- Method used for reduction of tertiary amide into alcohols and/or amines
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The invention discloses a method used for reduction of tertiary amide into alcohols and/or amines. The method comprises following steps: tertiary amide, an alkali metal reagent, and a proton donor agent are added into an organic solvent for a following reaction selectively: when the proton donor agent is a raw material alcohol and/or inorganic salt aqueous solution, the reaction product is an alcohol compound and/or tertiary amine compound. The method is capable of realizing selective reduction of tertiary amide into alcohols and tertiary amine compounds, the yield is high, the suitable rangeis wide, operation is safe and simple, the adopted raw materials are cheap and easily available; no precious metal catalyst, toxic silanes, and flammable and combustible metal hydrides are adopted; notoxic by product is generated; reaction is more friendly to the environment; problems in the prior art that amide compound reducing method operation is complex, conditions are strict, and control ofproducts is difficult are solved.
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Paragraph 0227-0230
(2019/08/07)
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- Hydrosilylation of carbonyl and carboxyl groups catalysed by Mn(i) complexes bearing triazole ligands
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Manganese(i) complexes bearing triazole ligands are reported as catalysts for the hydrosilylation of carbonyl and carboxyl compounds. The desired reaction proceeds readily at 80 °C within 3 hours at catalyst loadings as low as 0.25 to 1 mol%. Hence, good to excellent yields of alcohols could be obtained for a wide range of substrates including ketones, esters, and carboxylic acids illustrating the versatility of the metal/ligand combination.
- Martínez-Ferraté, Oriol,Chatterjee, Basujit,Werlé, Christophe,Leitner, Walter
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p. 6370 - 6378
(2019/11/20)
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- Reduction and Reductive Deuteration of Tertiary Amides Mediated by Sodium Dispersions with Distinct Proton Donor-Dependent Chemoselectivity
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A practical and scalable single electron transfer reduction mediated by sodium dispersions has been developed for the reduction and reductive deuteration of tertiary amides. The chemoselectivity of this method highly depends on the nature of the proton donor. The challenging reduction via C-N bond cleavage has been achieved using Na/EtOH, affording alcohol products, while the use of Na/NaOH/H2O leads to the formation of amines via selective C-O scission. Sodium dispersions with high specific surface areas are crucial to obtain high yields and good chemoselectivity. This new method tolerates a range of tertiary amides. Moreover, the corresponding reductive deuterations mediated by Na/EtOD-d1 and Na/NaOH/D2O afford useful α,α-dideuterio alcohols and α,α-dideuterio amines with an excellent deuterium content.
- Zhang, Bin,Li, Hengzhao,Ding, Yuxuan,Yan, Yuhao,An, Jie
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p. 6006 - 6014
(2018/05/24)
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- Palladium(II)-Catalyzed Enantioselective Arylation of Unbiased Methylene C(sp3)?H Bonds Enabled by a 2-Pyridinylisopropyl Auxiliary and Chiral Phosphoric Acids
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Enantioselective functionalizations of unbiased methylene C(sp3)?H bonds of linear systems by metal insertion are intrinsically challenging and remain a largely unsolved problem. Herein, we report a palladium(II)-catalyzed enantioselective arylation of unbiased methylene β-C(sp3)?H bonds enabled by the combination of a strongly coordinating bidentate PIP auxiliary with a monodentate chiral phosphoric acid (CPA). The synergistic effect between the PIP auxiliary and the non-C2-symmetric CPA is crucial for effective stereocontrol. A broad range of aliphatic carboxylic acids and aryl bromides can be used, providing β-arylated aliphatic carboxylic acid derivatives in high yields (up to 96 %) with good enantioselectivities (up to 95:5 e.r.). Notably, this reaction also represents the first palladium(II)-catalyzed enantioselective C?H activation with less reactive and cost-effective aryl bromides as the arylating reagents. Mechanistic studies suggest that a single CPA is involved in the stereodetermining C?H palladation step.
- Yan, Sheng-Yi,Han, Ye-Qiang,Yao, Qi-Jun,Nie, Xing-Liang,Liu, Lei,Shi, Bing-Feng
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supporting information
p. 9093 - 9097
(2018/07/25)
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- Application of A Recyclable Pseudoephedrine Resin in Asymmetric Alkylations on Solid Phase
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A pseudoephedrine resin has been successfully employed in asymmetric alkylations on solid phase. Immobilized pseudoephedrine amides are conveniently prepared by the one-step attachment of pseudoephedrine to Merrifield resin through the hydroxyl group and subsequent acylation on nitrogen. Deprotonation and alkylation of the resin-bound amides proceeds smoothly. Ketones and alcohols are cleaved from the resin in high enantiomeric excess and moderate to good overall yield. The parallel, asymmetric solid-phase synthesis of a small library of chiral ketones and alcohols has been carried out to illustrate the utility of the approach. Finally, the pseudoephedrine resin can be conveniently recycled and utilized with no significant loss in the yield or enantiomeric excess of the products.
- Hutchison, Panee C.,Heightman, Tom D.,Procter, David J.
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p. 790 - 801
(2007/10/03)
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- Practical chemoenzymatic synthesis of a 3-pyridylethanolamino β3 adrenergic receptor agonist
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A chemoenzymatic synthesis of β3 agonist 1 suitable for large scale preparation is described. The key chiral 3-pyridylethanolamine intermediate (R)-7 was prepared via an improved Neber rearrangement and a yeast-mediated asymmetric reduction. The tetrazolone fragment of the molecule was constructed via a dipolar cycloaddition between 1-(cyclopentyl)-3-propylazide and p-chlorosulfonyl phenylisocyanate. Sulfonamide coupling of these two intermediates under Shotten-Baumann conditions, followed by a borane reduction of the amide afforded 1 in 20-32% overall yield from 3-acetylpyridine.
- Chung, John Y. L.,Ho, Guo-Jie,Chartrain, Michel,Roberge, Chris,Zhao, Dalian,Leazer, John,Farr, Roger,Robbins, Micheal,Emerson, Kateeta,Mathre, David J.,McNamara, James M.,Hughes, David L.,Grabowski, Edward J. J.,Reider, Paul J.
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p. 6739 - 6743
(2007/10/03)
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- Process for the preparation of carbinols
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Organic compounds containing a carboxylic acid or carboxylic acid anhydride group are reduced when contacted with an alkali metal borohydride and a boron trihalide in a liquid medium in which diborane is soluble in the form of a labile borane adduct. Hydrolysis of the reaction mixture then provides a useful synthesis of the corresponding carbinols. The alkali metal borohydride-boron trihalide reagent may either be preformed and reacted subsequently with an organic compound containing a carboxylic acid or anhydride group, or the alkali metal borohydride-boron trihalide reagent may be produced in the presence of an organic compound containing a carboxylic acid or anhydride group. This development makes it possible to synthesize a wide variety of carbinols which are valuable and useful intermediates in organic synthesis.
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