(CF₃CO)₂O/CF₃SO₃H-mediated synthesis of 1,3-diketones from carboxylic acids and aromatic ketones

Abstract

SummaryA very simple and convenient reaction for 1,3-diketone preparation from carboxylic acids and aromatic ketones in TFAA/TfOH system is described. When the β-phenylpropionic acids were used as starting materials, they initially gave 1-indanones and then underwent further acylation with the formation of 2-(β-phenylpropionyl)-1-indanones as the main reaction products. In addition, the application of the proposed protocol allowed for the synthesis of selected polysubstituted pyrazoles in a one-pot procedure directly from acids and ketones.

1,3-Diketones. Synthesis and properties

“…The obtained results allowed us to presume that ketones can be directly subjected to acylation in the system TfOH-TFAA-CH 2 Cl 2 [24]. The acylation of alkyl aryl ketones 22 (acetophenone, benzyl methyl ketone, indanone, tetralone, 2-acetylthiophene, 2-acetylbenzofuran) with acids 23 (R = Me, i-Pr, t-BuCH 2 , 1-AdCH 2 ) gave β-diketones 24-30.…”

“…The described procedure for the pre- n = 1 (a), 2 (b), no bond (c); 39a (88%), 39b (51%), 39c (32%); 40a (72%), 40b (81%), 40c (77%). paration of β-diketones has underlain one-pot synthesis of polycyclic systems containing pyrazole fragments (see Section 3.1) [23,24].…”

“…The reaction involved self-acylation of 35 even at room temperature, which significantly complicated the isolation of 36. When acid 35 was heated in CF 3 SO 3 H/TFA [24], followed by decarboxylation in aqueous medium, 1,3-bis(diphenylphosphoryl)propan-2-one (37) was obtained in 44% yield (Scheme 10). 3-(Trifluoroacetoxy)adamantan-1-yl-substituted diketones 39a-39c were synthesized by acylation of 31 with (3-hydroxyadamantan-1-yl)acetic acid (38a) (Scheme 11).…”

“…Reactions of structurally diverse 1,3-diketones with hydrazine hydrate and substituted hydrazines lead to the formation of pyrazoles (recent data are collected in Tables 1-3 [23,24] One-pot syntheses ketones are few in number. In particular, enol trifluoromethanesulfonates derived from acetylacetone and benzoylacetone (161) (Table 1).…”

Direct Regio- and Diastereoselective Diphosphonylation of Cyclic Enamines: One-Pot Synthesis of α,α′-Bis(diphenylphosphoryl)- and α,α′-Bis(diphenylphosphorothioyl)cycloalkanones

“…6,[24][25][26] To the best of our knowledge, symmetrical ,'-bis(diphenylphosphoryl)-and ,'-bis(diphenylphosphorothioyl)-cycloalkanones have never been synthesized, but there are only two reports concerning the synthesis of acyclic analogues of ,'-bis(diphenylphosphoryl)cycloalkanones. This includes (i) the TFAA/TfOH-mediated self-acylation of diphenylphosphorylacetic acid 27 and (ii) the bromination of 3-(diphenylphosphoryl)-3-methylbutanone followed by a Michaelis-Arbuzov phosphonylation. 28 The scope of these reactions is, however, limited and only two acyclic ,'-bis(diphenylphosphoryl)ketones have been synthesized from these strategies, in lower than 40% overall yield.…”