This review provides an overview of several synthetic applications of methyl perfluoroalk-2-ynoates, leading to convenient preparation of many perfluoroalkylated compounds. The use of these important substrates in the synthesis of various five-, six-, and seven-membered heterocycles, cyclopentadienes, and biphenyls is described, alongside a discussion of the mechanistic aspects of these reactions.

Using air as the oxygen source, 4-carbonyl-2-perfluoroalkylquinolines were prepared in good to excellent yields, from readily available 2-alkynylanilines and methyl perfluoroalk-2-ynoates through a Cu^II-promoted sequential process that omits the isolation of the enamine intermediates. The reaction tolerates several useful functionalities including ether, ester and chloro substituents.

A practical and economical process for the synthesis of perfluoroalkylated indole compounds has been developed. The Michael addition of 2-iodo- or 2-bromoanilines to methyl perfluoroalk-2-ynoates affords N-(o-haloaryl)enamines, which subsequently undergo a copper-catalyzed annulation reaction to give 2-perfluoroalkyl-substituted indoles in good to excellent yields. This method displays excellent functional group tolerance and is carried out in one pot under mild conditions.

An efficient route to 2-perfluoroalkylated quinoline derivatives through the copper(I)-mediated coupling–cyclization of 2-aminobenzonitriles with methyl perfluoroalk-2-ynoates is described. Moderate to excellent yields have been achieved under mild conditions. The reaction mechanism is also discussed.

One-pot, two-step cyclization of o-aminophenyl ketones 1 and methyl perfluoroalk-2-ynoates 2 takes place in the presence of copper(I) as catalyst and diisopropylethylamine as base, leading to 2-perfluoroalkylated quinolines. Compared with previous methods that have been used to generate quinoline skeletons, this technique uses inexpensive copper salt as catalyst, methyl perfluoroalk-2-ynoate as fluorinated building block and proceeds smoothly under mild conditions, which makes the transformation both sustainable and practical.

(E)-4-Aryl-1,1,1-trifluoro-3-tosylbut-3-en-2-one fluorinated building blocks were prepared through a two-step process. Treatment of these (E)-4-aryl-1,1,1-trifluoro-3-tosylbut-3-en-2-ones with arsonium bromides in the presence of Cs₂CO₃ in CH₂Cl₂ at reflux resulted in highly stereoselective ring closure to provide 4-tosyl-5-trifluoromethyl-trans-2,3-dihydrofurans in good to excellent yields.

Organocatalyzed cascade reactions between cyclic β-enamino esters and α,β-unsaturated aldehydes have been developed. They provide highly substituted indolo[2,3-a]quinolizidines and benzo[a]quinolizidines in moderate to good yields and with good to excellent enantioselectivities. Both aromatic and aliphatic α,β-unsaturated aldehydes react readily with enamino esters to furnish the desired products.

In the presence of Cu(OAc)₂·H₂O, a variety of 5-trifluoromethyl-2,4-disubstituted oxazoles were easily synthesized via t-BuOOH (TBHP)/I₂-mediated tandem oxidative cyclization from readily available starting materials aryl methanamines and α-trifluoroacetyl-substituted ketones or esters under mild conditions. The mechanism was proposed.

A highly enantioselective Michael addition of cyclic 1,3-dicarbonyl compounds to β,γ-unsaturated α-keto esters catalyzed by amino acid-derived thiourea-tertiary-amine catalysts is presented. Using 5 mol% of a novel tyrosine-derived thiourea catalyst, a series of chiral coumarin derivatives were obtained in excellent yields (up to 99%) and with up to 96% ee under very mild conditions within a short reaction time.

Trans-2-thien-α-oyl-3-[(un)substituted phenyl]-4-acetyl-5-methyl-2,3-dihydrofurans 3 were prepared in good yields with high stereoselectivity by the reaction of thien-α-oylmethyltriphenylarsonium bromide 1 with 3-[(un)substituted benzylidene]-2,4-pentadione 2 in benzene in the presence of potassium carbonate at 55 °C. The structure of compound 3 was confirmed by IR, MS, ¹H NMR, ¹H-¹H COSY, microanalysis and single crystal X-ray diffraction analysis. The possible reaction mechanism for the formation of products was also proposed.

Electrospray ionization mass spectrometry (ESI-MS) was utilized to perform monitoring of the intermediates in the reaction of 1,2,3-trisubstituted electron-deficient cyclopropane derivatives, cis-1-thien-2′-oyl-2-(p-subustituted phenyl-6,6-dimethyl)-5,7-dioxaspiro[2.5]-4,8-octadiones, with methanol. Key intermediates, either cationic or protonated forms of neutral species, were intercepted and characterized by ESI-MS and its tandem version (ESI-MS/MS). Therefore, the mechanism of the ring-opening process for electron-deficient cyclopropane derivatives was fully confirmed by the intermediates monitored.