Recent advances in the chemistry of α,β-unsaturated trifluoromethylketones

Succinic acid dihydrazide: a convenient N,N-double block for the synthesis of symmetrical and non-symmetrical succinyl-bis[5-trifluoro(chloro)methyl-1H-pyrazoles]

“…Since the 1970s, according to previous publications, [20][21][22][23] research groups have reported the systematic synthesis of 4-substituted 4-alkoxy-1,1,1-trihaloalk-3-en-2-ones (1) from the trihaloacetylation reaction of the respective enolethers (1a, 1b) or acetals (1c-i) with trifluoracetic anhydride or trichloroacetyl chloride, respectively.…”

“…Thus, 4-alkoxy-4-(alkyl/aryl/heteroaryl)-1,1,1-trifluoro(chloro)alk-3-en-2-ones are versatile precursors for the heterocyclic synthesis and direct construction of this type of heterocycles. [20][21][22][23] In this context and in an attempt to develop synthetic methods to obtain acyl spacer heterocycles and new fluorinated molecules, herein we report a practical and regioselective methodology for the preparation of a series of 1,4-bis …”

Regiospecific synthesis of new fatty N-acyl trihalomethylated pyrazoline derivatives from fatty acid methyl esters (FAMEs)

“…Among the most convenient of these methods is the use of starting materials containing halogens, including halogenated 1,3-dieletrophiles in the form of trihalomethylated β-diketones and trihalomethylated α-β-unsaturated ketones (as 4-alkoxy-1,1,1-trihalo-3-alken-2-ones), which are regiospecific synthons for 5-trihalomethyl-1H-pyrazoles and for a variety of halomethyl-substituted heterocyclic compounds. 10,11 The main synthetic method for preparing pyrazole involves [3 + 2] cyclization, as in the classical β-diketone with hydrazines. 12,13 Similarly, the introduction of fatty chains into organic molecules also can produce important changes in their chemical and physical properties.…”

2-methyl-7-substituted pyrazolo[1,5-a]pyrimidines: highly regioselective synthesis and bromination

“…15 The most convenient method to construct trihalogenated compounds is to use halogen-containing building blocks as starting reagents. 16,17 Our research group developed a general procedure for preparing β-alkoxyvinyl trihalomethyl ketones by acylation of enol ethers and acetals using 2-Methyl-7-Substituted Pyrazolo[1,5-a]pyrimidines J. Braz. Chem.…”

“…15 The most convenient method to construct trihalogenated compounds is to use halogen-containing building blocks as starting reagents. 16,17 Our research group developed a general procedure for preparing β-alkoxyvinyl trihalomethyl ketones by acylation of enol ethers and acetals using In addition, we have exhaustively studied the versatility of the β-alkoxyvinyl trihalomethyl ketones on heterocyclic synthesis and our research have resulting in outstanding contributions to heterocyclic synthesis. 2,16 On the other hand, aminopyrazoles are known to be highly reactive heterocyclic compounds, e.g., the nucleophilic attack of C-4 of the aminopyrazoles on the carbonyl groups, 18 and the N-nucleophilic attack on aromatic aldehydes yielding aldimines, have been extensively reported.…”