Zinc-catalyzed C–H alkenylation of quinoline N-oxides with ynones: a new strategy towards quinoline-enol scaffolds

Abstract

A zinc-catalyzed C-H alkenylation of quinoline N-oxides with ynones was developed to rapidly assemble a broad collection of valuable quinoline-enol organic architectures. Uncommonly, this novel reaction involve in C-H functionalization,...

Catalyst-free synthesis of quinoline-enols through coupling between heterocyclic N-oxides and CF3-ynones under mild conditions

“…According to these results and previous reports, 7,13,14 we proposed a plausible pathway for this process (Scheme 5). With the strong electrophilicity of CF 3 -ynone, the [3 + 2] annulations between quinoline N-oxide (1a) and CF 3 -ynone (2a) could proceed in the absence of a catalyst at room temperature, delivering the isoxazol intermediate I.…”

“…6 In 2021, Ma and Nan revealed a zinc-catalyzed C2 alkenylation of quinoline N -oxides with ynones to form quinoline-enols which could be further transformed into “BODIPY” analogues (Scheme 1(d)). 7 Alternatively, metal-free approaches were also investigated by several groups for the efficient C2-functionalization of N -oxides. In 2016 and 2017, the Wu group 8 and the Wang group 9 independently developed metal-free coupling between quinoline N -oxides and alkenes (Scheme 1(e)).…”

Recent advances in the synthesis of luminescent tetra-coordinated boron compounds

“…Quinazolinone based BF 2 compounds of the framework 165 with various substituents on the phenolate ring also showed the AIEE phenomenon. 168 Naphthyridine 140,164 and pyrimidine 158 based BF 2 compounds were synthesized and studied for their potential applications in biochemistry (166)(167)(168)(169). N,O-chelated naphthyridine based boron compounds 166 and 167 were studied as probes for the detection of phosphate ions.…”

“…The type of aryl group, spacers and mode of coordination had influence on the photophysical properties of the resultant products. 135–169 The Lu group 142,149 synthesized N,O-chelated BF 2 compounds 138–142 (Fig. 17).…”

Rhodium-Catalyzed C–H Annulation of Free Anilines with Vinylene Carbonate as a Bifunctional Synthon

“…Regarding this technique, one reagent is capable of concurrently performing two different types of reactivity to accomplish MCRs, which would minimize additional competing reactions via lessening the variety of reagents. Indeed, great efforts have been devoted and several difunctional reagents, for instance, aryl halides, alke­(y)­nes, (iso)­nitriles, carbonylating reagents, diazoes, and so forth, have been discovered to enable architecturally complex molecules efficiently. Meanwhile, synthetic chemists have started concentrating on merging MCRs with the remarkable and blooming C–H conversons, although the reported appropriate difunctional reagents are quite scarce, mainly focusing on the alkyne units.…”