Three-component N-alkenylation of azoles with alkynes and iodine(III) electrophile: synthesis of multisubstituted N-vinylazoles

• Jun Kikuchi,
• Roi Nakajima and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2024, 20, 891–897, doi:10.3762/bjoc.20.79

• difunctionalization of alkynes with various heteroatom and carbon nucleophiles [27][28][29][30][31][32][33][34]. Specifically, intermolecular trans-iodo(III)functionalization of alkynes has been achieved using oxygen nucleophiles such as alcohols [28][32], ethers [33], carboxylic acids [31], phosphate esters [31

• ], and sulfonic acids [31]. On the other hand, nitrogen-based nucleophiles amenable to this reaction manifold have thus far been limited to nitriles in the context of Ritter-type iodo(III)amidation [29]. In light of the significance of vinylated azoles, our attention was attracted to the feasibility of

• various azole nucleophiles including pyrazole, indazole, 1,2,3-triazole, benzotriazole, and tetrazole. The follow-up transformation of the iodanyl group provides a means to prepare hitherto inaccessible types of alkenylated azoles. Further exploration of the three-component alkenylation of nitrogen and

Ortho-ester-substituted diaryliodonium salts enabled regioselective arylocyclization of naphthols toward 3,4-benzocoumarins

• Ke Jiang,
• Cheng Pan,
• Limin Wang,
• Hao-Yang Wang and
• Jianwei Han

Beilstein J. Org. Chem. 2024, 20, 841–851, doi:10.3762/bjoc.20.76

• -benzocoumarin skeletons in the presence of palladium catalysts (Scheme 1b). Furthermore, Olofsson and colleagues described an unprecedented reaction pathway using ortho-fluoro-substituted diaryliodonium salts bearing strong electron-withdrawing groups, leading to novel diarylations of N-, O-, and S-nucleophiles

Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions

• Martyn Jevric,
• Julian Klepp,
• Johannes Puschnig,
• Oscar Lamb,
• Christopher J. Sumby and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2024, 20, 823–829, doi:10.3762/bjoc.20.74

• at C4 determined the resultant ring system, as the σ* orbital is not accessible to external nucleophiles due to steric hindrance and the rigid conformation of the bicyclic ring system. When the C4–OH was equatorial, O8 migrated as it was aligned with the σ* orbital giving a 3,8-dioxabicyclo[3.2.1

Advancements in hydrochlorination of alkenes

• Daniel S. Müller

Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72

• conclusion we wish to point out that this reaction provides a convenient procedure to achieve anti Markovnikov addition of alcohols to olefins which can presumably be extended to other systems. Furthermore, the addition of other nucleophiles to photochemically generated cation radicals would make this type

Synthesis of new representatives of A₃B-type carboranylporphyrins based on meso-tetra(pentafluorophenyl)porphyrin transformations

• Victoria M. Alpatova,
• Evgeny G. Rys,
• Elena G. Kononova and
• Valentina A. Ol'shevskaya

Beilstein J. Org. Chem. 2024, 20, 767–776, doi:10.3762/bjoc.20.70

• biomolecules via the nucleophilic aromatic (SNAr) substitution reactions [15][16]. A variety of nucleophiles such as amines [17][18], alcohols [18][19][20], thiols [17][19][21][22][23], and carboranes [17][24][25][26][27] have been studied in selective SNAr substitution reactions of the p-fluorine atoms in

• next studied the modification of the pentafluorophenyl substituents with carborane clusters via the SNAr substitution reaction with carborane nucleophiles [17][24][25][26][27]. These reactions are well studied for porphyrin 1 [17][24][25][26][27] to afford the corresponding carborane derivatives

• the SNAr substitution reactions with 9-mercapto-m-carborane. As a result, tris(carboranyl)-substituted porphyrins containing pentafluorophenyl- or p-aminotetrafluorophenyl-substituents were synthesized and used in the reactions with a variety of thio- or amino-nucleophiles to form functionalized

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

• Senze Qiao,
• Zhongyu Cheng and
• Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

• polyketides or peptides, and form an ester bond. Then, they catalyze either intramolecular macrocyclization to give macrolactones or macrolactams with attacking of internal nucleophiles (alcohols or amine), or hydrolysis to release linear acids or peptides (Scheme 1b). Although TE domains may display

Regioselective quinazoline C2 modifications through the azide–tetrazole tautomeric equilibrium

• Dāgs Dāvis Līpiņš,
• Andris Jeminejs,
• Una Ušacka,
• Anatoly Mishnev,
• Māris Turks and
• Irina Novosjolova

Beilstein J. Org. Chem. 2024, 20, 675–683, doi:10.3762/bjoc.20.61

• explanation for the present tetrazole form in the solutions. Surprisingly, FTIR and X-ray analyses of 12a in the solid state indicated the existence of 12a in the azide form. In subsequent experiments it was discovered that for less nucleophilic N-nucleophiles (piperidine, morpholine, N-methylpiperazine) C2

Palladium-catalyzed three-component radical-polar crossover carboamination of 1,3-dienes or allenes with diazo esters and amines

• Geng-Xin Liu,
• Xiao-Ting Jie,
• Ge-Jun Niu,
• Li-Sheng Yang,
• Xing-Lin Li,
• Jian Luo and
• Wen-Hao Hu

Beilstein J. Org. Chem. 2024, 20, 661–671, doi:10.3762/bjoc.20.59

• electrophilic trapping of onium ylides generated from metal carbenes with nucleophiles, providing an ingenious difunctionalization strategy for diazo compounds to access structurally complex and diverse molecules (Scheme 1b, top) [28][29]. In recent years, radical-mediated MCRs with diazo compounds have become

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• the corresponding =CF2 containing products [10]. In addition to complexes of aluminum and boron, several magnesium and lithium silyl reagents were prepared and proved to be good nucleophiles in reactions with (Z)-1,1,1,4,4,4-hexafluorobut-2-ene, as a result of which the corresponding

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• activation of NHPI esters under a photocatalytic oxidative quenching mechanism was reported for the first time by Glorius and co-workers in 2017 [46]. This activation mode was applied in the functionalization of styrenes using an Ir-photocatalyst and a diverse range of nucleophiles that are H-bond donors

• oxyalkylation product 28. Li and co-workers described the activation of NHPI esters towards SET using a Lewis acid catalyst, allowing for the functionalization of styrene radical acceptors with nucleophiles that do not necessarily engage in hydrogen-bonding interactions, such as electron-rich (hetero)arenes [47

• . Intramolecular radical addition into the radical cation of the furan ring would then form cation 50 before nucleophilic capture by H2O leads to product 45. In 2020, the Wang group reported the functionalization of enamides employing radicals derived from NHPI esters in combination with indole nucleophiles [57

Nucleophilic functionalization of thianthrenium salts under basic conditions

• Xinting Fan,
• Duo Zhang,
• Xiangchuan Xiu,
• Bin Xu,
• Yu Yuan,
• Feng Chen and
• Pan Gao

Beilstein J. Org. Chem. 2024, 20, 257–263, doi:10.3762/bjoc.20.26

• ]. Recently, Ritter and co-workers reported that alkylthianthrenium salts can be employed to undergo reactions with N/O-nucleophiles under photocatalytic conditions [46]. Nevertheless, additional transition metal catalysts, visible light, or electrochemical devices are required for the reported works

• . Therefore, developing a green method to functionalize alkylthianthrenium salts is still highly desirable. Considering the highly polarized C(sp3)–S bond in alkylthianthrenium salts, alkylthianthrenium salts have the potential to serve as alkyl electrophiles to react with nucleophiles directly in the absence

• using nucleophiles directly, without the need for an external metal catalyst. Synthetic application of thianthrenium salts. Substrate scope. Reaction conditions: alkylthianthrenium salts 1 (0.3 mmol), thiophenols 2 (0.2 mmol), DIPEA (0.4 mmol) in 2.0 mL of MeCN at room temperature for 16 h under air

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• equilibrium) under the action of an excess of nucleophiles as bases. Such dianions are characteristic of acenaphthene and have been repeatedly detected in subsequent transformations [18][19]. In our case, the CH-acidity of the CH2CH2 bridge should be even higher under the action of pyridine rings, and, if

• dianion 7 forms (resonance form 7b will prevail in this case, Figure 1), it will be inactive to attack by nucleophiles. The behavior of acenaphthene 5 could be clarified further using its naphthalene analog 3, which lacks benzylic CH2 protons, but there is no information in the literature about its

Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

• Viktoria A. Ikonnikova,
• Cristina Cheibas,
• Oscar Gayraud,
• Alexandra E. Bosnidou,
• Nicolas Casaretto,
• Gilles Frison and
• Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

• are excellent substrates for such reactions, affording electrophilic carbonyl derivatives susceptible to react with nucleophiles in the acidic reaction mixture [4][5][6][7][8]. Consequently, the Hock rearrangement is likely to be part of tandem processes involving this carbonyl function [9][10][11

• podophyllotoxin structure [26]. However, other nucleophiles like 20–27 (Scheme 5) were unsuccessful, only leading to complex mixtures or occasionally to small amounts of 4 (<10%). Finally, other homologous substrates were tested. While the tandem reaction with a phenylethyl substituent (n = 2, not shown) only led

• surrogate of the aldehyde function when it is engaged in a tandem photooxygenation and Hock rearrangement, involving allylic hydroperoxide intermediates in an acidic medium. In the presence of aromatic nucleophiles, the aldehyde intermediate of the Hock rearrangement can be involved in tandem Friedel–Crafts

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• positioning of the [2 + 2] CA or RE step as the rate-determining step may depend upon the structural attributes of the electrophiles and nucleophiles. In 2023, Nielsen et al. conducted an exhaustive kinetic analysis of the [2 + 2] CA–RE reaction involving 4-trimethylsilylethynylaniline and TCNE by leveraging

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• this zwitterion formation is of great importance since it is the initiation step for the catalytic cycle in Michael reactions [8]. Generally, the conjugate addition is favored for strong nucleophiles, which is why electron-rich trialkylphosphines were among the first catalysts used in this type of

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• AMYs B1 which then were reacted with nucleophiles to form C–H-functionalized pyrrolidines or subjected to the 1,3-dipolar cycloaddition with olefins to afford bicyclic compounds (Scheme 2A and B) [59][60]. We employed cyclic amines for the synthesis of spirooxindole-pyrrolidines 7a or 7b in good

Synthesis of 7-azabicyclo[4.3.1]decane ring systems from tricarbonyl(tropone)iron via intramolecular Heck reactions

• Aaron H. Shoemaker,
• Elizabeth A. Foker,
• Elena P. Uttaro,
• Sarah K. Beitel and
• Daniel R. Griffith

Beilstein J. Org. Chem. 2023, 19, 1615–1619, doi:10.3762/bjoc.19.118

• no improvement over the previously optimized conditions (Table 1, entry 8). Having established an efficient route to our desired azabicycle from tropone, we sought to employ additional amine nucleophiles bearing pendant vinyl iodides to access several analogs of product 4 (see Supporting Information

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

• , organic azides, and morpholine. Terminal gem-difluoroalkenes exhibit unique reactivity toward nucleophiles. The two σ-withdrawing fluorine atoms at the α-position and the strong polar nature of the double bond make gem-difluoroalkenes susceptible to a nucleophilic attack that is followed by a β-fluoride

• to access a set of fully decorated 1,2,3-triazoles. Functionalization of gem-difluoroalkenes with 1,3-dipoles and N-nucleophiles. Substrate scope. Reaction conditions: 1 (1 equiv), 2 (1.5 equiv) 0.4 equiv of LiHMDS (1 M in THF), morpholine (0.34–0.4 M), 75 °C, 48 h. Isolated yields are reported. a1

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

• field of organic synthesis. These compounds are readily accessible, safe, and more stable than toxic, unstable, and foul-smelling thiols. These electrophilic sulfur sources have deserved particular interest for the C–S bond formation via the reaction with various nucleophiles. Their preparation is

• -chlorosuccinimide in MeCN at room temperature for 20 min. N-Thiohydroxysuccinimide esters were obtained in up to high yields (21–83%). In the next phase, they performed the reaction of NTSEs with different nucleophiles, according to hard acyl and soft acylthio electrophilic sites contained in the NTSEs to

• selectively transfer the acyl or acylthio moieties. Arylboronic acids 74 and amines 76 were suitable for the acyl transfer and led to ketones 78 and amides 80 as the desired products. While, Grignard reagents 75 and thiols 77 acted as soft nucleophiles and resulted in thioesters 79 and acyl disulfides 81

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

• primary amines 1–3 with methyl α-(bromomethyl)acrylate was contemplated first under several typical conditions that all afforded non-synthetically useful mixtures of mono- and diallylation, even if excess of the nitrogen nucleophiles was used. An alternative strategy was thus developed relying on the

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

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

• reactions. Although the range of substrates for different C–H nucleophiles remains restricted, in recent years, copper-catalyzed oxidative coupling reactions between different C–H nucleophiles have been established. There are several common valence changes of copper in the catalytic process [44][45][46][47

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

• various nucleophiles, including C- and heteronucleophiles, such as compounds bearing –OH, –SH, and –NH groups [4][5][6][7]. Among them, the carbon–nitrogen bond formation through N-nucleophilic substitution reactions plays a central role for the synthesis of numerous compounds exhibiting various

• , the use of DABCO, commonly used as a powerful catalyst or a nucleophilic additive in the reaction of acyclic MBH adducts with various nucleophiles [21][34][35][36][37], did not afford the SN2/SN2’ products but provided the 1,4-adduct 8a in 84% yield (Table 2, entry 4). Alternatively, we also

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