An inexpensive fluorescent labeling protocol for bioactive natural products utilizing Cu(I)-catalyzed Huisgen reaction

Synthesis of new asymmetric xanthene dyes via catalyst-free SNAr with sulfur nucleophiles

“…S4 and S5 †). Thus, in keeping with previous reports, 30 the linker length is appropriate for click labeling with fluorescein 4a, but bulky halogen substituents appear to interfere.…”

“…Alkyne containing reactive dyes with a similar linker length have been obtained via O-alkylation. 30,31 Xanthene thioether dye azides (4a, 4b, 4d) were easily synthesized from 2a, 2b and 2d by conversion of the aliphatic alcohol into a leaving group, followed by substitution with azide in moderate yields (Scheme 2). Furthermore, a direct introduction of a Boc-protected amino function via the S-nucleophile S N Ar was performed.…”

The present and future synthetic strategies of structural modifications of sinomenine

“…Halogenation of 1 with N-halosuccinimide (NXS, X = Cl, Br or I) resulted in aryl halides 3a-c with moderate to high yields (55-85%, Scheme 1). 15,16 In the absence of the enone moiety, the iodination of C-ring non-functionalized derivatives also provided iodide 4 with a comparable yield (84%). 17 Halogenations using NXS also worked well in other substrates with 1,2-and 1,4-reduced enone of the C-ring.…”

Synthesis of N 11-anchoring biotinylated artemisinin derivatives and their preliminary biological assessment

“…Biotin-avidin system, which presents high stability and specificity, has often been used for the identification of target proteins of bioactive natural products and other small molecules [8,9]. Because of the biological importance of artemisinin and its derivatives [10,11], obtaining biotinylated artemisinin derivatives suitable for further biological study is of extreme importance [12,13]. Recently, Singh and coworkers reported a novel modification of artemisinin at the position of O-11 with various amines or hydrazines [14].…”