Additive‐Free Visible‐Light‐Initiated Three‐Component Cyanation and Azidation

Abstract

A simple and green visible-light-initiated strategy for the installation of cyano and azido groups has been established through multi-component reaction of α-diazoesters, cyclic ethers and TMSCN/TMSN 3 . A number of structurally diverse organic nitriles and azides could be efficiently obtained at room temperature without adding any external metal reagent, strong oxidant, base and photocatalyst. The synthetic transformations of the reaction products to some functionalized molecules were carried out to highlight the potential utility of this method.

Visible Light-Induced Reactions of Diazo Compounds and Their Precursors

“…103 Moreover, the same group demonstrated the utilization of TMSN 3 , TMSCN, pyrazolones, and dicarbonyl compounds as nucleophiles in three-component cascade reactions involving diazo compounds and cyclic ethers (Scheme 37i,j). 104,105 More recently, An and Wang's groups employed the in situ formed Osubstituted hydroxamic acids 37.38 toward various N-alkylated acrylamides 37.39 (Scheme 37k). 106 The photochemical cascade ring-opening reaction of oxonium ylides can be synergistically combined with NHC catalysis, thus further expanding the range of suitable substrates for this transformation.…”

“…Later, Wei’s group reported an analogous approach employing O 2 from the air for the synthesis of various phosphonates 37.32 and phosphinates (Scheme h) . Moreover, the same group demonstrated the utilization of TMSN 3 , TMSCN, pyrazolones, and dicarbonyl compounds as nucleophiles in three-component cascade reactions involving diazo compounds and cyclic ethers (Scheme i,j). , More recently, An and Wang’s groups employed the in situ formed O -substituted hydroxamic acids 37.38 toward various N -alkylated acrylamides 37.39 (Scheme k) …”

Visible light-mediated photolysis of organic molecules: the case study of diazo compounds

“…74 Several multicomponent reactions involving the use of cyclic ethers as solvent and a variety of nucleophiles have been reported to afford the corresponding more complex formal O-H insertion products, which are also presumably derived from the involvement of a key oxygen ylide intermediate. 61,62,64,[75][76][77][78][79][80][81][82][83][84] C-C insertion reactions could be achieved with 1,3-diketones 85,86 (with a rare successful example of enantioselective catalysis being demonstrated by Hui and co-authors employing a chiral phosphoric acid catalyst 86 ), and enaminones. 87 Condensation-type products have been also obtained starting from azides to afford imines, 34 and starting from isonitriles to afford ketenimine derivatives.…”

Light‐Induced Domino and Multicomponent Reactions: How to Reach Molecular Complexity without a Catalyst

“…When THF or cyclic ethers 128 were employed as the solvent, the latter actively participated in the reaction becoming one of the coupling partners. In this context, the groups of Jiang, Qi, Wei, Yue, Zhong, He and Xu extensively worked in this field, managing to develop different catalystand additive-free methodologies for the synthesis of carbamates 129, [98] phosphorothiates 131, [99] thiocyanates 133, [100] nitriles 138 and azides 139 [101] under blue light irradiation. Adjusting the reaction conditions according to the coupling partners, the α-aryldiazoesters 127 and THF were reacted with carbon dioxide and an amine 88, [98] elemental sulfur and Hphosphonates 120, [99] and TMSCN 137/TMSN 3 136, [101] respectively.…”

“…In this context, the groups of Jiang, Qi, Wei, Yue, Zhong, He and Xu extensively worked in this field, managing to develop different catalystand additive-free methodologies for the synthesis of carbamates 129, [98] phosphorothiates 131, [99] thiocyanates 133, [100] nitriles 138 and azides 139 [101] under blue light irradiation. Adjusting the reaction conditions according to the coupling partners, the α-aryldiazoesters 127 and THF were reacted with carbon dioxide and an amine 88, [98] elemental sulfur and Hphosphonates 120, [99] and TMSCN 137/TMSN 3 136, [101] respectively. Only in 2023, the reaction was extended to NaSCN 132 [100] and to organic phosphinic acids 134, the latter methodology was employed to produce phosphoric esters 135.…”