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

• , People’s Republic of China Zhejiang Lvgu Biopharmaceutical Co., Ltd., No.16 Bailian Road, Nanmingshan Street, Lishui City 323000, Zhejiang Province, China 10.3762/bjoc.21.98 Abstract The field of radical-mediated functionalization of N-arylacrylamides has experienced considerable advancements in recent

• years, particularly in the domain of oxidative radical difunctionalization reactions employing carbon radical reagents. This approach provides a powerful and versatile strategy for the concurrent introduction of two distinct functional groups across the double bond of N-arylacrylamides, facilitating the

• rapid construction of complex molecular architectures. This review aims to summarize the diverse strategies for inducing intramolecular transformations of N-arylacrylamides using various carbon radical reagents, including methods initiated by photonic, thermal, or electrochemical processes, which have

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

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

• -heterocycles. Recently, independent research groups led by Li, Yang, and Patureau separately disclosed a novel approach to 3,3-disubstituted oxindoles 43 through an iodide/phosphine-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides 42 (Scheme 18) [35][36

• and γ,σ-unsaturated N-(acyloxy)phthalimides. Proposed mechanism for the decarboxylative [3 + 2]/[4 + 2] annulation. Decarboxylative cascade annulation of alkenes/1,6-enynes with N-hydroxyphthalimide esters. Decarboxylative radical cascade cyclization of N-arylacrylamides. NaI/PPh3-driven

NaI/PPh₃-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles

• Dan Liu,
• Yue Zhao and
• Frederic W. Patureau

Beilstein J. Org. Chem. 2023, 19, 57–65, doi:10.3762/bjoc.19.5

• Dan Liu Yue Zhao Frederic W. Patureau Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany 10.3762/bjoc.19.5 Abstract A practical NaI/PPh3-catalyzed decarboxylative radical cascade cyclization of N-arylacrylamides with redox-active esters is described, which

• disclosed a visible light-mediated radical tandem cyclization of N-arylacrylamides with N-(acyloxy)phthalimides to access 3,3-dialkylated oxindoles in the presence of [Ru(bpy)3Cl2]·6H2O [46]. However, these seminal methods remain limited by the need of noble-metal-based photocatalysts, excess additives and

• by these advances, we developed here a visible light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides under NaI/PPh3 catalysis, for the most efficient and practical synthesis of quaternary oxindoles (Scheme 1b and 1c). It should be noted that during the finalization of this

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• aliphatic nitriles explored, the reaction further demonstrated the synthetic potential of C(sp3)–H species within CDC methodology. In 2013, the Li group established a carbonyl-arylation of N-arylacrylamides 60 with alkyl and aryl aldehydes 65 (Scheme 11) [83]. Like Li’s report in 2013 (Scheme 10) [80], the

• -disubstituted counterparts, perhaps due to the generation of the more stable 3° radical intermediate. In the following year, Song and Li reported a reaction shortcut for the carbonyl-arylation of N-arylacrylamides 60 through the in-situ oxidation of alcohols 67 (Scheme 11) [84]. Under the optimized reaction

• formal elimination of H2. This section is categorized by the initiating step and the types of bonds being formed. Denitrogenative C–C/C–C coupling In 2014, Yu’s and Du’s groups independently described the arylcarbonylation of alkenes for the synthesis of oxindoles 118 from N-alkyl,N-arylacrylamides 60

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• tandem trifluoromethylation/cyclisation processes. Dolbier and co-workers first proposed the use of N-arylacrylamides 3 to access trifluoromethylated 3,3-disubstituted 2-oxindoles 4 under photocatalytic conditions (Scheme 4) [11]. In the presence of Ru(phen)3Cl2 (phen = phenanthroline), a variety of N

• reduction potential of Cu(dap)2Cl in the excited state, and its important ability to mediate the transfer of the Cl atom. Consequently, a variety of electron-deficient alkenes, such as N-arylacrylamides, acrylonitrile, acrylate and enone derivatives furnished their chlorotrifluoromethylated analogues in

• silyl enol ethers. Continuous flow trifluoromethylation of ketones under photoredox catalysis. Trifluoromethylation of enol acetates. Photoredox-catalysed tandem trifluoromethylation/cyclisation of N-arylacrylamides: a route to trifluoromethylated oxindole derivatives. Tandem trifluoromethylation

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• carbotrifluoromethylation of N-arylacrylamides 46 with CF3SO2Na to produce oxindoles 47 [45]. Addition of the CF3 radical to such an electron-deficient alkene should be unfavourable. However, the subsequent annulation step drove the cascade process toward oxindole synthesis. The reaction utilised Langlois’ conditions with

• -substituted phenyl rings produced mixtures of regioisomers. Under these metal-free conditions, it was proposed that the CF3 radical was formed uniquely by reaction of CF3SO2Na with K2S2O8. N-Arylacrylamides could also react with CF3SO2Na under metal-free conditions by replacing tert-butyl hydroperoxide or the

• with PhI•OAc. Addition of the CF3 radical to the alkene followed by intramolecular cyclisation mediated by PhI•OAc gave the desired oxindole with release of PhI and AcOH (Scheme 28) [49]. For another metal-free trifluoromethylation/cyclisation of N-arylacrylamides by means of a different oxidant, Liu