by a one-pot technique using lactam, dimethylchloromethylchlorosilane, and triethylamine with subsequent addition to the reaction mixture of the alcohol and triethylamine. In the reaction of N-(dimethylchlorosilylmethyl)lactams with sodium alkoxides, concurrently with the replacement of halogen by an alkoxy group the Si-C bond is split to form N-methyllactams, which can also be prepared by the reaction of the initial chlorides with potassium hydroxide. According to IR spectroscopy, intramolecular O->Si coordination is observed in aryloxy-, benzoyloxy-, and trifluoromethylsulfonyloxy derivatives of N-(dimethylsilylmethyl)lactams, whereas the corresponding alkoxy derivatives lack this interaction. The structure of 1-(dimethylsilylmethyl)-2-pyrrolidone phenoxide and benzoate, 1-(dimethylpentafluorophenoxysilylmethyl)perhydro-2-azepinone, and 1-(dimethyltrifluoromethylsulfonyloxymethyl)-2-piperidone was studied by x-ray structural analysis. The lengths of the axial (C=)O->Si and Si-O bonds are, respectively, 2.367 and 1.711(2) Angstroem for the first, 2.228 and 1.711(2) Angstroem for the second, 2.078 and 1.787(2) Angstroem for the third, and 1.753 and 2.785(2) Angstroem for the fourth compound. Variations in the bond lengths are due to the properties of the Si-substituent and to the size of the lactam rings. The ease of formation of the Si-substituted N-(dimethylsilylmethyl)lactams with oxygen-containing substituents via the exchange reaction of N-(dimethylchloromethyl)lactams with the corresponding trimethylsiloxy derivatives correlates with the strength of the silicon-oxygen coordination in the reaction products.
- Artamkina, O. B.,Kramarova, E. P.,Shipov, A. G.,Baukov, Yu. I.,Macharashvili, A. A.,et al.
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p. 1590 - 1597
(2007/10/02)
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- Enzymatic formation of lactams in organic solvents
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Porcine pancreatic lipase in organic solvents catalyses the intramolecular cyclisation of aminoesters and the formation of macrocyclic bislactams from diesters and diamines.
- Gutman, Arie L.,Meyer, Elazar,Yue, Xu,Abell, Chris
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p. 3943 - 3946
(2007/10/02)
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- A simple, one-flask transformation of ketones to N-methyl lactams
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A one-flask conversion of cyclic ketones to N-methyl lactams is described. Reaction of the ketone with triethylorthoformate generates an acetal which is reacted in situ with N-(((p-nitrobenzene)sulfonyl)oxy methylamine 2a(CH3NH-OSO2C6H4NO2). Dealkylation of the resulting O-ethyl imidate with sodium iodide gives the lactam. A variety of lactams, including macrocyclic lactams, are produced simply and in good yields.
- Hoffman, Robert V.,Salvador, James M.
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p. 2429 - 2432
(2007/10/02)
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- New 5-nitroimidazoles bearing lactame nucleus: Synthesis and antibacterial properties
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New 5-nitroimidazoles bearing a trisubstituted ethylenic double bond in position 2 were prepared by reacting various 1-alkyl-2-chloromethyl-5-nitroimidazole with 3-nitrolactam anions by S(RN)1 mechanism in phase-transfer catalysis conditions. These compounds showed in vitro and in vivo antianaerobic activity which was clearly greater than that of metronidazole. Structure-activity relationships have been discussed.
- Jentzer,Vanelle,Crozet,Maldonado,Barreau
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p. 687 - 697
(2007/10/02)
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- Cyclic amides as medicaments
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This invention provides a series of novel cyclic amides of formula I in which the group >Z--Y--XC=CH--NN-CH=CHC=N--NN--N=C and the other radicals have the meanings defined in the following specification. The compounds of formula I are leukotriene antagonists. The invention also provides pharmaceutically acceptable salts of the formula I compounds; pharmaceutical compositions containing the formula I compound, or their salts, for use in the treatment of, for example, allergic or inflammatory diseases, or endotoxic or traumatic shock conditions; and processs for the manufacture of the formula I compounds, as well as intermediates for use in such manufacture.
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- An alternative efficient method for transformation of thiocarbonyl to carbonyl group using trifluoroacetic anhydride
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A simple and efficient procedure for the rapid and mild conversion of thiocarbonyls to carbonyls in high yields is described.
- Masuda, Ryoichi,Hojo, Masaru,Ichi, Tadaaki,Sasano, Shigetoshi,Kobayashi, Tatsuya,Kuroda, Chihiro
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p. 1195 - 1198
(2007/10/02)
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- Preparation of bidentate ligands
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A process is disclosed for preparing bidentate ligands of the formula: wherein:, each of Ar, R?, R§ and Y are specifically defined species;, the x bonds and the y bonds are attached to adjacent carbon atoms on the ring structures; and, n is a whole number in the range of 0-4 where Ar is phenyl: 0-6 where Ar is naphthyl: and 0-8 where Ar is phenanthryl or anthracenyl. The invention process comprises a. reductively coupling an ortho-substituted aromatic moiety to produce a biphenyl compound; b. contacting the biphenyl compound produced in Step (a) with an anion having the structure: wherein Y, Y? and R? are specifically defined species;, under conditions appropriate to form said bidentate ligand or the dioxide precursor thereof; and c. optionally reducing the intermediate product when the oxy-anion, is employed as the anion in Step (b).
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- Cyclic Allylamine-Enamine Systems. Part 8. Isomerisation Using Rhodium Complexes. 3-Aminoalkylidene-3H-indoles. Part 5. 6,7-Dihydroindoloquinolizine and 1,2,3,4,6,7-Hexahydroindoloquinolizine
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The use of rhodium-complex catalysis for cyclic allylamine --> cyclic enamine isomerisation is described.Indoloquinolizines are produced using this methodology and also via 3-amino-3H-indole intermediates.N-alkylation of N-silylated amides is described.
- Salas, Marisa,Al-Khawaja, Ibtisam K.,Thomas, Michelle J.,Joule, John A.
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p. 1666 - 1675
(2007/10/02)
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- Ti(O-i-Pr)4 MEDIATED LACTAMIZATIONS
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Ti(O-i-Pr)4 promotes the formation of 5- and 6-membered lactams from primary and secondary ω-amino acids, giving the lactams in good yield (75-93percent).
- Mader, Mary,Helquist, Paul
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p. 3049 - 3052
(2007/10/02)
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- HYPERVALENT IODINE OXIDATION OF AMINES USING IODOSOBENZENE: SYNTHESIS OF NITRILES, KETONES AND LACTAMS
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Primary aliphatic amines on oxidation with iodosobenzene in CH2Cl2 or H2O yield the corresponding nitriles, while primary cycloalkylamines give the corresponding cyclic ketones.Lactams are obtained by the oxidation of cyclic amines. (S)(-) Nicotine (15) is oxidized to (+/-)-cotinine (16).The intermediary imine involved in these processes was trapped in the case of piperidine as the α-aminonitrile.
- Moriarty, Robert M.,Vaid, Radhe K.,Duncan, Michael P.,Ochiai, Masahito,Inenaga, Minako,Nagao, Yoshimitsu
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p. 6913 - 6916
(2007/10/02)
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- PREPARATION OF LACTAMS VIA OXIDATION OF CYCLIC, TERTIARY AND SECONDARY AMINES WITH Hg(II)-EDTA COMPLEX IN ALKALINE MEDIUM
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Oxidation of N-alkylpiperidines and other cyclic, tertiary amines with Hg(II)-EDTA complex in basic solution yields lactams, similar oxidation of N-hydroxypiperidines gives hydroxamic acids (presumably via nitrones) and oxidation of N-unsubstituted piperidines affords lactams, probably via 1-piperidine trimers.
- Wenkert, Ernest,Angell, E. Charles
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p. 1331 - 1338
(2007/10/02)
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- Comparison of Dehydrogenations with Mercuric Acetate and Disodium Mercuric EDTA
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Dehydrogenations of 1-methylpiperidine with mercuric acetate and disodium mercuric edta show principally a similar mechanistic procedure, but yield - especially from the different pH in the modifications - various products, namely iminium compound and lactam, respectively.
- Moehrle, H.,Class, M.
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p. 384 - 388
(2007/10/02)
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- Facile Reduction of Pyridines with Nickel-Aluminum Alloy
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Nickel-aluminum alloy in dilute base can be used to reduce a variety of pyridines, quinolines, and isoquinoline to the corresponding piperidines, 1,2,3,4-tetrahydroquinolines, and 1,2,3,4-tetrahydroisoquinoline in good yield.The reaction is simple to perform, and high temperatures, high pressures, or hydrogen atmospheres are not required.The reaction is accelerated by substituents in the 2-position and by electron-withdrawing groups in the 3- and 4-positions while electron-supplying groups in the 3- and 4-positions retard the reaction.The major product isolated from the reduction of 2-phenylpyridine was 2-cyclohexylpiperidine hydrochloride.With isoniazid (1) and iproniazid (4) the pyridine ring is hydrogenated before the hydrazine is cleaved.
- Lunn, George,Sansone, Eric B.
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p. 513 - 517
(2007/10/02)
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- Hydrogen Peroxide Oxidation of α-(N,N-Dialkyl)aminoketones
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α-(N,N-Dialkyl)aminoketones are fragmented oxidatively by hydrogen peroxide, leading to carboxylic acids and products derived from iminium intermediates.
- Wenkert, David,Eliasson, K. Margareta,Rudisill, Duane
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p. 392 - 393
(2007/10/02)
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