Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

• Tzu-Yu Huang,
• Mario Djugovski,
• Sweta Adhikari,
• Destinee L. Manning and
• Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

• gem-difluoroalkenes with organic azides in morpholine as a solvent to construct fully decorated morpholine-substituted 1,2,3-triazoles. Mechanistic studies revealed the formation of an addition–elimination intermediate of morpholine and gem-difluoroalkenes prior to the triazolization reaction via two

• ). We observed addition–elimination intermediate of morpholine and gem-difluoroalkenes INT-1, (−99.9 ppm, d, J = 35.7 Hz) within 30 min of the reaction and a gradual consumption of the gem-difluoroalkene 1 (−83.67 ppm, dd, J = 33.8, 26.4 Hz and −85.78, dd, J = 33.8, 3.8 Hz) throughout the course of 8 h

• –elimination of morpholine to gem-difluoroalkene 1 affording INT-1, which can generate product 3 via two routes (Figure 5). Route A entails the formation of an aminoalkyne intermediate, INT-2, which can participate in a [3 + 2] azide–alkyne cycloaddition to form the final product 3. Alternatively, vinylic

Unraveling the role of prenyl side-chain interactions in stabilizing the secondary carbocation in the biosynthesis of variexenol B

• Moe Nakano,
• Rintaro Gemma and
• Hajime Sato

Beilstein J. Org. Chem. 2023, 19, 1503–1510, doi:10.3762/bjoc.19.107

• as the C–H–π interaction between the carbocation intermediate and the Phe residue of terpene cyclase in the biosynthesis of sesterfisherol [21], and the intricated rearrangement reaction mechanism promoted by the equilibrium state of the homoallyl cation and the cyclopropylcarbinyl cation in the

• hyperconjugation determines whether the reaction proceeds in a stepwise or concerted manner. The second interesting aspect of the biosynthesis of variexenol B is that the biosynthetic pathway involves an intermediate with an exomethylene group. A terpene with an exomethylene group as a starting material is rare

• interacts with the secondary carbocation at C10, reducing the activation energy of the first step by approximately 4.7 kcal/mol. Moreover, due to the stabilization of the secondary carbocation-like intermediate IM2, the reaction proceeds stepwise rather than concertedly [7]. It was found that the final

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• of aryl sulfides by using the catalyst and the base. A catalytic cycle is shown in Scheme 4. Firstly, electrophilic Pd(TFA)2 generated from Pd(OAc)2 and TFA, which (by C–H functionalization of arene 4) led to intermediate II. Oxidative insertion of intermediate II into the N–S bond of 1 afforded

• intermediate III. Reductive elimination of Pd from III gave product 5 and species IV. Finaly, Pd(II) species were reproduced by ligand exchange to restart the next cycle (Scheme 4). In 2014, Fu and co-workers described a facile method for the C–H thiolation of phenols 7 with 1-(substituted phenylthio

• sulfur atom to Fe3+ to generate Fe2+ and radical cation I. Subsequent cleavage of the N–S bond led to cation II and radical III. Interaction of III with Fe2+ regenerated the Fe3+ species and IV. At the same time, electrophilic addition of II to alkene 9 yielded intermediate V, which was subjected to the

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• =CHC(=O)Me] with arenes in Brønsted superacid TfOH (triflic acid, CF3SO3H) furnishes 3-methyl-1-trichloromethylindenes (Scheme 1a) [11]. Based on NMR analysis in TfOH and theoretical DFT calculations, it has been found that the reaction proceeds through an intermediate formation of the O-protonated

• , electrophilic properties of atom C3 should be mainly explained by orbital factors, rather than charge ones. Summarizing the data obtained during the synthesis of indanones 3 (Scheme 5, Scheme 6 and Table 1), NMR, and DFT studies on intermediate cations (Table 2 and Table 3), one may propose plausible reaction

• (1-aryl-4,4,4-trichlorobut-2-en-1-ones) and CCl3-hydroxy ketones (1-aryl-4,4,4-trichloro-3-hydroxybutan-1-ones) in Brønsted superacid TfOH at an elevated temperature of 80 °C within 2–18 h. In both cases, the reaction proceeds through an intermediate formation of the O-protonated carbonyl form of the

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• enolate and a new R• that propagates the radical chain (Scheme 1). Initiation occurs upon oxidation of the dialkylzinc reagent by oxygen. The feasibility of such 1,4-addition reactions is fully reliant on the ease of the intermediate enoxyl radical to undergo alkylzinc-group transfer. Secondary α-carbonyl

• benefit from a similar effect, even though in this case, the direct formation of an intermediate enolate remains uncertain [11]. With this context in mind, we surmised that β-aminoenoates I could be suitable 1,4-acceptors (Scheme 2, bottom). We previously reported tandem reactions of such substrates

• wherein the intermediate enoxyl radical II arising from the addition step evolves via intramolecular addition to tethered alkenes [16][17] or alkynes [18]. We wondered if, in the absence of the pending radical acceptor, the presence of the β-nitrogen atom could nevertheless promote zinc enolate formation

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• primary, secondary, and tertiary alkyl halides. The mechanistic investigation revealed the generation of a silyl–copper intermediate which activates the alkyl halides by a single electron transfer to form alkyl radical intermediates [54]. It was suggested that substituting B2pin2 for PhMe2Si-Bpin would

• (I) complex at the β-carbon atom of the activated C=C bond thereby catalyzing the reaction. The NHC–Cu(I) complexes have been found to be effective catalysts for conjugate addition reactions because they stabilize the intermediate species involved in the reaction, which can otherwise be highly

• activation to generate an aryl–Cu–NHC species. This is followed by the reaction with NHC–Pd to produce an Ar–Pd(NHC)Cl intermediate through the oxidative addition to Pd(0)NHC. Finally, transmetallation of [(It-Bu)Cu(Ar)] with [(SIPr)Pd(Ar)Cl] followed by reductive elimination leads to biaryl product. No

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• benzyl azide 3 in situ from benzyl bromide (5) and sodium azide and to directly trap the intermediate with alkyne 2. Under conditions summarized in reaction 3 of Scheme 2 we obtained the desired 1,2,3-triazole derivative 3 in 82% yield. Copper(II) sulfate pentahydrate (0.07 equivalents based on 2) in the

• ), respectively, in the presence of sodium azide and alkyne 2 (Scheme 4). The conditions employed above converted the meta-substituted dihalide into the expected symmetric bis(1,2,3-triazole) derivative 9 in very good yield, but we also isolated azide 10 in small quantities, where the intermediate biazide has

• allowed to lower the reaction temperature from 60 °C to 40 °C, but it also induced full consumption of the intermediate biazide derived from dihalide 11 (Scheme 4, reaction 3); 0.2 equiv of copper(II) sulfate pentahydrate, 0.4 equiv of sodium ascorbate and 0.4 equiv of ʟ-proline in very little of

Functional characterisation of twelve terpene synthases from actinobacteria

• Anuj K. Chhalodia,
• Houchao Xu,
• Georges B. Tabekoueng,
• Binbin Gu,
• Kizerbo A. Taizoumbe,
• Lukas Lauterbach and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1386–1398, doi:10.3762/bjoc.19.100

• as plasticisers. A) Cope rearrangement of 24 and 26. B) Cyclisation mechanism from FPP to 23, identifying compound 26 as a biosynthetic intermediate and 24 as a side product. Terpene synthase homologs characterised in this study. Supporting Information Supporting Information File 162: Additional

Consecutive four-component synthesis of trisubstituted 3-iodoindoles by an alkynylation–cyclization–iodination–alkylation sequence

• Nadia Ledermann,
• Alae-Eddine Moubsit and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2023, 19, 1379–1385, doi:10.3762/bjoc.19.99

• transition-metal catalysis [31], we disclosed an activating group-free alkynylation–cyclization sequence to (aza)indoles [32][33] that could be readily concatenated with a concluding N-alkylation of the 7-azaindole intermediate in the sense of consecutive three-component coupling–cyclization–alkylation

• nitrogen protection or activation using KOt-Bu in DMSO as a base. Under these conditions, the formation of the terminal (aza)indole anion is the driving force (Scheme 1) [34]. As a consequence, the electrophilic trapping of this intermediate with alkyl halides provides as concise access to N-substituted

• summary the indole anion intermediate resulting from a one-pot alkynylation–cyclization sequence, which has been previously shown to be efficiently trapped by carbon electrophiles to give N-substituted indoles in a consecutive three-component synthesis, can be selectively iodinated in the 3-position with

Visible-light-induced nickel-catalyzed α-hydroxytrifluoroethylation of alkyl carboxylic acids: Access to trifluoromethyl alkyl acyloins

• Feng Chen,
• Xiu-Hua Xu,
• Zeng-Hao Chen,
• Yue Chen and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2023, 19, 1372–1378, doi:10.3762/bjoc.19.98

• pivalic anhydride as activator to afford Ni(II) intermediate F. Subsequently, trapping of the alkyl radical C generates high-valent Ni(III) intermediate G, which undergoes facile reductive elimination to furnish the final coupling product 3 and Ni(I) intermediate H. The single-electron transfer (SET

• ) reduction of intermediate H (Ered(NiI/Ni0) = −1.17 V vs SCE [41]) by photoexcited HE* (Ered(HE*/HE·+) = −2.28 V vs SCE [42]) regenerates the active Ni(0) species E and closes the catalytic cycle. Conclusion In conclusion, we have demonstrated a visible-light-induced nickel-catalyzed radical cross coupling

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• tosylation of the primary alcohol produced 4.8. The epoxidation of 4.8 occurred by reaction with t-BuOK in THF, thus producing 4.9 as a chiral electrophile. The regioselective opening of the epoxide is achieved by adding the octadecanol sodium salt. The intermediate was debenzylated by catalytic

• oxidation with Br2 and hydrolysis, the bromoethyl phosphate 5.4. Finally, the quaternarization with trimethylamine produced 5.5 and the acetylation produced 5.6 PAF. The intermediate compounds like 6.2 (1-O-alkylglycerol) or the protected secondary alcohol 6.6, either as enantiopure or racemic forms, are

• intermediate 6.3 (ᴅ- or ʟ-threitol) that was then alkylated with mesityl lipid alcohol to produce 6.4 [80][81]. The acetal protecting group was removed in acidic conditions and then the intermediate 6.5 was subjected to oxidative cleavage to yield an aldehyde that was reduced with NaBH4 to produce 6.6a,b

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

• oxidant to generate an oxygen-radical cationic intermediate, which undergoes abstraction of a hydrogen radical (or loses a proton first, followed by an electron) to afford an oxonium ion intermediate. Finally, the oxonium ion is attacked by various nucleophiles to obtain the target functionalized product

• oxidative alkylation of cyclic benzyl ethers with malonates or ketones. Oxygen is used as a terminal oxidant at atmospheric pressure. The key intermediate of this oxidative coupling reaction is benzyl alcohol intermediate C (Scheme 4) [52]. The generation of N–O radicals from NHPI in the presence of oxygen

• -methylisochroman, 3-methoxyanisole). Mechanism experiments showed that the coupling of aromatic ring radicals with ether oxygen ions produced an intermediate radical cation, which achieves a catalytic cycle through the Cu center. Lee et al. disclosed TBHP as an oxidant and Pd(OAc)2/Cu(OTf)2 as the catalyst to

Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

• Olfa Mhasni,
• Jalloul Bouajila and
• Farhat Rezgui

Beilstein J. Org. Chem. 2023, 19, 1251–1258, doi:10.3762/bjoc.19.93

• alcohols 4, such as 4a, starts with a conjugate addition of imidazole (2a) at the C-β position of the Michael acceptor 4a, followed by elimination of the hydroxy moiety, affording the intermediate I. Similarly, a further second β’-conjugate addition of imidazole (2a) to I might occur, followed by

• elimination of imidazole (2a) finally providing the allylated derivative 6a (Scheme 2) [24][25][26][31]. It is notable, that such reaction mechanism involving the intermediate I was previously explored by Smith [32] and supported by studies of Tamura [33]. Next, in order to explore the scope of the above

Acetaldehyde in the Enders triple cascade reaction via acetaldehyde dimethyl acetal

• Alessandro Brusa,
• Debora Iapadre,
• Maria Edith Casacchia,
• Alessio Carioscia,
• Giuliana Giorgianni,
• Giandomenico Magagnano,
• Fabio Pesciaioli and
• Armando Carlone

Beilstein J. Org. Chem. 2023, 19, 1243–1250, doi:10.3762/bjoc.19.92

• process. The ingenious crafting of the reaction lies in the selection of the reactivity of the different nucleophiles and electrophiles present in the mixture, both as reagents and as intermediates. First, the chiral aminocatalyst 1 activates the saturated aldehyde 2 via enamine intermediate A, which

• intercepts the nitroalkene 3 in a Michael-type addition forming intermediate B. Hydrolysis regenerates catalyst 1 that can then selectively condense with the α,β-unsaturated aldehyde 4 to form chiral iminium ion intermediate C. Iminium ion C reacts with intermediate B in a further Michael-type reaction. The

• last step involves the enamine intermediate which drives an intramolecular aldol condensation to form the final product 5. In this elegant cascade process, catalyst 1 promotes three consecutive carbon–carbon bond forming steps generating four stereogenic centers with high diastereoselectivity and

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• ), in which the in situ-generated adduct of thiophenol and 3-phenacylideneoxindole was believed to be the key intermediate [53][54][55]. Inspired by these elegant synthetic protocols and in continuation of our aim to develop convenient reactions for the synthesis of diverse spiro compounds [56][57][58

• meantime, the condensation of isatin 2 with ammonium acetate gave the 3-iminoisatin intermediate A. Secondly, Michael addition of the in situ-generated carbanion of the 3-isatyl-1,4-dicarbonyl compound 1 to 3- iminoisatin A gave intermediate B. In the case of intermediate B1 with an ethoxycarbonyl group

• , the nucleophilic addition of the amino anion to the carbonyl group in the of 1,3-cyclohexanedione scaffold resulted in cyclic intermediate C. Thirdly, the elimination of water from intermediate C gave the isolated product 3. In the case of the intermediate B2 with a benzoyl group, there are two kinds

Radical ligand transfer: a general strategy for radical functionalization

• David T. Nemoto Jr,
• Kang-Jie Bian,
• Shih-Chieh Kao and
• Julian G. West

Beilstein J. Org. Chem. 2023, 19, 1225–1233, doi:10.3762/bjoc.19.90

• overcome the challenges faced by other strategies (Scheme 1). At its core, RLT involves the outer sphere transfer of an anionic, X-type ligand coordinated to a redox-active metal to a radical intermediate, resulting in formation of a new C–ligand bond with concomitant single electron reduction of the metal

• form new C–Cl bonds in the presence of transient alkyl radicals, with mechanistic studies implicating homolytic abstraction of a chlorine ligand from the intermediate copper complex. Outside of the substitution products which could be generated from the RLT pathway, alkyl radicals could also undergo an

• intermediate. RLT to this radical from another azide ligand leads to a diazidated product. The overall scope of both reports suggests that the diazidation of simple to complex drugs/natural product-derived alkene substrates is readily achievable, including highly substituted and cyclic aliphatic alkenes

Unravelling a trichloroacetic acid-catalyzed cascade access to benzo[f]chromeno[2,3-h]quinoxalinoporphyrins

• Chandra Sekhar Tekuri,
• Pargat Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2023, 19, 1216–1224, doi:10.3762/bjoc.19.89

• beginning of the reaction, copper(II) 2,3-diamino-5,10,15,20-tetraarylporphyrins 1 react with 2-hydroxynaphthalene-1,4-dione (2) in the presence of trichloroacetic acid to form an imine intermediate which on intramolecular cyclization affords a key benzo[f]quinoxalinoporphyrin intermediate 17. Further, a

• condensation of intermediate 17 with 2-arylidene-5,5-dimethylcyclohexane-1,3-dione 18 (formed in situ through an Aldol condensation of aldehydes with dimedone), to generate copper(II) benzo[f]chromeno[2,3-h]dihydroquinoxalinoporphyrins which on dehydration produce the desired copper(II) benzo[f]chromeno[2,3-h

• . After workup and chromatographic purification, the isolated product was characterized based on spectral data analysis as copper(II) benzo[f]quinoxalinoporphyrin intermediate 17. Further, porphyrin 17 reacted with benzaldehyde and dimedone in chloroform containing 20 mol% trichloroacetic acid at 65 °C to

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• that [CpRh(bpy)(H2O)]2+ could slowly produce formate, a key biocatalytic intermediate, in the absence of the enzymes but they validated their system by proving that overall the formate production and conversion to methanol by the biocatalytic enzyme cascade far outcompeted any side-reactions. Ishitani

• reduction consumed the sacrificial donor methanol to form formic acid and formaldehyde [56]. This system is interesting for a number of reasons. Rather than intermediate redox mediators shuttling charge between two photocatalytic assemblies, Ishitani, Domen, and co-workers covalently connected the catalytic

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• have been feasible. In 1989, Moriarty was investigating the intramolecular cyclopropanation of 10 under copper-catalysis, presuming that the reaction would proceed through a metallocarbene intermediate [113]. However, a control experiment showed the reaction to also be viable without catalyst, from

• , they believed that the reaction was likely initiated by either single electron transfer between the reagents (not shown), or by electrophilic addition of the olefin onto the ylide, forming intermediate adduct 17. This was followed by formation of iodocycle 18, from which reductive elimination of

• intermediate was not viable under such mild conditions. The initially proposed ionic pathway (Figure 5, left) was abandoned as solvent effects had little influence on the reaction rate, and since no Wagner–Meerwein rearrangement products were detected with bicyclic olefin precursors. Radical-based pathways

New one-pot synthesis of 4-arylpyrazolo[3,4-b]pyridin-6-ones based on 5-aminopyrazoles and azlactones

• Vladislav Yu. Shuvalov,
• Ekaterina Yu. Vlasova,
• Tatyana Yu. Zheleznova and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2023, 19, 1155–1160, doi:10.3762/bjoc.19.83

• are also low in two-stage synthesis methods. The first of them is based on the three-component condensation of aminopyrazoles, Meldrum's acid, and aromatic aldehydes, followed by the oxidation of the intermediate with DDQ [13][16][19] (method B). The second one includes the reaction of an aromatic

• carried out as one-pot synthesis, without isolation of the intermediate dihydro derivative 3а. In this case, the solvent (DMSO) could be added at the stage of obtaining dihydro derivative 3a or introduced into the reaction together with t-BuOK. We have explored both variants. When intermediate 3a was

• -aminopyrazoles 1, 5, 6 and azlactones 2a–i, followed by heating the resulting intermediate in DMSO in the presence of t-BuOK. Photophysical properties of the obtained compounds were studied. Biologically active 4-arylpyrazolo[3,4-b]pyridin-6-ones. Normalized absorption and fluorescence spectra of solutions of

Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• nucleophilic attack by water. The superoxide first abstracts a proton to form the perhydroxyl radical VII followed by hydrogen atom abstraction from intermediate VIII to yield sulfoxide IX. The generated hydrogen peroxide decomposes into water and oxygen. The novel proposed pathway can either be dominant or

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

• intermediate is proposed in conPET and PEC reactions (e.g., a photoexcited radical anion), yet different reactivity outcomes arise; the underlying reasons for such are discussed. Finally, we provide our perspective on current challenges and target areas for future exploration. 1.1 Multi-photon processes As

• catalyst intermediate, the same catalyst can in principle be repurposed for either technique, and mechanistic learnings will thus be highly transferrable between the fields. Although asymmetric transformations are yet to be achieved using conPET, the PEC section of this Review will also describe pioneering

• neutral PDI and forms the aryl halide’s radical anion, which then undergoes C(sp2)–X bond fission to afford the aryl radical as a reactive intermediate. The aryl radical then either reacts via hydrogen atom transfer (HAT) with solvent molecules or Et3N•+ in an overall dehalogenation to furnish product 2

Synthesis of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines via a base-induced rearrangement of functionalized imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazines

• Dmitry B. Vinogradov,
• Alexei N. Izmest’ev,
• Angelina N. Kravchenko,
• Yuri A. Strelenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2023, 19, 1047–1054, doi:10.3762/bjoc.19.80

• to that of the transformation of structure 1a (81%). Salt 3j was isolated in 44% yield. The absence of signals of the starting or intermediate compounds in the 1H NMR spectrum of the reaction mixture (for 3c,d) also indicates the complete conversion of esters 2c,d to the potassium salts 3c,d after 4

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• TADF was observed. This is a solid experimental evidence that spin–vibronic coupling is essential for TADF, and the 3CS → 1CS rISC is slow, without the coupling with the intermediate 3LE state. The conventionally used transient luminescence spectral method is unable to supply such in-depth mechanistic

Copper-catalyzed N-arylation of amines with aryliodonium ylides in water

• Kasturi U. Nabar,
• Bhalchandra M. Bhanage and
• Sudam G. Dawande

Beilstein J. Org. Chem. 2023, 19, 1008–1014, doi:10.3762/bjoc.19.76

• generation of carbene as a reactive intermediate [36][37]. Also, spirocyclic iodonium ylides have been used for radiolabeling techniques [38]. In 2013, Shibata’s research group reported a novel trifluoromethanesulfonyl iodonium ylide for trifluoromethylthiolation of enamines, indoles, and ketoesters

• , catalyzed by a copper catalyst [39]. Murphy and co-workers reported blue LED-mediated metal-free cyclopropanation of alkenes with iodonium ylides through a diradical intermediate [40]. However, iodonium ylides are relatively unexplored for the arylation of amines. So far only Spyroudis’s group reported N