Correction: Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

• Ilya A. P. Jourjine,
• Lukas Zeisel,
• Jürgen Krauß and
• Franz Bracher

Beilstein J. Org. Chem. 2024, 20, 170–172, doi:10.3762/bjoc.20.16

• Ilya A. P. Jourjine Lukas Zeisel Jurgen Krauss Franz Bracher Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians University of Munich, Butenandtstraße 5–13, 81377 Munich, Germany 10.3762/bjoc.20.16 Keywords: cross-dehydrogenative coupling; cyclization; fluorenones; nobilone

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• are widespread as essential building blocks in various drugs, natural products, agrochemicals, and materials. Modern economy requires developing green strategies with improved efficiency and reduction of waste. Due to its atom and step-economy, the cross-dehydrogenative coupling (CDC) reaction has

• further development. To avoid the prefunctionalization of substrates, Li et al. first pioneered the concept of direct cross-dehydrogenative coupling (CDC) through continuous exploration and discovery [7][13][14][15]. The CDC reaction has flourished due to its versatility and has become an important

• of the radical initiator to the ether to obtain the corresponding ether radical species. The coupling product is accessed through a single electron transfer (SET) and other transformations. In 2019, Tu et al. established a highly efficient Cu-catalyzed cross-dehydrogenative coupling to access a

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

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• ). In 2015, a palladium-catalyzed cross dehydrogenative coupling of pyridine N-oxides with toluene for the regioselective arylation and benzylation of pyridine N-oxide was reported by Khan and co-workers [92] (Scheme 23). The authors have shown toluene 117 when used as benzyl and aryl source remained

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

• oxidative coupling processes (also known as cross-dehydrogenative coupling), as well as late-stage CH-functionalization. Oxidation processes are recognized as a challenge in fine organic synthesis technology [10][11] due to selectivity problems and frequent need for toxic transition metal salts and

• (hydroxylation, hydroperoxidation, halogenation, etc.), cross-dehydrogenative coupling and oxidative cyclization, alcohol oxidation, and the oxidation of other functional groups. Compared to other types of organocatalysis (type I and type II in Scheme 1) reversible bonding and non-covalent interactions of redox

Cyclometalated iridium complexes-catalyzed acceptorless dehydrogenative coupling reaction: construction of quinoline derivatives and evaluation of their antimicrobial activities

• Hongling Shui,
• Yuhong Zhong,
• Renshi Luo,
• Zhanyi Zhang,
• Jiuzhong Huang,
• Ping Yang and
• Nianhua Luo

Beilstein J. Org. Chem. 2022, 18, 1507–1517, doi:10.3762/bjoc.18.159

• Abstract The acceptorless dehydrogenative coupling (ADC) reaction is an efficient method for synthesizing quinoline and its derivatives. In this paper, various substituted quinolines were synthesized from 2-aminobenzyl alcohols and aryl/heteroaryl/alkyl secondary alcohols in one pot via a cyclometalated

• against Gram-positive bacteria and compound 3ck against C. albicans were better than the reference drug norfloxacin. Keywords: acceptorless dehydrogenative coupling reaction; antibacterial; cyclometalated iridium complexes; quinolines; Introduction As an important class of heterocyclic compounds

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

• significant development over the past 10 years. First achieved by Li and co-workers in 2007 [44], cross-dehydrogenative-coupling (CDC) reactions offer a highly atom economic approach to carbon–carbon (C–C) and carbon–heteroatom (C–X) bond formation via C–H activation [45][46]. Generally speaking, C–C bond

• . Iron-catalyzed cross dehydrogenative coupling Transition-metal-catalyzed carbon–carbon (C–C) or carbon–heteroatom (C–X) bond formation involving two different C–H bonds or one C–H and one X–H bond is formally known as cross dehydrogenative coupling (CDC) and is quite attractive to synthetic organic

• sections: strictly carbon CDC reactions and heteroatomic CDC reactions. Iron-catalyzed carbon–carbon cross dehydrogenative coupling In 2013, Li and co-workers reported the FeCl3-catalyzed arylalkylation of activated alkenes 60 for the synthesis of oxindoles 62 (Scheme 10) [80]. Mechanistic studies

Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

• Ilya A. P. Jourjine,
• Lukas Zeisel,
• Jürgen Krauß and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2668–2679, doi:10.3762/bjoc.17.181

• good yields via metal- and additive-free TBHP-promoted cross-dehydrogenative coupling (CDC) of readily accessible N-methyl-2-(aminomethyl)biphenyls and 2-(aminomethyl)biphenyls. This methodology is compatible with numerous functional groups (methoxy, cyano, nitro, chloro, and SEM and TBS-protective

• groups for phenols) and was further utilized in the first total synthesis of the natural product nobilone. Keywords: cross-dehydrogenative coupling; cyclization; fluorenones; nobilone; total synthesis; Introduction Fluorenones are an important class of aromatic natural products, and since the

• adverse effect on the yield of fluorenone (3). Addition of TBAI (Table 2, entry 10) in particular looked promising, as TBAI/TBHP-mediated radical cyclizations and cross-dehydrogenative coupling (CDC) reactions are not only well established [57], but addition of TBAI has been shown to increase the yield of

Photoredox catalysis in nickel-catalyzed C–H functionalization

• Lusina Mantry,
• Rajaram Maayuri,
• Vikash Kumar and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143

• bonds of N-arylamines. Proposed mechanism for the photocatalytic α‑acylation of ethers with acid chlorides. Proposed reaction pathway for the photoredox nickel-catalyzed dehydrogenative coupling of benzylic and aldehydic C–H bonds. Proposed mechanism for the nickel-catalyzed C(sp3)–H acylation with N

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

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

• , including oximes, was demonstrated [44]. In contrast to the cross-dehydrogenative coupling of oximes with 1,3-dicarbonyl compounds, both one-electron oxidants (Fe(ClO4)3, (NH4)2Ce(NO3)6) and two-electron oxidants (PhI(OAc)2, Pb(OAc)4), that vary greatly in properties, are applicable for this process. After

• optimization of the reaction conditions Fe(ClO4)3 was chosen as the optimal oxidant for the synthesis of C–O cross-dehydrogenative coupling products 51 (Scheme 19). The extremely persistent diacetyliminoxyl radical (20) [44] was directly introduced into the reaction with pyrazolones 50 with the formation of

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• supported the energy transfer pathway. Thus, the proposed triplet sensitization mechanism of the photocatalytic ATRA reaction is depicted in Scheme 25. In 2016, Ji and co-workers developed a new photoredox cross-dehydrogenative coupling (CDC) method for the α-heteroarylation of amides (α to nitrogen, e.g

• (52). Proposed triplet sensitization mechanism of the ATRA reaction in the presence of 4-anisaldehyde (52). Benzaldehyde-mediated photoredox CDC reaction: compatible amides and ethers. Photoredox cross-dehydrogenative coupling (CDC) conditions and proposed reaction mechanism. Optimized conditions for

Photocatalytic deaminative benzylation and alkylation of tetrahydroisoquinolines with N-alkylpyrydinium salts

• David Schönbauer,
• Carlo Sambiagio,
• Timothy Noël and
• Michael Schnürch

Beilstein J. Org. Chem. 2020, 16, 809–817, doi:10.3762/bjoc.16.74

• ] and pharmaceuticals [10][11]. Consequently, the direct functionalization of this scaffold has attracted significant interest in recent years. Even though many transformations have been realized via a cross-dehydrogenative coupling approach [12][13] (e.g., arylations [14][15], cyanomethylation [16

Synthesis and circularly polarized luminescence properties of BINOL-derived bisbenzofuro[2,3-b:3’,2’-e]pyridines (BBZFPys)

• Ryo Takishima,
• Yuji Nishii,
• Tomoaki Hinoue,
• Yoshitane Imai and
• Masahiro Miura

Beilstein J. Org. Chem. 2020, 16, 325–336, doi:10.3762/bjoc.16.32

• dehydrogenative coupling adopting oxygen atom as the linker [12][13][14][15][16][17]. In particular, bisbenzofuro[2,3-b:3′,2′-e]pyridines (BBZFPys) were found to exhibit intense photoluminescence with relatively high quantum efficiency (Φflu up to 0.70), indicating that the BBFZPy scaffold may serve as a key

• ’-binaphthyl backbone as precursors for the dehydrogenative coupling reaction (Scheme 2). In general, functionalization of the BINOL hydroxy groups should be performed at temperatures below 80 °C to prevent racemization [40][41]. 6,6’-Di-tert-butyl-1,1’-bi-2-naphthol (1) was treated with 2,6-difluoropyridine

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• , Luo’s group disclosed another potential application of integrating electrochemical oxidation with chiral amine catalysis [77]. Using chiral primary amine 130 as a catalyst, the authors reported an electricity-driven cross-dehydrogenative coupling of ketones 129 with tertiary amines 128. The

A metal-free approach for the synthesis of amides/esters with pyridinium salts of phenacyl bromides via oxidative C–C bond cleavage

• Kesari Lakshmi Manasa,
• Yellaiah Tangella,
• Namballa Hari Krishna and
• Mallika Alvala

Beilstein J. Org. Chem. 2019, 15, 1864–1871, doi:10.3762/bjoc.15.182

• ], rearrangement of aldoximes [18], hydration of nitriles [19], dehydrogenative coupling of primary alcohols with amines [20][21] and hydration of organonitriles to amides [22][23][24]. However, these traditional methods have certain disadvantages such as generation of toxic chemical waste, involvement of tedious

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• metal catalyst. Through a tandem three-component cross-dehydrogenative coupling (CDC), they prepared, in a single step, more than thirty isoindolinone derivatives 4, including those originated from sulfonamides and carboxamides (Scheme 1). The scope of the reaction includes aromatic, some aliphatic and

• with the nucleophilic aromatic ring in a Friedel–Crafts alkylation process, thus incorporating the carbon atom in a formal C(sp2)–H/C(sp3)–H cross-dehydrogenative coupling. Finally, an oxidation of sulfide 7 to sulfoxide 8 and the subsequent attack of amide 2 with cleavage of the C–S bond and formation

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• maximum contact (solvent-free ball milling) of the reactants [113]. An acid salt, (sodium bisulfate) was used to control the reactivity of the highly basic primary amines to transform the exceedingly exothermic reactive substrates in a high-yielding cross-dehydrogenative coupling (CDC) reaction to obtain

Molecular iodine-catalyzed one-pot multicomponent synthesis of 5-amino-4-(arylselanyl)-1H-pyrazoles

• Camila S. Pires,
• Daniela H. de Oliveira,
• Maria R. B. Pontel,
• Jean C. Kazmierczak,
• Roberta Cargnelutti,
• Diego Alves,
• Raquel G. Jacob and
• Ricardo F. Schumacher

Beilstein J. Org. Chem. 2018, 14, 2789–2798, doi:10.3762/bjoc.14.256

• -(phenylselanyl)-1H-pyrazol-5-amine was submitted to an oxidative dehydrogenative coupling to produce a diazo compound confirmed by X-ray analysis. Keywords: diaryl diselenide; diazo compound; 1H-pyrazole; molecular iodine; multicomponent reaction; Introduction Selenium-containing compounds are of great

Direct electrochemical generation of organic carbonates by dehydrogenative coupling

• Tile Gieshoff,
• Vinh Trieu,
• Jan Heijl and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2018, 14, 1578–1582, doi:10.3762/bjoc.14.135

• ; dehydrogenative coupling; electrochemistry; organic carbonates; Introduction Polycarbonates are high-performance polymeric materials with versatile applications in various fields with economic impact, e.g., construction, food, and pharmaceutical industry [1]. For their technical large-scale production, organic

• [28][29][30]. In combination with easily accessible carbonate sources, we tried to establish a new dehydrogenative approach to organic carbonates. Here, the study on the first direct electrochemical generation of organic carbonates by dehydrogenative coupling is presented. Results and Discussion

• potentials and the oligomerization tendency of electron-rich arenes limit the scope (see Supporting Information File 1). Conclusion The first direct electrochemical generation of organic carbonates by dehydrogenative coupling at arenes was established. Even though this ambitious method is currently

Polysubstituted ferrocenes as tunable redox mediators

• Sven D. Waniek,
• Jan Klett,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2018, 14, 1004–1015, doi:10.3762/bjoc.14.86

• dehydrogenative coupling reactions [34][35] and for olefin hydroamidations [36] (Scheme 1d–f). For potential applications of ferrocene derivatives as redox mediators or SET reagents, it is crucial to adjust the electrochemical potential to the potential of the substrate. The electrochemical potential of the

Functionalization of N-arylglycine esters: electrocatalytic access to C–C bonds mediated by n-Bu₄NI

• Mi-Hai Luo,
• Yang-Ye Jiang,
• Kun Xu,
• Yong-Guo Liu,
• Bao-Guo Sun and
• Cheng-Chu Zeng

Beilstein J. Org. Chem. 2018, 14, 499–505, doi:10.3762/bjoc.14.35

• . In addition, it is demonstrated that the mediated process is superior to the direct electrochemical functionalization. Keywords: C–C formation; electrochemical oxidative functionalization; n-Bu4NI; redox catalyst; Introduction The oxidative cross dehydrogenative coupling (CDC) of two C–H bonds has

• experiments described above, as well as related references [4], a plausible mechanism for the electrocatalytic cross dehydrogenative coupling of N-arylglycine esters 1 with C–H nucleophiles 2 is outlined in Scheme 6. The anodic oxidation of iodide generates the active species I2 or I+. Followed by a

• efficient electrocatalytic cross dehydrogenative coupling of arylglycine esters with C–H nucleophiles has been developed. This protocol employs simple n-Bu4NI as the redox catalyst, avoiding utilization of transition metals and excess amounts of external oxidant, thereby providing an environmentally benign

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• example of a double Sonogashira reaction is shown [60]. Oxidative cross-dehydrogenative coupling Copper-catalyzed mechanochemical oxidative cross-dehydrogenative coupling (CDC) reactions [61][62][63][64][65][66] of tetrahydroisoquinolines with alkynes and indoles was reported by Su and co-workers (Scheme

• bond synthesis under ball-milling conditions. Cross dehydrogenative coupling reactions between benzaldehydes and benzylamines were performed in presence of phenyliodine diacetate (PIDA) using the acid salt NaHSO4 [81]. The highly exergonic reaction (contact explosive) of acidic iodine(III) and basic

Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

• Santanu Hati,
• Ulrike Holzgrabe and
• Subhabrata Sen

Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162

• reacted with o-aminobenzylamine and substituted o-aminobenzylamines to provide the desired products in decent yields (Scheme 8b). Kumar et al. demonstrated transition metal-free α-C(sp3)–H bond functionalization of amines via an oxidative cross-dehydrogenative coupling reaction [44]. They reported a one

• to generate the desired substituted dihydroquinazolines 35 in moderate to excellent yields (Scheme 9) [44]. In another example commercially available sodium hypochlorite (NaOCl) was used as an oxidant, under mild conditions in a highly efficient oxidative dehydrogenative coupling of o

• quinazolinones with I2 and DDQ [37][38][39][40]. DDQ-mediated oxidative dehydrogenation of thiazolidines and oxazolidines. Oxone-mediated oxidative dehydrogenation of intermediates from o-phenylenediamine and o-aminobenzylamine [42][43]. Transition metal-free oxidative cross-dehydrogenative coupling. NaOCl