- Nickel-Catalyzed Selective Reduction of Carboxylic Acids to Aldehydes
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The direct reduction of carboxylic acids to aldehydes is a fundamental transformation in organic synthesis. The combination of an air-stable Ni precatalyst, dimethyl dicarbonate as an activator, and silane reductant effects this reduction for a wide variety of substrates, including pharmaceutically relevant structures, in good yields and with no overreduction to alcohols. Moreover, this methodology is scalable, allows access to deuterated aldehydes, and is also compatible with one-pot utilization of the aldehyde products.
- Iosub, Andrei V.,Morav?ík, ?tefan,Wallentin, Carl-Johan,Bergman, Joakim
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supporting information
p. 7804 - 7808
(2019/10/14)
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- Unfunctionalized, α-epimerizable nonracemic ketones and aldehydes can be accessed by crystallization-induced dynamic resolution of imines
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This paper describes an operationally simple deracemization process of aldehydes and ketones. This new crystallization-induced dynamic resolution (CIDR) protocol allows for nearly complete conversion of the racemic mixture into one enantiomer. Crystallization of imines derived from racemic ketones or aldehydes 1 and trans-(1R,2R)-1-amino-6-nitroindan-2-ol (2) afforded diastereomerically pure, crystalline imines 3. Biphasic hydrolysis of 3 then affords recovered 2 and enantiomerically enriched 1 in high yield and er (substrate, yield/ee: 2-methylcyclohexanone, 97%/92; 2-ethylhexanal, 94%/98; 2-methylcyclopentanone, 94%/98; 2-cyclohexylcyclohexanone, ND/98; 3-methyl-2-pentanone, ND/76). The scope, limitations, and industrial perspective of this process are discussed. This highly effective CIDR process is likely due to π-stacking of 2 and a hydrogen bonding of the imine with the free hydroxyl of 2 in the solid state. Copyright
- Kosmrlj, Janez,Weigel, Leland O.,Evans, David A.,Downey, C. Wade,Wu, Jimmy
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p. 3208 - 3209
(2007/10/03)
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- Quantitative RP-HPLC determination of some aldehydes and hydroxyaldehydes as their 2,4-dinitrophenylhydrazone derivatives
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A high-performance liquid chromatographic (HPLC) method is described for the quantitative determination of some aliphatic aldehydes and β- hydroxyaldehydes as their 2,4-dinitrophenylhydrazone derivatives. A method is described for the preparation of deriv
- Koivusalmi,Haatainen,Root
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