Photocatalytic Modular Cyanoalkylamination of Alkenes Involving Two Different Iminyl Radicals

Abstract

The modular cyanoalkylamination of alkenes using bench-stable and easy-to-handle α-imino-oxy acid oxime esters as difunctional reagents creates new synthetic avenues. A metal-free photosensitization protocol for the installation of both amino and cyanoalkyl functionalities onto alkene feedstocks in a single step via two differently reactive nitrogen-centered radicals was developed via energy-transfer catalysis. Excellent functional group tolerance and mild reaction conditions also render this protocol suitable for the cyanoalkylamination of pharmaceutically relevant molecule-derived alkenes.

Photocatalytic Regio‐ and Site‐Selective Alkylamination of Coumarins: Access to 3‐Amino‐ and 4‐Amino Dihydrocoumarins

“…Pioneering studies of Glorius, [11] Cho, [12] Huo, [13] Han, [14] Wu, [15] Yang, [16] Molander, [17] and our group [18] have developed a range of applications based on different radical bifunctionalized reagents. However, bifunctionalized modifications of the coumarin backbone to obtain functionalized dihydrocoumarins have been ignored, except for our example of poor regioselectivity (dr=2:1) [18b] …”

Photosensitized Vicinal Sulfonylamination of Alkenes with Oxime Ester and DABCO·(SO2)2

“…Considering the weak stability of the alkyl carbonyloxyl radical, CO 2 release or subsequent extrusion of another small molecule could be expected . Very recently, Glorius, Molander, Xia, and our group independently employed this strategy to accomplish a variety of difunctionalizations of alkenes by the rational design of bifunctional reagents. Despite these encouraging advances, modulating the reaction pathway by inserting another linker moiety after CO 2 extrusion in the process has been rarely explored.…”

Photoinduced Remote C(sp3)–H Imination Enabled by Vinyl Radical-Mediated 1,5-Hydrogen Atom Transfer

“…Benzophenone oxime esters are emerging as a promising class of bifunctionalized reagents because of their unique reactivity and ability to release persistent imine radicals and another class of radical species via energy transfer catalysis . Various olefin bifunctionalization reactions, including alkylamination, oxyimination, alkoxycabonylimidation, and diamination, using these types of biradical reagents have been reported (Figure ). Although these reagents have been widely utilized in olefin bifunctionalization reactions, their application in the functionalization of alkynes remains a research desert likely as a result of the poor stability of vinyl radical intermediates and the difficulty in capturing imine radicals without the help of additional metal catalysts …”