Hypervalent iodine-catalyzed amide and alkene coupling enabled by lithium salt activation

• Akanksha Chhikara,
• Fan Wu,
• Navdeep Kaur,
• Prabagar Baskaran,
• Alex M. Nguyen,
• Zhichang Yin,
• Anthony H. Pham and
• Wei Li

Beilstein J. Org. Chem. 2024, 20, 1405–1411, doi:10.3762/bjoc.20.122

• tethered with a nucleophile to avoid the lack of regiochemical additions (Scheme 1a) [21][22][23][24][25][26][27][28]. Intermolecular hypervalent iodine-catalyzed olefin difunctionalizations have been realized for olefin dihalogenation, dioxygenation and diamination reactions, where often the same type of

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• cyclization affording the final product. Similarly, the dioxygenation of vinylarenes by diols was realized affording 1,4-dioxaheterocycles [112] (Scheme 21B). Triarylimidazoles have found similar applications as mediators for electrochemical oxidations [113] (Scheme 22). The reaction was suggested to proceed

• -coupling involving aldehyde C–H bond cleavage. DABCO-derived cationic catalysts in inactivated C–H bond cleavage for alkyl radical addition to electron-deficient alkenes under photoredox catalysis conditions. Electrochemical diamination and dioxygenation of vinylarenes catalyzed by triarylamines

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes

• Xiang Li,
• Pinhong Chen and
• Guosheng Liu

Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154

• ], aminofluorination [29], dioxygenation [30][31], and diamination [32][33] of alkenes could be achieved. Especially, when a nucleophile-tethered alkene is used, a cyclization product was obtained [34][35], although, stoichiometric amounts of hypervalent iodine(III) reagents were required. Due to the metal-like

• alkenes as well as some asymmetric reactions employing a chiral iodoarene. Review Dioxygenation of alkenes In 2009, Yan and co-workers reported an efficient catalytic method for the sulfonyloxylactonization of alkenoic acids (Scheme 2) [43], which employed catalytic amounts of hypervalent iodine(III

• rationalized by Woodward dioxolane intermediates (Scheme 3). Stereoselective dioxygenation using catalytic amounts of chiral hypervalent iodine reagents is a comparatively new area in hypervalent iodine chemistry. Fujita and co-workers described a stereoselective oxylactonization reaction in the presence of a

A survey of chiral hypervalent iodine reagents in asymmetric synthesis

• Soumen Ghosh,
• Suman Pradhan and
• Indranil Chatterjee

Beilstein J. Org. Chem. 2018, 14, 1244–1262, doi:10.3762/bjoc.14.107

• a new class of chiral hypervalent iodine reagents 49–52 to furnish 48 with moderate enantioselectivity (Scheme 10) [44][45][46][47]. Their constant efforts towards alkene dioxygenation helped them to discover new chiral hypervalent iodine reagents and also to reach up to 65% enantioselectivity using

Difunctionalization of alkenes with iodine and tert-butyl hydroperoxide (TBHP) at room temperature for the synthesis of 1-(tert-butylperoxy)-2-iodoethanes

• Hao Wang,
• Cui Chen,
• Weibing Liu and
• Zhibo Zhu

Beilstein J. Org. Chem. 2017, 13, 2023–2027, doi:10.3762/bjoc.13.200

• dioxygenation [10][11], dihydroxylation [10][12], bisperoxidation [13], oxyamidation [14], aminohydroxylation [15], oxyphosphorylation [16], deamination [17] and carbonylation–peroxidation [18]. Several very recent reports have pertained to metal-free catalysts for difunctionalization of alkenes such as UV

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• M−1s−1 [19]) trapping trans,cis peroxyl radicals before they underwent β-fragmentation (Scheme 5). In accordance with this free-radical mechanism, Schmidt and Alexanian more recently reported the aerobic dioxygenation of alkenyl N-aryl hydroxamic acids (Scheme 6) [21]. In this case dioxygenation

• selective oxidation of organic substrates. Radical addition of aldehydes and analogues to alkenes. NHPI/AIBN-promoted aerobic oxidation of 2,6-diisopropylnaphthalene. NHPI/AIBN-promoted aerobic oxidation of CHB. NMBHA/MeOAMVN promoted aerobic oxidation of PUFA. Alkene dioxygenation by means of N-aryl

Copper-catalyzed aerobic aliphatic C–H oxygenation with hydroperoxides

• Pei Chui Too,
• Ya Lin Tnay and
• Shunsuke Chiba

Beilstein J. Org. Chem. 2013, 9, 1217–1225, doi:10.3762/bjoc.9.138

• (for Table 3, entries 1 and 2) and fragmented ketones 7 (for Table 3, entries 1–4) were observed as minor products. Our next challenge was to develop direct aerobic dioxygenation of alkanes using the present radical strategy. The generation of C-radicals from alkanes at C–H bonds bearing relatively

• 3% yields, respectively, via the desired 1,4-dioxygenation, while benzophenone (7b) was also formed in 30% yield through fragmentation of the transient alkoxy radical (Scheme 4). Use of 40 mol % of NHPI slightly improved the yields of 1,4-dioxygenation products 2i and 3i (40% and 4% yields

• direct 1,4-dioxygenation of alkane 10 was demonstrated by using the present method. Further studies will be carried out to develop more robust and efficient catalytic aerobic radical transformations for polyol synthesis from rather simple alkanes. Aliphatic C–H oxidation with amidines and ketimines by

Study on the total synthesis of velbanamine: Chemoselective dioxygenation of alkenes with PIFA via a stop-and-flow strategy

• Huili Liu,
• Kuan Zheng,
• Xiang Lu,
• Xiaoxia Wang and
• Ran Hong

Beilstein J. Org. Chem. 2013, 9, 983–990, doi:10.3762/bjoc.9.113

• 321004, China 10.3762/bjoc.9.113 Abstract A “stop-and-flow” strategy was developed for the chemoselective dioxygenation of alkenes with a PIFA-initiated cyclization. This method is conceived for the desymmetrization of seco-diene, and a series of substituted 5-hydroxymethyl-γ-lactones were constructed

• after hydrolysis. This strategy also differentiates terminally substituted alkenes and constitutes a potentially novel synthetic approach for the efficient synthesis toward velbanamine. Keywords: alkene; desymmetrization; dioxygenation; lactone; PIFA; velbanamine; Introduction Stictosidine-derived

• ) [25]. The terminal alkene 6 can be disconnected to give amide 7, which may be derived from 2-bromotryptamine 9 and seco-diene 10. Clearly, the chemoselective dioxygenation of 10 is the main theme in our synthetic endeavor. From here, we expect that current synthetic methods may provide a general basis