Photoredox-catalyzed arylation of isonitriles by diaryliodonium salts towards benzamides

• Nadezhda M. Metalnikova,
• Nikita S. Antonkin,
• Tuan K. Nguyen,
• Natalia S. Soldatova,
• Alexander V. Nyuchev,
• Mikhail A. Kinzhalov and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2025, 21, 1480–1488, doi:10.3762/bjoc.21.110

• resulting aryl radical is subsequently captured by an isonitrile molecule, forming an imidoyl radical intermediate X1. The intermediate X1 facilitates the reduction of the Ru(III) species back to Ru(II) thereby completing the photoredox cycle, with the formation of the cationic intermediate X2. We propose

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

• -determining step. Based on these results, a detailed mechanism was proposed (Scheme 10) in which a copper-assisted homolysis of DCP generates a cumyloxyl radical A, which initiates the formation of an imidoyl radical B from the isocyanide. This radical then undergoes homolytic cleavage to yield an alkyl

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• '-azobis(isobutyronitrile) (AIBN). Then, E• adds to isocyanide 1 to form imidoyl radical 2, which abstracts hydrogen from E–H. The addition reaction proceeds by a radical chain mechanism, producing the 1,1-addition product 3 with regeneration of E•. In method 2, E• is generated by homolysis of a heteroatom

• •). The formed R’S• adds to isocyanide (RNC) to generate imidoyl radical intermediate 2 (E = R’S), which abstracts hydrogen from thiol to give the corresponding thioformimidate 3 (E = R’S) with regeneration of R’S•. Thus, the hydrothiolation of isocyanides with thiols proceeds by the radical chain

• can add to isocyanides to form the imidoyl radicals. In this reaction, telluro radicals (ArTe•) also forms in situ, but the relative reactivity of them toward isocyanides might be very low. In addition, dimerization of ArTe• to (ArTe)2 is very fast, and therefore, the ArTe-substituted imidoyl radical

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• and a PPh3–I radical III. The subsequent isocyanide 44 SOMOphilic insertion reaction led to the formation of an imidoyl radical B. This radical then underwent rapid addition onto the C–C double bond, resulting in the release of the desired phenanthridine products 45. Importantly, this process also

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

• Alessandra Del Tito,
• Havall Othman Abdulla,
• Davide Ravelli,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

• nucleofugal group X−, the intermediate R·, that is in turn trapped by 4.1 (path b). The resulting imidoyl radical 4.2· undergoes cyclization to 4.3· (path c) that is oxidized by PC·+, thus restoring the starting photocatalyst PC and forming the Wheland intermediate 4.3+ (path d). Deprotonation of 4.3+ (path e

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• eliminated the imine-H and formed the imidoyl radical, added to the phenyl ring. The homolytic aromatic substitution was terminated by H-atom abstraction by another t-BuO• radical. Among very few routes targeting the synthesis of 5,6-unsubstituted phenanthridines, the here presented radical-based pathway