- Preparation method O - alkyl substituted hydroxylamine salt
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The invention relates to a preparation method of N - alkyl substituted hydroxylamine salt, and belongs to fine chemical engineering. Pesticide or bulk pharmaceutical chemicals technical field. The present invention reacts with the N - alkyl of the oxime with an inorganic salt of hydroxylamine to give N - alkyl-substituted hydroxylamine salt and oxime. The invention provides an efficient and environment-friendly method for preparing N - alkyl substituted hydroxylamine salt, and simultaneously, an N - alkyl substituted hydroxylamine salt is prepared, and the oxime can be re-prepared to form N - alkylate of oxime so as to realize the material circulation. No equivalent acid is used in the reaction process. Alkali neutralization, avoided the current method to use a large amount of acid, alkali and produce inorganic salt solid waste shortcoming, environmental protection more. The preparation method is mild in reaction condition, and the defects of high pollution and high energy consumption of the traditional process are overcome. In-flight R1 , R2 What is R is as claimed in the claims and the description.
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Paragraph 0118; 0122-0123
(2021/11/14)
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- Total synthesis of (±)-gephyrotoxin by amide-selective reductive nucleophilic addition
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A chemoselective approach for the total synthesis of (±)- gephyrotoxin has been developed. The key to success was the utilization of N-methoxyamides, which enabled the direct coupling of the amide with an aldehyde and selective reductive nucleophilic addition to the amide in the presence of a variety of sensitive and electrophilic functional groups, such as a methyl ester. This chemoselective approach minimized the use of protecting-group manipulations and redox reactions, which resulted in the most concise and efficient total synthesis of (±)-gephyrotoxin described to date. Aim for selectivity: A chemoselective approach that utilizes N-methoxyamides has been developed for the total synthesis of (±)-gephyrotoxin. The N-methoxy group enabled the direct coupling of the amide with an aldehyde and amide-selective reductive allylation in the presence of a more electrophilic methyl ester, which resulted in the most concise and efficient total synthesis of (±)-gephyrotoxin described to date.
- Shirokane, Kenji,Wada, Takamasa,Yoritate, Makoto,Minamikawa, Ryo,Takayama, Nobuaki,Sato, Takaaki,Chida, Noritaka
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supporting information
p. 512 - 516
(2014/01/23)
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- Indium-assisted aluminium-based stereoselective allylation of prostereogenic α,α-disubstituted cycloalkanones and imines
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The use of a catalytic amount of InCl3in combination with Al0for the allylation of a variety of prostereogenic α,α-disubstituted (hindered) cycloalkanones, 1,2-dione-based systems and various imino systems (CN functional groups) is reported. The stereoselective InCl3-catalyzed Al-based allylation of various 2-substituted-2-carbethoxycycloalkanones gave the corresponding products with moderate to excellent diastereoselectivity. The allylation and propargylation of imines including α-imino esters using a catalytic amount of InCl3in combination with Al0gave the corresponding allylated and propargylated compounds in moderate to good yields. If γ-substituted allylic halides were added to imino compounds, low to very good diastereoselectivity was obtained. The allylation of chiral N-tert-butylsulfinyl imine systems gave the corresponding products in moderate yields with good to excellent diastereoselectivity. This journal is
- Reddy, Chennakesava,Babu, Srinivasarao Arulananda,Aslam, Nayyar Ahmad
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p. 40199 - 40213
(2014/12/10)
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- Chemoselective reductive nucleophilic addition to tertiary amides, secondary amides, and N-methoxyamides
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As the complexity of targeted molecules increases in modern organic synthesis, chemoselectivity is recognized as an important factor in the development of new methodologies. Chemoselective nucleophilic addition to amide car-bonyl centers is a challenge because classical methods require harsh reaction conditions to overcome the poor elec-trophilicity of the amide carbonyl group. We have successfully developed a reductive nucleophilic addition of mild nu-cleophiles to tertiary amides, secondary amides, and N-methoxyamides that uses the Schwartz reagent [Cp2ZrHCl]. The reaction took place in a highly chemoselective fashion in the presence of a variety of sensitive functional groups, such as methyl esters, which conventionally require protection prior to nucleophilic addition. The reaction will be applicable to the concise synthesis of complex natural alkaloids from readily available amide groups.
- Nakajima, Minami,Oda, Yukiko,Wada, Takamasa,Minamikawa, Ryo,Shirokane, Kenji,Sato, Takaaki,Chida, Noritaka
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supporting information
p. 17565 - 17571
(2015/02/19)
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- Palladium-catalyzed aerobic oxidation of amines
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Pd-Catalyzed aerobic oxidation of different amines was systematically examined for the first time. A PdCl2/PPh3 system was successfully developed to catalyze the aerobic oxidation of several types of amines including Ar-CH2NHPh, Ar-CH2NHOMe, and Ar-CH2NHMs with high yields. Theoretical studies showed a remarkable difference in the energy barriers of β-hydride elimination between an alcohol and various amines.
- Wang, Jia-Rui,Fu, Yao,Zhang, Bei-Bei,Cui, Xin,Liu, Lei,Guo, Qing-Xiang
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p. 8293 - 8297
(2007/10/03)
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- Oxidative conversion of aldoximes into carboxylic acid esters
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Aromatic and aliphatic aldoximes or their O-methyl ethers can be efficiently converted into the corresponding carboxylic acid esters by treatment with an alcoholic solution of 30% hydrogen peroxide in the presence of catalytic amounts of 2-nitrobenzeneseleninic acid. Primary alcohols give excellent to good yields, secondary ones - good to moderate, but with tertiary alcohols no esterification is observed.
- Said,Skarzewski,Mlochowski
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p. 1851 - 1862
(2007/10/02)
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