Synthesis of furo[3,2-c]coumarins under microwave irradiation using nano-CoFe2O4@SiO2–PrNH2 as an efficient and magnetically reusable catalyst

CeO2/CuO@N‐GQDs@NH2 nanocomposite as a high‐performance catalyst for the synthesis of benzo[g]chromenes

“…The amino groups distributed on the surface of CeO 2 /CuO@N‐GQDs activated the C=O and C ≡ N groups through hydrogen bonding. [ 38–41 ] The activity of catalysts was influenced by the acid–base properties and many other factors such as surface area, geometric structure (particularly pore structure), the distribution of sites and the polarity of the surface sites. [ 38, 42 ] This mechanism is supported by the literature.…”

Recent Advances on Sustainable Synthesis of Furocoumarins

“…Again Ghomi and co‐workers reported the synthesis of furo[3,2‐ c ] coumarins by using 4‐hydroxycoumarin, aromatic aldehyde and 2,4’‐dibromoacetophenone in the presence of CoFe 2 O 4 @Si‐PrNH 2 as catalyst under microwave irradiation ( Scheme 9). [44] The catalyst was recovered using an external magnet, reused after washing with acetone and dried at room temperature. Again the role of cobalt ferrite nanocomposite, which serves as a magnetically recoverable catalyst is to provide better surface area for the substrates that can easily assist in the formation of active intermediate over the catalyst surface and hence can lead to desired product formation as discussed in Scheme 8.…”

Recent advances in the application of ylide-like species in [4 + 1]-annulation reactions: an updated review

“…Apart from quaternary ammonium ylides, pyridinium ylides react via [4 + 1]-annulation with 1,3-dicarbonylydene compounds, as demonstrated in a number of recent works (Scheme 42). 83–90 Pyridinium ylides 115 are often generated in situ from α-haloketones 61 and pyridine, while 1,3-dicarbonylydenes are formed by condensation of 1,3-dicarbonyl compounds 114 with aldehydes. The combination of these reactions in a one-pot process provides an expedient multi-component excess to annulated dihydrofurans 116 .…”