Tandem Denitrogenation Oxidative Coupling Reaction of Phenyl Vinyl Azides and Cyclic Ethers Under Metal‐Free Conditions

Abstract

An efficient synthesis of α‐oxoalkyl ketones is described. The current method is the coupling reaction of phenyl vinyl azides and cyclic ethers under metal‐free conditions. The reaction is conducted with KI as the additive and TBHP (70 % solution in water) as the oxidant at 60 °C for 12 h. A wide range of α‐oxyalkylated ketones with broad functionalities has been synthesized in moderate to good yields.

Visible-Light-Driven Denitrogenative C–C Bond Formation and Oxidative Difunctionalization of Vinyl Azides

“…55 After that, intermediate VI was formed via two possible pathways: one is the H abstraction (a) of iminyl radical, another undergoes the SET (b), then H + abstraction of intermediate V. Finally, the radical intermediate VI undergoes hydrolysis to convert the intermediate into the final product -oxyalkylketones (products 3 and 5). [56][57][58][59] In summary, we are motivated by an initial design concept of exploring the direct synthesis of -oxyalkyl ketone from vinyl azides by combining the power of C-H functionalization and visible-light photocatalysis. 60 We have established a straightforward, versatile protocol and operated under mild reaction conditions.…”

“…Finally, the radical intermediate VI undergoes hydrolysis to convert the intermediate into the final product α-oxyalkylketones (products 3 and 5 ). 56 57 58 59…”

Metal-free photoinduced denitrogenative alkylation of vinyl azides with alkyl radicals toward ketones

“…17 Besides the independent reactivities of an alkene and azide, the combination of the two groups results in some unique reactivities, and they can be used as nucleophiles, 18 electrophiles 19 and radical acceptors. 20 In particular, a vinyl azide captured by a carbon radical under visible light irradiation, followed by hydrolysis to yield ketones is an interesting and green alternative method compared to the classical methods for ketone synthesis. However, only limited examples have been documented so far.…”

Copper-Catalyzed Radical Relay 1,3-Carbocarbonylation across Two Distinct C═C Bonds

“…On the basis of the control experiments and the previous related reports, ,,− we tentatively propose a reaction mechanism in Figure . First, as a radical precursor, α-carbonyl alkyl bromide 1 undergoes SET under Cu I to produce an alkyl carbon radical intermediate I , , which simultaneously releases [Cu II ]-Br.…”

“…Next, the rapid denitrogenization after radical relay reaction between intermediate II with the CC bonds of vinyl azide 2 produces imine radical intermediate III , and the adduct ( 8a ) of the key intermediate with BHT is also detected by HRMS. Lastly, the protonation of III occurs to yield intermediate IV , which is converted into the final product 3 through rapid hydrolysis in the presence of H 2 O …”