A concise and direct synthetic strategy for the construction of 2-aryliminochromene skeleton by cascade three-component coupling reaction of arynes, N,S-keteneacetals, and DMF in good yields has been disclosed. The process demonstrates the first example of aryne chemistry combined with N,S-keteneacetals. Using this strategy, an expeditious synthesis of biologically important arylimino-2H-chromene-3- carboxamides was achieved.
Full experiments and characterization data including 1 H and 13 C NMR spectra and HPLC for the synthesized products ((S)-3a−3aj and (S)-4−7) (PDF)Accession Codes CCDC 1963357 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk
An efficient and straightforward N-ethyldiisopropylamine (DIPEA)-catalyzed multicomponent bicyclization reaction was developed to synthesize furo[2,3-b]pyrrole derivatives from β-ketothioamides, glyoxals, and ethyl cyanacetate in EtOH at rt for 1.5 h. This was achieved via a sequential Knoevenagel condensation, Michael addition, and double cyclization, resulting in continuous formation of four chemical bonds (two C-C, two C-O, and one C-N bonds), two five-membered cycles, and three stereogenic centers in a one-pot operation.
Chiral phosphoric acid-catalyzed couplings of Calkynyl N, N'-di-(tert-butoxycarbonyl)-aminals with β-naphthols led to chiral propargylamines in moderate to high yields with high to excellent enantioselectivity, in which the reactions underwent sequential chiral phosphoric acid-catalyzed in situ formation of N-(tert-butoxycarbonyl)-imines (N-Boc-imines) from the aminals, and 1,2-addition of β-naphthols to the N-Boc-imines. Chiral 1,2-dihydronaphtho[2,1-b]furans and naphtho[2,1-b]furans were prepared with satisfactory results when 10 mol% AgOAc and 20 mol% 2,6-lutidine or 1.2 equiv. of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were added to the resulting chiral propargylamines solution, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.