7780-04-3Relevant articles and documents
Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
supporting information, p. 1618 - 1629 (2021/01/25)
Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for the retention of various reducible functionalities and the compatibility of sensitive groups toward hydroboration, thereby providing a mild, chemoselective, and facile strategy to form anilines, as well as heteroaryl and aliphatic amine derivatives, with broad scope and particularly high turnover numbers (up to 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate that the CAAC ligand plays an important role in promoting polarity reversal of hydride of HBpin; it serves as an H-shuttle to facilitate deoxygenative hydroboration. The preparation of several commercially available pharmaceuticals by means of this strategy highlights its potential application in medicinal chemistry.
Preparation method of isopropanolamine
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Paragraph 0014, (2017/01/23)
A preparation method of isopropanolamine comprising the following steps: 1, weighing isopropanolamine with the mole content of 80% or more and hydrochloric acid according to a ratio of 1:1, wherein the isopropanolamine is MIPA, DIPA and TIPA; 2, adding a calculated amount of hydrochloric acid to a flask with three necks, adding a calculated amount of commercial MIPA or TIPA in batches under stirring until the pH value is 2 at below 40DEG C, precipitating crystals, continuously stirring for cooling to 0DEG C, filtering to respectively obtain MIPA.HCl or TIPA.HCl, mixing the above obtained two mother liquors, and carrying out reduced pressure dewatering to obtain DIPA.HCl; or adding the calculated amount of hydrochloric acid to the flask with three necks, adding a calculated amount of commercial DIPA in batches under stirring until the pH value is 2 at below 40DEG C, cooling to 0DEG C, filtering to obtain a filter cake to be processed, and carrying out reduced pressure distillation under 100mmHg on the obtained filtrate until no precipitate precipitates to obtain DIPA.HCl; and 3, respectively carrying out a free reaction on the MIPA.HCl, DIPA.HCl and TIPA.HCl and an equivalent amount of a methanol solution of sodium methoxide, filtering to remove salt, and carrying out reduced pressure distillation on the above obtained methanol recovered solution to respectively obtain high-quality MIPA, DIPA and TIPA with the content of 97-99%. The obtained isopropanolamine can completely substitute imported products, meets domestic needs, and has substantial benefits.
Lithiation of α-Nitrosaminoalkyl Ethers. Synthetic Equivalents of α-Primary Amino Carbanions
Saavedra, Joseph E.
, p. 2388 - 2392 (2007/10/02)
Successful experiments directed toward the C-1 alkylation and hydroxyalkylation of primary amines are reported.Primary amines are converted into their N-nitroso-N-(1-methoxyethyl) derivatives, which are subsequently lithiated and condensed with various electrophiles, denitrosated, and hydrolyzed to produce the desired compounds in good to excellent yields.
