Selective Esterifications of Primary Alcohols in a Water-Containing Solvent
作者:Yong Wang、Bilal A. Aleiwi、Qinghui Wang、Michio Kurosu
DOI:10.1021/ol3022337
日期:2012.9.21
Oxyma and an oxyma derivative, (2,2-dimethyl-1,3-dioxolan-4-yl)methyl 2-cyano-2-(hydroxyimino)acetate (5b), displayed a remarkable effect on selective esterifications of primary alcohols. A wide range of carboxylic acids could be esterified with primary alcohols by using EDCI, NaHCO3, and Oxyma or Oxyma derivative 5b in 5% H2O-CH3CN. Oxyma derivative 5b is particularly useful, since it could be removed after the reaction via a simple basic or an acidic aqueous workup procedure.
Fe-Catalyzed Thioesterification of Carboxylic Esters
作者:Silja Magens、Bernd Plietker
DOI:10.1002/chem.201101073
日期:2011.8.1
shelf‐stable aryl esters and thiols, a variety of carboxylic acid esters were transformed into the corresponding thioesters with no racemization of labile stereocenters (see scheme). The method was successfully applied in a native chemical‐ligation‐type peptide formation, which suggests that the thiol may act as a co‐catalyst for future 1,2‐additions of pronucleophiles to carboxylicesters.