Trisequential Photooxygenation Reaction: Application to the Synthesis of Carbasugars

Abstract

4,5-Dimethylenecyclohex-1-ene was subjected to a photooxygenation reaction to introduce oxygen functionalities. The endoperoxide obtained underwent an ene-reaction to form hydroperoxides with 1,3-diene structures. Further addition of singlet oxygen to the diene units resulted in the formation of tricyclic hydroperoxides having three oxygens in the molecule. Cleavage of the oxygen-oxygen bonds followed by epoxidation of the remaining C-C double bond and concomitant ring-opening reaction furnished the isomeric carbasugars.

Using Singlet Oxygen to Synthesize Natural Products and Drugs

“…159 From 2014, a report described the TPP-sensitized photooxidation of cyclohexa-1,3-diene 36 (Scheme 9). 160 The addition of 1 O 2 to 36 occurred in the expected [2 + 4] pathway, leading to endoperoxide 37, which was reduced and acetylated to afford diacetate 38, and two additional steps led to DL-tetrol 39. In a related report in 2014, 161 other carbasugars such as DL-pentaol 40 arise from endoperoxide 28 following a similar strategy.…”

Potassium Poly(Heptazine Imide): Transition Metal‐Free Solid‐State Triplet Sensitizer in Cascade Energy Transfer and [3+2]‐cycloadditions

“…The chemistry of O 2 .− and 1 O 2 could not be more different . O 2 .− participates in proton abstraction, disproportionation, or nucleophilic substitution reactions, while the most prominent reactions of 1 O 2 are Diels–Alder cycloaddition and formation of dioxetanes …”

“…[23] O 2 C À participates in proton abstraction, disproportionation, or nucleophilic substitution reactions, [24] while the most prominent reactions of 1 O 2 are Diels-Alder cycloaddition and formation of dioxetanes. [25][26][27] Numerous small organic compounds have been reported to sensitize 1 O 2 :I r(ppy) 3 , [28] Ru(bpy) 3 Cl 2 , [29] [Mes-Acr] + ClO 4 À , [23] riboflavin tetraacetate (RFT), [30] just to name af ew.E ase of separation, higher thermo-chemical stability, and possible application on large scale make solid-state sensitizers more attractive than homogeneous analogues. pconjugated triplet sensitizers have been atopic of research in past decades and have been quite successfully used in areas such as light energy conversion, LEDs fabrication, [31,32] photon upconversion, [33][34][35] cells imaging.…”

Kalium‐Polyheptazinimid: Ein übergangsmetallfreier Festkörper‐Triplett‐Sensibilisator in Kaskadenenergietransfer und [3+2]‐Cycloadditionen

“…[23] O 2 C À ist an Protonenabstraktion, Disproportionierung oder nukleophilen Substitutionsreaktionen beteiligt, [24] während die bekanntesten Reaktionen von 1 O 2 die Diels-Alder-Cycloaddition und die Bildung von Dioxetanen sind. [25][26][27] Es wurde berichtet, dass zahlreiche kleine organische Verbindungen 1 O 2 sensibilisieren:Ir(ppy) 3 , [28] Ru(bpy) 3 Cl 2 , [29] [Mes-Acr] + ClO 4 À , [23] Riboflavintetraacetat (RFT), [30] um nur einige zu nennen. Leichte Tr ennbarkeit, hçhere thermochemische Stabilitätu nd mçgliche Anwendung im großen Maßstab machen Festkçrpersensibilisatoren attraktiver als homogene Analoga.…”

“…Die Chemie von O 2 .− und 1 O 2 könnte unterschiedlicher nicht sein . O 2 .− ist an Protonenabstraktion, Disproportionierung oder nukleophilen Substitutionsreaktionen beteiligt, während die bekanntesten Reaktionen von 1 O 2 die Diels‐Alder‐Cycloaddition und die Bildung von Dioxetanen sind …”