- Metal-Free Oxidation of Primary Amines to Nitriles through Coupled Catalytic Cycles
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Synergism among several intertwined catalytic cycles allows for selective, room temperature oxidation of primary amines to the corresponding nitriles in 85-98 % isolated yield. This metal-free, scalable, operationally simple method employs a catalytic quantity of 4-acetamido-TEMPO (ACT; TEMPO=2,2,6,6-tetramethylpiperidine N-oxide) radical and the inexpensive, environmentally benign triple salt oxone as the terminal oxidant under mild conditions. Simple filtration of the reaction mixture through silica gel affords pure nitrile products.
- Lambert, Kyle M.,Bobbitt, James M.,Eldirany, Sherif A.,Kissane, Liam E.,Sheridan, Rose K.,Stempel, Zachary D.,Sternberg, Francis H.,Bailey, William F.
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supporting information
p. 5156 - 5159
(2016/04/09)
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- A Sterically Congested α-Cyanoamine as a Cyanating Reagent: Cyanation of Acetals and Orthoesters
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The cyanation of acetals and orthoesters by using a sterically congested α-cyanoamine as a cyanating reagent was investigated. The α-cyanoamine effectively facilitated cyanation in the presence of trichlorosilyl triflate to produce a variety of cyanated adducts in excellent yields. Analysis of the reaction mixture by 1H NMR spectroscopy revealed that trichlorosilyl triflate produced an oxocarbenium cation species as an intermediate.
- Kotani, Shunsuke,Sakamoto, Midori,Osakama, Kazuki,Nakajima, Makoto
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supporting information
p. 6606 - 6609
(2015/10/29)
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- NOVEL MINOR GROOVE BINDERS
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There is provided compounds of formula (I), wherein R1, R11, R12, Qa, X, Qb, Qc, A and D have meanings given in the description, or a pharmaceutically acceptable salt or solvate thereof, which compound, salt or solvate binds to the minor groove of DNA.
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Page/Page column 63-64
(2008/06/13)
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- Les dialkoxy-2,2 ethanals, synthons difonctionnels a deux carbones : preparation par acetalisation du glyoxal et quelques applications en synthese
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Known for a long time, 2,2-dialkoxy ethanals had to be prepare by rather tedious indirect pathways since monoacetalization of glyoxal was unknown.We discovered that it is possible to acetalize only one of the glyoxal functions using a great excess of alcohol, in the presence of an active enough catalyst.With careful monitoring of the reaction, 50 to 70 percent yield of monoacetals is obtained.The monoacetal is formed much quicker than the diacetal and the maximum yield is rather quickly obtained; with further elimination of water, diacetalization proceeds at the expense of the monoacetal.Depending on azeotropic compositions and boiling points, one of the following methods is used: 1.General method: 40 percent aqueous glyoxal (1 mol), alcohol (10 mol), catalyst (0.01 to 0.1 equivalent) and solvent are refluxed with azeotropic water extraction.The monitored (GC) reaction is stopped at the most favourable moment. 2.Method without solvent, convenient for unreactive alcohols, such as i-butanol: water is evaporated from glyoxal solution (1 mol); the residue, alcohol (10 mol) and catalyst are refluxed with water azeotropic extraction. 3.Method without solvent and without water azeotropic extraction: dehydrated glyoxal (1 mol) is refluxed with alcohol (10 mol) and catalyst.This method is the most convenient for methanol and ethanol.This sample and inexpensive preparation of 2,2-dialkoxy ethanals prompted us to perform syntheses of difunctional molecules otherwise only tediously accessible, since easily obtained functionalized acetals can be hydrolysed to functionalized aldehydes which constitute interesting synthons.Hydride or catalytic reduction as well as organometallic reactions lead to alcohols, further hydrolysed into 2-hydroxy aldehydes or oxidized to give way finally to α-ketoaldehydes for which this method provides a general synthetic pathway.From the oximes, prepared by classical methods, nitriles and amines can be obtained.Starting directly from the aldahydes, amines may be prepared by hydrogenation in the presence of ammonia or amines.The reaction of 2,2-dialkoxy ethanals with amides provides hydroxy and alkoxy acetal amides.The Cannizzaro reaction was also investigated; the same reactivity is displayed by formaldehyde and glyoxal monoacetals.Other reactions, among which Wittig and Wittig-Horner, are presently being studied in our laboratory.
- Stambouli, Abdelhamid,Hamedi-Sangsari, Farid,Amouroux, Roger,Chastrette, Francine,Blanc, Alain,Mattioda, Georges
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- CYANOTRIMETHYLSILANE AS A VERSATILE REAGENT FOR INTRODUCING CYANIDE FUNCTIONALITY
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Cyanotrimethylsilane adds to some α,β-unsaturated ketones in conjugate manner under the catalytic action of Lewis acids such as triethylaluminium, aluminium chloride, and SnCl2.Hydrolysis of the products gives β-cyano ketones which are identical to the hydrocyanated products of the starting enones.The title silicon reagent reacts with acetals and orthoesters under the catalytic action of SnCl2 or BF3*OEt2 affording 2-alkoxy- and 2,2-dialkoxyalkanenitriles.Application of the reaction to O-protected β-D-ribofuranoses gives selectively β-D-ribofuranosyl cyanide in excellent yield.
- Utimoto, Kiitiro,Wakabayashi, Yukio,Horiie,Takafumi,Inoue, Masaharu,Shishiyama, Yuho,et al.
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p. 967 - 974
(2007/10/02)
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- 2-ALKOXY AND 2,2-DIALKOXY NITRILES FROM ACETALS AND ORTHOESTERS --- EXCHANGE OF ALKOXY INTO CYANO GROUP BY MEANS OF CYANOTRIMETHYLSILANE
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Title transformation is accomplished by the catalytic action of SnCl2 or BF3*OEt2.Lithio derivative of 2,2-dimethoxyacetonitrile is used as synthetic equivalent of methyl lithioformate.
- Utimoto, Kiitiro,Wakabayashi, Yukio,Shishiyama, Yuho,Inoue, Masaharu,Nozaki, Hitosi
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p. 4279 - 4280
(2007/10/02)
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