One-Pot Domino Synthesis of Polyfunctionalized Benzophenones, Dihydroxanthones, andm-Terphenyls from 2-(Polyfluoroalkyl)chromones

Recent advances in the synthesis of cyclic compounds using α,α-dicyanoolefins as versatile vinylogous nucleophiles

This article provides a review of the applications of α,α-dicyanoolefins as versatile vinylogous nucleophiles in the synthesis of various cyclic compounds, covering the literature from the past 13 years.

Metal-free and solvent-free synthesis of m-terphenyls through tandem cyclocondensation of aryl methyl ketones with triethyl orthoformate

Reported here is a novel cyclocondensation of aryl methyl ketones and triethyl orthoformate for the simple synthesis of m-terphenyls. In the presence of a catalytic amount of TfOH, alkyl- and chloro-substituted acetophenones produced a series of terphenyls through a tandem reaction which merged six steps into a one-pot procedure. Moreover, the corresponding ester products were obtained when using other substituted acetophenones as the starting materials under the same reaction conditions.

A facile metal-free and solvent-free benzannulation was developed for the construction of m-terphenyl derivatives starting from aryl methyl ketones and triethyl orthoformate. This is a tandem reaction which merged six steps into one-pot procedure.

4-Trifluoromethyl-p-quinols as dielectrophiles: three-component, double nucleophilic addition/aromatization reactions

In recent years, numerous methods have emerged for the synthesis of trifluoromethylated arenes based on the late-stage introduction of a trifluoromethyl group onto an aryl ring. In sharp comparison, the synthesis of trifluoromethylated arenes based on the pre-introduction of a trifluoromethyl group onto an "aromatic to be" carbon has rarely been addressed. It has been found that 4-trifluoromethyl-p-quinol silyl ethers, the readily available and relatively stable compounds, can act as dielectrophiles to be applied to multi-component reactions for the synthesis of various trifluoromethylated arenes. Catalyzed by In(OTf)3, 4-trifluoromethyl-p-quinol silyl ethers react with C-, N-, and S-nucleophiles, respectively, in a regiospecific 1,2-addition manner to generate the corresponding highly reactive electrophilic intermediates. Further reaction of the in-situ generated electrophiles with a C-nucleophile followed by spontaneous aromatization enables the construction of functionalized trifluoromethyl arenes. This three-component, double nucleophilic addition/aromatization reaction based on the pre-introduction of a trifluoromethyl group onto an "aromatic to be" carbon provides a divergent strategy for the synthesis of trifluoromethylated arenes under mild reaction conditions in a single operation.

One-pot synthesis of functionalized benzo[c]coumarins and their precursors via the reaction of 2-(polyfluoroalkyl)chromones with 4-alkyl-3-cyanocoumarins

2-(Polyfluoroalkyl)chromones react with 4-alkyl-3-cyanocoumarins in dichloromethane in the presence of triethylamine to give a wide variety of functionalized benzo[c]coumarin derivatives in good yields.