Acylation of Alcohols, Part 4: with Carboxylic Acids скачать в хорошем качестве

Acylation of Alcohols, Part 4: with Carboxylic Acids

This video is about the direct acid-catalyzed condensation of carboxylic acids with alcohols for the preparation of carboxylic esters. This is one of the most relevant strategies for preparing low molecular weight esters on a large scale, but is not always applicable to structurally more complex starting materials. This reaction is always acid-catalyzed because carboxyl groups or deprotonated carboxylates are not electrophilic enough to react with alcohols. And if no stoichiometric amount of some water-absorbing reagent is used, this reaction is an equilibration, and either the resulting water must be continuously removed by distillation, or a large excess of alcohol or acid must be used. Further examples: Tetrahedron 2021, 81, 131873 (lipase); Org. Syn. 2020, 97, 139 (H2SO4); Org. Proc. Res. Dev. 2020, 24, 599-603 (TsOH); Tetrahedron 2019, 75, 2877-2882 (alkynes); ACS Sust. Chem. Eng. 2019, 7, 15874-15883 (WO3-H3PO4); Org. Proc. Res. Dev. 2017, 21, 1088-1090 (H2SO4); EP 2465841 (2016, aq HCl); Org. Proc. Res. Dev. 2012, 16, 1646-1651 (no catalyst); 1098-1101 (lipase); 2010, 14, 48-57 (lipase); Org. Syn. 2009, 86, 194 (TsOH); Org. Proc. Res. Dev. 2005, 9, 743-748 (ionic liquid); 599-607 (ion-exchange resin); 288-293 (ion-exchange resin); US 5302747 (1994, no catalyst); Org. Syn. 1990, 69, 10 (H2SO4); 1983, 61, 77 (MeSO3H); 1976, 55, 77 (H2SO4); 1958, 38, 55 (H2SO4); 1956, 36, 44 (H2SO4); 1955, 35, 59 (HCl); 1949, 29, 44 (HCl); 33 (TsOH); 1943, 23, 37 (H2SO4); 1942, 22, 82 (HCl); 1933, 13, 42 (HCl).