Palladium‐Catalyzed Dearomative syn‐1,4‐Oxyamination

Abstract

Ap alladium-catalyzed dearomative syn-1,4-oxyamination protocol using non-activated arenes has been developed. This one-pot procedure utilizes arenophile chemistry,a nd the corresponding para-cycloadducts are treated with oxygen nucleophiles via formal allylic substitution, providing direct access to syn-1,4-oxyaminated products.T he reaction conditions permit ar ange of arenes,a sw ell as different Onucleophiles,s uch as oximesa nd benzyl alcohols.M oreover, this process was established in an asymmetric fashion, delivering products with high enantioselectivity.T he dearomatized products are amenable to amultitude of further derivatizations ranging from olefin chemistry to CÀHactivation, giving rise to ad iverse set of new functionalities.O verall, this dearomative functionalization offers rapid and controlled formation of molecular complexity,e nabling straightforwarda ccess to functionalizeds mall molecules from simple and readily available arenes.

Selective skeletal editing of polycyclic arenes using organophotoredox dearomative functionalization

“…To our knowledge, only one example has been described in a recent report by Brown, Houk and Glorius involving a photochemical [4+2] cycloaddition between quinolines and alkenes (Figure 1b) 26 enabled by energy transfer and Lewis acid activation. A similar [4+2] cycloaddition strategy initiated by energy transfer was also employed in the dearomatization of naphthalene by Sarlah et al (Figure 1c) [27][28][29][30][31][32] .…”

Uncanonical Semireduction of Quinolines and Isoquinolines via Regioselective HAT-Promoted Hydrosilylation

“…Our dearomatization exploration commenced with the hypothesis that the photoexcited quinolinium intermediate might be reduced by a hydride reductant, − such as silane reagents, − to enable direct addition and reduction of the heteroarenes. During the solvent investigation, formation of an intriguing hydrosilylated product 11 was observed and subsequently optimized (Table , entry 1) .…”

“…Developing mild alternative strategies capable of breaking the strong aromaticity in Lewis basic heteroaryls and with regioselective control remains an outstanding challenge. Inspired by the elegant reports of photoinduced [4+2] cycloaddition between heterocycles and olefins − or triazolinediones, − we envisaged that photo-excited-state intermediates such as 7 might be leveraged to provide regioselective hydrosilylated products 8 and reduced products 9 from abundant feedstocks in a controlled manner (Figure C). The dearomative hydrosilylation of heterocycles, in particular, might provide unique opportunities to access novel medicinally relevant scaffolds in medicinal chemistry settings.…”