Synthesis of Benzo[b]phenanthridines and Related Naturally Occurring 2-Aryl-1,4-naphthoquinones by Palladium- and Copper-Catalyzed Coupling of Organostannanes with Bromoquinones

Abstract

Syntheses of phenanthroviridone, gilvocarcin BE‐12406X2, antibiotic WS 5995B, and a key intermediate for the synthesis of jadomycin are described, based on palladium‐ and copper‐catalyzed coupling reactions of sterically hindered arylstannanes with 2‐bromonaphthoquinones.

Synthesis and biological evaluation of new pyrazol-4-ylpyrimidine derivatives as potential ROS1 kinase inhibitors

“…But the comparable activity of compound 17 (fulfilling all features) and compounds 28 and 29 (missing polar side chain) makes the role of polar side chain in the potency somewhat unclear. It is also worthy to mention that the four active compounds in this second set (16,17,28, and 29) are far less active than most active compounds in the first set of compounds (6c, 6e, and 7c). It is also worth mentioning that comparing the IC 50 s of compounds KIST301072, 7c and 17 shows the importance of the phenolic group together with the 4-hydroxyl butyl amino side chain.…”

New Phenylaminopyrimidine (PAP) Anticancer Lead Compound with High Efficacy: Design, Synthesis, and in vitro Screening

“…12 The resulted Claisen compound underwent rearrangement and aromatization into 3-hydroxy-5-methylbenzoic acid (3) within less than one hour by heating with magnesium oxide in boiling water, followed by acidification with hy-drochloric acid to precipitate the product. 12 Methyl esterification and O-methylation of the resulted phenolic acid 3 were achieved in a single step and in a high yield (94%) to give compound 4 through a little modification of the reported literature procedure, 13 where the acid 3 was refluxed with excess potassium carbonate and iodomethane in acetone, and in the presence of a catalytic amount of dimethylaminopyridine.…”

“…Material. 1 H-NMR (300 MHz) and 13 C-NMR (75 MHz) were recorded on a Bruker Avance 300 spectrometer with TMS as an internal standard. The IR spectra were recorded on Perkin Elmer Spectrum GX spectrometer.…”

Organotin Reagents in Cross‐Coupling Reactions

“…An aryl transfer has also been used in the synthesis of 5,8-disubstituted α-tetralones [16], bis-C-glycosylated diphenylmethanes [161], Cglycosylated biphenyls [162], and 8-substituted tetracycline derivatives [163] (in this context, alkynyl transfer was also reported). Reactions between sterically encumbered aryl stannanes and 2-bromonaphthoquinones were reported by Echavarren et al [164], while Albrecht and Williams [165] assembled the biaryl moiety of the TMC-95 natural products by a Stille coupling, and Gundersen et al [166] prepared a series of 6-arylpurines to study their antibacterial activity. Okujima et al [167] prepared 6-tributylstannylazulene (the first organotin with an azulene moiety) from 6-bromoazulene and hexabutylditin; coupling with aryl and azulenyl halides was successful.…”