A convenient and practical synthesis of β-diketones bearing linear perfluorinated alkyl groups and a 2-thienyl moiety

• Ilya V. Taydakov,
• Yuliya M. Kreshchenova and
• Ekaterina P. Dolotova

Beilstein J. Org. Chem. 2018, 14, 3106–3111, doi:10.3762/bjoc.14.290

• condensation; copper chelate; β-diketones; perfluorinated esters; thiophene; Introduction Classical β-diketones have been studied for more than a century, and no doubt, they are the most popular O,O-ligands in the coordination chemistry of d- and f-elements [1][2][3]. These compounds are widely used as

• ]. This compound was first obtained by Reid and Calvin in 1950 [15] by Claisen condensation of 2-acetylthiophene and ethyl trifluoroacetate in the presence of NaOEt in Et2O (Scheme 1). The purification procedure was laborious and included copper chelate precipitation and its subsequent acid decomposition

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

• Tor E. Kristensen

Beilstein J. Org. Chem. 2015, 11, 446–468, doi:10.3762/bjoc.11.51

• mentioned this O-acetylation method in particular, as part of their investigations of poly-L-tyrosine, but they rejected it in favour of copper chelate protection since the acidic acylation gave the product in salt form [14]. They also evaluated the method of Sakami and Toennies, but likewise rejected it

• on O-acylations of hydroxyproline in MeSO3H (Scheme 6) were known to the authors [20][34][46]. Use of copper chelate protective chemistry had failed, as had the first O-acylation attempts using acryloyl chloride in HCl–acrylic acid–H2O, in analogy with the known O-acetylation method of Wilchek and