Tandem Michael Addition–Cyclization of Nitroalkenes with 1,3-Dicarbonyl Compounds Accompanied by Removal of Nitro Group

Abstract

A tandem Michael addition–cyclization of nitroalkenes with 1,3-dicarbonyl compounds was developed using phase transfer catalyst (PTC), allowing for the synthesis of polysubstituted-[4,5]-dihydrofuran in high yields. A wide range of substrates were demonstrated by this one-step process. Meanwhile, nitro group was substituted to form corresponding nitrite ion detected in the aqueous phase providing a reasonable pathway for denitrating poisonous and explosive nitro-containing compounds. The proposed mechanism was also supported by our DFT calculations.

The Chameleonic Nature of the Nitro Group Applied to a Base-Promoted Cascade Reaction To Afford Indane-Fused Dihydrofurans

“…Also, the reaction with an in situ generated nitrodienes gives dihydrofurans . Furthermore, the nitro group can act as a leaving group, so the nucleophilic attack of an oxygen atom from the enol generates the dihydrofuran . It is of particular interest the work by Yue and co-workers, who reported a tandem Michael cyclization between 1,3-dicarbonyl compounds and nitroalkenes using a phase-transfer catalyst and potassium carbonate in DMF at 78 °C under a nitrogen atmosphere (Scheme c).…”

Basicity‐Controlled [3+2] Cyclization of 3‐Hydroxyquinolin‐ones and β‐Chlorinated Nitrostyrenes

“…[19][20][21][22][23][24][25] Inspired by this concept and our ongoing interest in the chemistry of β-chlorinated nitrostyrenes, [26][27][28][29][30][31] the recombination of quinolin-2-one and (dihydro)furan rings [32][33][34][35] from natural products afforded the (dihydro)furo[2,3-c]quinolin-4(5H)-one skeleton, which is not covered by nature (Scheme 1b). In detail, we hypothesized that the 3-hydroxyquinolin-2-one derivatives 1 could undergo Michael addition/cyclization process [36][37][38] through intermediates 5 and 6 to give dihydrofuro[2,3-c]quinolin-4(5H)-one derivatives 3 in the presence of simple base or chiral catalyst (Scheme 1b). Moreover, the further elimination of HNO 2 with suitable base could furnish the aromatized furo[2,3-c]quinolin-4(5H)-one derivatives 4.…”

A novel synthesis of dihydrofuranyl alcohols through cascade reactions of 1,3-diketones with α,β-unsaturated epoxides

“…24,25 Another synthetic application of 1,3-dicarbonyl compounds was in the preparation of polysubstituted dihydrofuran derivatives. [26][27][28][29][30][31][32] For example, a tandem reaction of α-haloalkynes with β-ketoacids could generate polysubstituted dihydrofuran carboxylates (Scheme 1b), but such transformation requires the use of complex organic ligands or heavy metal salts as catalysts, which would undoubtedly lead to a negative impact on the environment. In this work, we present an effective method for the construction of a highly substituted dihydrofuran skeleton through tandem reactions of 1,3-diketones with α, β-unsaturated epoxy compounds (Scheme 1c).…”