Superelectrophilic Activation of Alkynes, Alkenes, and Allenes

DFT insights into superelectrophilic activation of α,β-unsaturated nitriles and ketones in superacids

“…9,11,[30][31][32] It is not surprising, therefore, that these and analogous species have been repeatedly proposed as key superelectrophilic 2 intermediates in the corresponding reactions with weak nucleophiles, such as benzene, deactivated aromatics and alkanes. 6,[8][9][10][11][12][13][14][15][16][17][18][19][20][22][23][24][25][26]33 On the other hand, perhaps the most widely proposed candidate for the role of a strong electrophile derived from α,β-enones in superacids is the O,O-diprotonated form 6 (Fig. 4).…”

“…undergo a specific kind of electrophilic activation upon action with strong Brønsted or Lewis acids. 1–25 This allowed involving them in a large variety of Friedel–Crafts type transformations, offering quite appealing synthetic solutions. Fig.…”

Synthesis of 3-Aryl-3-(Furan-2-yl)Propanoic Acid Derivatives, and Study of Their Antimicrobial Activity

“…Based on our research on superelectrophilic activation in organic synthesis [ 13 , 14 ] and our investigation in furan chemistry [ 15 , 16 ], we undertook this study on the synthesis of novel compounds from furfural and 5-HMF. The main goals of this work were the synthesis of 3-(furan-2-yl)propenoic acids and their esters, investigation of their reactions of with arenes under the activation by strong Brønsted (triflic acid TfOH (CF 3 SO 3 H)) and Lewis (AlCl 3 and AlBr 3 ) acids, study on the reaction cationic intermediates by NMR and DFT calculations, and study on the biological activity of the reaction products.…”

AlBr3-Promoted stereoselective anti-hydroarylation of the acetylene bond in 3-arylpropynenitriles by electron-rich arenes: synthesis of 3,3-diarylpropenenitriles

“…In TfOH, the reactions proceed further to 3-arylindanones, as products of the intramolecular aromatic acylation of the 3,3-diarylpropanenitriles by the electrophilically activated nitrile group [16,17]. Based on this study and our work on electrophilic transformations of alkynes [18][19][20], we investigated reactions of 3-arylpropynenitriles under electrophilic activation conditions (see [21] for the chemistry of superelectrophilic species). The goal of this work was to study the reactions of 3-arylpropynenitriles with arenes under the action of the strong Lewis acids, aluminum halogenides AlX 3 (X = Cl, Br) and the Brønsted superacid TfOH (CF 3 SO 3 H).…”