Convenient synthesis of indeno[1,2-c]isoquinolines as constrained forms of 3-arylisoquinolines and docking study of a topoisomerase I inhibitor into DNA–topoisomerase I complex

Antiviral Activity of Isoquinolone Derivatives against Influenza Viruses and Their Cytotoxicity

“…Among 23 isoquinolone compounds, 1 and 17–19 have been synthesized according to our established protocol ( Supplementary Scheme S1 ) [ 11 , 12 ]. Compounds 2 , 3 , 13–15 and 22 without the methylenedioxy group at R 2 were separately synthesized ( Supplementary Scheme S2 ) [ 13 , 14 , 15 , 16 ]. A newly designed synthetic method was used for phensylisoquinolone derivatives 7–10 and 21 , and these compounds were prepared in a one-step cyclization reaction using n-BuLi to link the N,N-diethyl-2-methylbenzamide and benzonitrile moieties ( Scheme 1 ).…”

“…Isoquinolone derivatives were synthesized as described previously [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. The structure of newly synthesized compounds 7– 10 and 21 was confirmed by 300 MHz (Varian Unity Plus 300 MHz; Varian Inc., Palo Alto, CA, USA) and 400 MHz (Bruker Ascend 400 MHz; Bruker Daltonik, Bremen, Germany) nuclear magnetic resonance (NMR) spectrometry.…”

Design and Synthesis of Indenoisoquinolines Targeting Topoisomerase I and Other Biological Macromolecules for Cancer Chemotherapy

“…Intramolecular nucleophilic attack of the enamide 107 on the protonated aldehyde then produced the cyclized secondary alcohol 108 , which was oxidized to the final product 38 with pyridinium dichromate. The cyclization of 107 to 108 under acidic conditions, as well as the oxidation of 108 to 38 , had previously been demonstrated by Cho et al during a synthesis in which 107 was set up by reaction of the lithium anion derived from N -methyl- o -methylbenzamide ( 140 ) with PMB-protected o -(hydroxymethyl)­benzonitrile ( 141 ) followed by N -methylation, deprotection of the alcohol, and oxidation to the aldehyde 107 (see Scheme below) . The scope of the pathway shown in Scheme was expanded to include products bearing methoxyl groups on the two aromatic rings …”

“…The synthesis outlined in Scheme involves the reaction of the anion derived from deprotonation of the starting material 140 followed by its reaction with the nitrile 141 to yield the intermediate 142 . Alkylation of the anion derived from deprotonation of the amide 142 with methyl iodide afforded the N -methyl derivative 143 , and the protecting group was then removed through oxidation with DDQ and hydrolysis.…”

Experimental and computational study of BF3-catalyzed transformations of ortho-(pivaloylaminomethyl)benzaldehydes: an unexpected difference from TFA catalysis

“…treatment of enamide-carbaldehyde 21 with HCl in acetone resulted in the formation of the five-membered C ring of tetracyclic derivatives 22 (Scheme 7). [19][20][21] The transient presence of "TFA dimer" 6a in the course of the BF 3 •H 2 O-catalyzed transformation of 5 was mentioned above, indicating that the primarily formed 6a might be transformed into products 14 and 15. Indeed, treatment of compound 6a with BF 3 •OEt 2 (0.19 eq.)…”