Lewis‐Acid‐Mediated One‐Pot Tandem Reactions for Synthesis of Structurally Diverse Furo[3,2‐c]coumarins

Abstract

A concise, one-pot route for the synthesis of furo[3,2-c]coumarins under the catalysis of Zn(OTf) 2 is reported. Utilizing this synthetic strategy, libraries of furocoumarin analogues can be easily obtained by multicomponent tandem reactions with different nucleophile in the presence of 4-hydroxycoumarin and arylglyoxal monohydrate system, This transformation exhibited highly atom economical and good functional group compatibility.

Aryl glyoxal: a prime synthetic equivalent for multicomponent reactions in the designing of oxygen heterocycles

“…When the strategy was extended by involving aliphatic cyclic ketones, like cyclochexanone, to diversify the products, the use of Cu(OTf) 2 in the solvent dichloroethane (DCE) at 110 °C in a sealed vessel gave the best results, with a 76% yield (Scheme 62). 84 The proposed reaction design (Scheme 63) follows the pathway initially from the loss of a water molecule through the condensation reaction of 1 and 72 Next, a facile and one-pot novel methodology was described by Melekhina's group for the synthesis of furan-2(5H)-one derivative 10 with indole 9 as a structural fragment. The reaction was carried out in two steps, starting with the interaction of 4-methoxy aryl glyoxal 1, indole, and Meldrum's acid 8 in acetonitrile with triethylamine at reux, followed by a further acidic reux using acetic acid.…”

“…When the strategy was extended by involving aliphatic cyclic ketones, like cyclochexanone, to diversify the products, the use of Cu(OTf) 2 in the solvent dichloroethane (DCE) at 110 °C in a sealed vessel gave the best results, with a 76% yield (Scheme 62). 84 The proposed reaction design (Scheme 63) follows the pathway initially from the loss of a water molecule through the condensation reaction of 1 and 72 to give the intermediate ra , which reacts with the enol form of acetone in a Michael-type addition to produce the second intermediate rb . The electrophilicity of the condensed adduct ra is enhanced by the Zn(OTf) 2 .…”

Recent Advances on Sustainable Synthesis of Furocoumarins

“…In the year 2021, Chen and his associates described a concise one‐pot route for the synthesis of furocoumarin derivatives from the reaction of 4‐hydroxycoumarin, phenylglyoxal monohydrate and acetone in the presence of Zinc triflate ( Scheme 46). [85] According to the findings, arylglyoxals with electron‐neutral, electron‐rich substituents were successfully converted to the intended annulation products in good yields, whereas arylglyoxals with electron‐deficient substituents gave the corresponding product in a moderate yield. Notably, no product was formed when the strong electron‐withdrawing group such as the ‐NO 2 group was substituted on the phenyl ring.…”

Synthesis Of Dipyrrolobenzo[1,2‐a : 2′,1′‐c][1,4]diazepine Scaffold Via Three‐Component Reaction

“…The authors have cited additional references within the Supporting Information. [36][37][38][39][40][41]…”