6-(Trifluoromethyl)-2H-pyran-2-ones: Promising CF3-bearing conjugated cyclic diene and electrophilic building-blocks

Diels–Alder Reaction in the Synthesis of Fluorinated (Hetero)Aromatic Compounds

“…6‐Trifluoromethyl‐2‐pyrones are the most frequently studied fluorinated 2‐pyrones. They were effectively applied to synthesize diverse CF 3 ‐containing molecules including aromatic compounds through Diels–Alder strategy (Scheme ) . In the first example described by Martin et al pyrone 23 was synthesized from CF 3 CCl 3 and diester 21 in 3 steps and involved in Diels–Alder reaction with different acetylenes affording aromatic products 24 .…”

“…They were effectively applied to synthesize diverse CF 3 -containing molecules including aromatic compounds through Diels-Alder strategy (Scheme 10). [16] In the first example described by Martin et al [17] pyrone 23 was synthesized from CF 3 CCl 3 and diester 21 in 3 steps and involved in Diels-Alder reaction with different acetylenes affording aromatic products 24. While the reaction with 1-diethylamino-1propyne takes place at 0°C, reactions with acetylene, DMAD and phenyl acetylene required temperatures of 140 to 200°C.…”

Chemistry of fluoroalkyl cyanides

“…[1][2][3][4] An electron-withdrawing R F group bonded to a carbon atom that belongs to a double or triple bond, or a conjugated system, significantly increases the electrophilic, dienophilic and dienic (in the case of a conjugated system) properties of the molecule. 5,6 Fluoroalkyl cyanides (R F -cyanides, R F -nitriles) are a group of unique compounds, where a fluoroalkyl group is bonded to the highly polarized C≡N group. This fact dramatically increases the electrophilic as well as dienophilic properties of the C≡N group.…”

β‐Trifluoromethyl α,β‐unsaturated Ketones: Efficient Building Blocks for Diverse Trifluoromethylated Molecules

“…[3] Taking into account the importance of trifluoromethyl group, a tremendous effort has been paid towards the development of synthetic methodology for the introduction of trifluoromethyl group into diverse organic frameworks. [4][5][6][7][8][9][10][11][12][13][14] Due to the advancement of synthetic organic chemistry, the CF 3 substituted molecules can be accessed through two major routes: (i) Direct trifluoromethylation reaction using various reagents, [4] and (ii) using the prefunctionalized CF 3 group containing building blocks. [5] For the first route there have been various reviews that deal with different types of trifluoromethyl reagents based on their electronic nature such as radical, [6] electrophilic, [7] or nucleophilic [8] or the types of strategy used for the construction of trifluoromethylated molecules using these reagents.…”

“…[4,[6][7][8] The reviews on second route have also been reported with individual fluorinated building blocks. [9] For trifluoromethyl group, only few building blocks have been explored, for example aryl trifluoromethyl ketones, [10] trifluoroacetoacetate, [11] trifluoromethylated internal alkynes, [12] α,β-unsaturated trifluoromethylketones, [13] etc. To this end, Billard has reported a short review on β-trifluoromethyl-α,β-unsaturated carbonyl compound, mainly the ester counterpart in 2006, [14a] however an important building block remained unaddressed, i.e β-trifluoromethyl-α,β-unsaturated ketones, which has tremendously gained attention in the recent years to the organic chemists due to its availability and versatility of reactions it undergoes.…”