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

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

• to changes in an ylide’s UV–vis absorption profile, or to its overall basicity or nucleophilicity, both of which could lead new and unexpected reactivity. The first example that specifically invoked electron donor–acceptor complexes of iodonium ylides was reported in 2018 by Wang and co-workers [122

• also have improved the nucleophilicity of the carbanion (see 52, Figure 11), facilitating the initial metallocarbene forming event. In 2019, Takemoto et al. investigated ortho-groups as a means to enhance the stability and solubility of ylide precursors, and they envisioned how blocking one of iodine’s

Linker, loading, and reaction scale influence automated glycan assembly

• Marlene C. S. Dal Colle,
• Manuel G. Ricardo,
• Nives Hribernik,
• José Danglad-Flores,
• Peter H. Seeberger and
• Martina Delbianco

Beilstein J. Org. Chem. 2023, 19, 1015–1020, doi:10.3762/bjoc.19.77

• ]. We wondered whether different glycan sequences were more sensitive to the linker structure. Less reactive donors might highlight differences in the linker nucleophilicity [25]. The aggregation of the growing glycan chains is conceivable to be connected to linker flexibility [18]. The efficiency of UV

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• in 83 and the enantioregulation was achieved by BINOL-derived chiral phosphoric acid P22. An amine functionality was crucial in the isoxazole ring to enhance the nucleophilicity of the adjacent carbon atom. In addition, the amine hydrogen forms an H-bond with the catalyst along with another hydrogen

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• expensive reagents and also has numerous applications in other areas of research. In this study, it was discovered that amines with less nucleophilicity also produced good yields of the product. In contrast, for the reaction with polyaromatic amines, THF was found to be the best solvent because these

Sulfate radical anion-induced benzylic oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines

• Joydev K. Laha,
• Pankaj Gupta and
• Amitava Hazra

Beilstein J. Org. Chem. 2023, 19, 771–777, doi:10.3762/bjoc.19.57

• condensation of aromatic aldehydes and sulfonamides (Scheme 1a) [3][5][6][7][8]. Because of the poor nucleophilicity of sulfonamides, the condensation reactions generally require harsh reaction conditions involving the use of strong acids, elevated temperature, and metal catalysts. Other methods include a non

• corresponding N-heterocycles 4c–f were obtained in good to moderate yield. However, the reaction with 2-aminophenol did not give the corresponding cyclized product 4g. This could be possibly due to the poor nucleophilicity of the ortho-OH group in 2-aminophenol thereby restricting the intramolecular

Nucleophile-induced ring contraction in pyrrolo[2,1-c][1,4]benzothiazines: access to pyrrolo[2,1-b][1,3]benzothiazoles

• Ekaterina A. Lystsova,
• Maksim V. Dmitriev,
• Andrey N. Maslivets and
• Ekaterina E. Khramtsova

Beilstein J. Org. Chem. 2023, 19, 646–657, doi:10.3762/bjoc.19.46

• . Such a change in the reaction selectivity could be explained by the influence of a higher nucleophilicity of the examined alkylamines in comparison with benzylamine. Then, we tried to involve less nucleophilic amines to the proposed approach. For these, we examined a reaction of APBTT 1a with aniline

• nucleophilicity of the amine. Then, we examined the proposed approach to PBTAs by involving bulky nucleophilic compounds 16a–d to the reaction with APBTT 1a. Unexpectedly, product 17a was formed instead of the anticipated PBTA C (Scheme 20). Compound 17a was formed in good isolated yields (60–70%) and was

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• polymerization, we suppose that a rapid termination and chain transfer reaction occurs during the MeOx polymerization. According to the chain transfer mechanism introduced by Litt et al., MeOx acts as a base and abstracts a proton from the polymer side chain [45]. Due to the slightly increased nucleophilicity

Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry

• Eric Gayon,
• Guillaume Lefèvre,
• Olivier Guerret,
• Adrien Tintar and
• Pablo Chourreu

Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15

• alkoxides exhibit strong σ-donating properties, given the high nucleophilicity of the alkoxide moiety. Moreover, the beneficial effect of molecular σ-donating additives on the yields and selectivities of iron-mediated cross-coupling reactions had already been reported in the literature. Nakamura thus

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

• Bilge Banu Yagci,
• Selin Ezgi Donmez,
• Onur Şahin and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

• group of intermediate 8 is expected to be more nucleophilic than that of intermediate 28 given the fact that allylsilanes possess a significantly higher nucleophilicity than vinylsilanes [69]. Therefore, the electron richness of the nucleophilic alkene appears to be an important parameter in addition to

• though the nucleophilicity of the allylsilane is expected to be low due to the presence of the electron-withdrawing acyl chloride functionality (pathway II, Scheme 8a). The subsequent lactam formation in intermediate 35 would give the final product 7. While general reactivity considerations and the

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• drastically the radical stability, nucleophilicity, and selectivity of 139 [73]. Furnishing of the common scaffold 130 can be carried out via an attack of intermediates of this type (e.g., 139) on Michael acceptors. Tosyl group deprotection of 130, followed by selenium anhydride oxidation and catalytic

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

• application scope, robustness, and selectivity [74]. Recently, an electrochemical NHPI/PINO-mediated benzylic iodination was achieved using lutidine or 2,6-di-tert-butylpyridine as bases with low nucleophilicity [89] (Scheme 10). When pyridine was used instead 2,6-disubstituted pyridines its N-benzylation by

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

• Konstantin Lebedinskiy,
• Volodymyr Lobaz and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

• activates isocyanates, affording reactions with alcohols. Since the hydroxy groups on the primary rim of CD express higher nucleophilicity than hydroxy groups on the secondary rim, this type of reaction is not observable with the permethylated primary ring. NMR studies of β-cyclodextrin dimers with

Simple synthesis of multi-halogenated alkenes from 2-bromo-2-chloro-1,1,1-trifluoroethane (halothane)

• Yukiko Karuo,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1567–1574, doi:10.3762/bjoc.18.167

• incompatibility with electron-withdrawing substituents can be attributed to lower nucleophilicity of the phenoxide ion and structural instability of the product, which could lead to unexpected reactions of 2h and 2i during the reaction or purification process. Phenols with allyl or vinyl substituents (3j and 3k

Ferrocenoyl-adenines: substituent effects on regioselective acylation

• Mateja Toma,
• Gabrijel Zubčić,
• Jasmina Lapić,
• Senka Djaković,
• Davor Šakić and
• Valerije Vrček

Beilstein J. Org. Chem. 2022, 18, 1270–1277, doi:10.3762/bjoc.18.133

• the acylation of purines from a regioselective to a regiospecific mode. Keywords: DFT; ferrocene; nucleophilicity; purine; steric effect; Introduction Nucleosides in which the sugar part is replaced with an organometallic moiety have attracted remarkable interest [1][2][3]. One important class are

• nucleophilicity [36] is an important factor in governing competition between the various nucleophilic centers in adenine. To estimate the relative inherent reactivity of different nucleophilic sites in the adenine anion, conceptual DFT tools were employed [37]. Specifically, frontier molecular orbital (FMO

• nucleophilicity (for details, see Computational part in Supporting Information File 1). In purines 2–5, the method for charge fitting suggests that the most positive part of the f– function is localized at the N6 atom, which means that this nitrogen is the most nucleophilic site in adenines (except 1 and 6). In

Dienophilic reactivity of 2-phosphaindolizines: a conceptual DFT investigation

• Nosheen Beig,
• Aarti Peswani and
• Raj Kumar Bansal

Beilstein J. Org. Chem. 2022, 18, 1217–1224, doi:10.3762/bjoc.18.127

• ) calculations have been used in recent years to predict the reactivity of organic molecules in reactions. We calculated global hardness (η), global softness (S), electronic chemical potential (μ), electrophilicity (ω), and nucleophilicity (N) indices of four classes of 2-phosphaindolizines, on the basis of

• ; Fukui function; global hardness; nucleophilicity index; 2-phosphaindolizines; Introduction In 1988, we developed a simple synthetic method for the synthesis of 1,3-azaphospholo[1,5-a]pyridine derivative (1, R1 = Me, R2 = PhCO) from the reaction of 2-ethyl-1-phenacylpyridinium bromide with PCl3 and Et3N

• calculate various reactivity descriptors, such as electrochemical potential, electrophilicity and nucleophilicity indices, global hardness, electronegativity, etc. The concept of hard–soft acid–base (HSAB) was used to explain the reactivity of the organic molecules towards electrophilic and nucleophilic

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

• Oleg A. Levitskiy,
• Olga I. Aglamazova,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121

• ). Notably, insertion of the second COOR group in the starting cyclopropane complex 4 completely suppresses this reaction channel: intramolecular cyclization of the anions formed in the reductive cleavage of the three-membered ring was not observed. This may be attributed to the decreased nucleophilicity as

• that follow-up functionalization of the anions formed after the ring opening with electrophiles (except H+) has low synthetic value due to multiple competing reaction channels observed in case of 3 and decreased nucleophilicity of 4. Consequently, it seems reasonable to focus on the one-pot

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• derivative 4a (1 equiv) and aliphatic amine 9a (2.5 equiv) in glacial acetic acid [42] resulted in the formation of product 10aa with a yield of only 36%. It is clear that compound 9a could be protonated in the acidic environment, decreasing its nucleophilicity and therefore, product 10aa was obtained in low

Electrochemical Friedel–Crafts-type amidomethylation of arenes by a novel electrochemical oxidation system using a quasi-divided cell and trialkylammonium tetrafluoroborate

• Hisanori Senboku,
• Mizuki Hayama and
• Hidetoshi Matsuno

Beilstein J. Org. Chem. 2022, 18, 1040–1046, doi:10.3762/bjoc.18.105

• -acyliminium ions, a proton source for which the conjugate base has no nucleophilicity would be necessary in the cathodic reduction. After several attempts, we finally reached HBF4·OEt2 as a proton source for cathodic reduction and the result is shown in entry 2 of Table 1. Strong increases of conversion of 1

• to HBF4·OEt, for which the conjugate base has no nucleophilicity, improved the yield of 2 and the conversion of 1. Incidentally, this reaction medium includes a base, iPr2NEt, that would accelerate the deprotonation step in the formation of N-acyliminium ions from DMA at the anode. TFA and HBF4·OEt2

Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics

• Durbis J. Castillo-Pazos,
• Juan D. Lasso and
• Chao-Jun Li

Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79

• salts 2 and an α-halopropiophenone. Unfortunately, initial attempts of a nucleophilic attack of sodium perfluorooctylsulfinate (2c) on α-bromopropiophenone (3) were unsuccessful to produce the desired product 1c due to the insufficient nucleophilicity of the sulfinate to substitute a bromide on a

• the molar ratio. Ranging from a 2.5:1 until a 10:1 molar ratio, yields increased significantly from 20% to 68%; however, a 5:1 ratio offered us a similar yield with a much shorter workup time when the reaction concentration was doubled. Knowing that nucleophilicity is a key factor in this reaction, we

Continuous flow synthesis of azobenzenes via Baeyer–Mills reaction

• Jan H. Griwatz,
• Anne Kunz and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2022, 18, 781–787, doi:10.3762/bjoc.18.78

• excellently for most of the electron-rich anilines due to their increased nucleophilicity. A comparison of ortho-, meta- and para-substituted derivatives revealed that for electron-rich anilines, the para-substituted ABs are formed in better yields as their ortho- and meta-analogues. For example, the

• . Low yields in case of electron-poor aniline derivatives can be explained by the reduced nucleophilicity. To exemplarily demonstrate the optimization for electron-poor derivatives, the synthesis of p-cyano-substituted AB 1o was repeated at higher temperatures. Thereby the yield of 1o could be increased

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• the interaction of the lowest unoccupied molecular orbital (LUMO) of the azomethine ylide 1 with the highest occupied molecular orbital (HOMO) of cyclopropenes 2. It follows that the greater the nucleophilicity of the cyclopropene substrate 2 is, the higher is its reactivity towards the 1,3-dipole 1

Tri(n-butyl)phosphine-promoted domino reaction for the efficient construction of spiro[cyclohexane-1,3'-indolines] and spiro[indoline-3,2'-furan-3',3''-indolines]

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 669–679, doi:10.3762/bjoc.18.68

• reagents to give versatile cyclic compounds with recovery of the tertiary phosphine [25][26][27][28][29][30][31][32][33][34]. The superior catalytic ability of tertiary phosphines was primarily attributed to their excellent nucleophilicity as a nucleophile trigger and decent cleaving ability as a leaving

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• catalyst and additive. The 1H NMR-spectroscopic analysis of the reaction showed that in both attempts no reaction occurred. It may be concluded that the nucleophilicity of the boronic ester is not sufficient, however, under the employed conditions, it can be hydrolyzed to the more reactive boronic acid

Regioselectivity of the S_EAr-based cyclizations and S_EAr-terminated annulations of 3,5-unsubstituted, 4-substituted indoles

• Jonali Das and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2022, 18, 293–302, doi:10.3762/bjoc.18.33

• highly nucleophilic indole C3 as the peri position, with the latter being often more nucleophilic than the former. Noteworthy is that the kinetic preference for ring-closure onto the C5 position may be a more dominating factor than the higher nucleophilicity of the C3 position (or vice versa). Due to

• substrates 20. Noteworthy is that substrates bearing an indolyl N–Ph or N–Boc moiety (instead of free indolyl N–H) failed to deliver the corresponding final cyclized products. The authors attributed this failure to the indole C3 position’s reduced nucleophilicity which thwarted the Michael addition step. In

• preference for cyclization onto the C5 position is more dominating than the higher nucleophilicity of the C3 position, making the CAr–C bond formation completely regioselective at the C5 position. Subsequently in 2017, Li and co-workers also applied the intramolecular Friedel–Crafts acylation strategy to get