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Search for "electrophilic" in Full Text gives 763 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Synthesis of medium and large phostams, phostones, and phostines

  • Jiaxi Xu

Beilstein J. Org. Chem. 2023, 19, 687–699, doi:10.3762/bjoc.19.50

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  • (biscollidine) hexafluorophosphates were efficient halogenium reagents in the electrophilic halocyclization. Hydrogen methyl hex-5-en-1-ylphosphonate (49) generated 2-methoxy-7-iodomethyl-1,2-oxaphosphepane 2-oxide (50a) in 65% yield in 62:38 diastereomeric ratio with iodo(biscollidine) hexafluorophosphate as
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Published 15 May 2023

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

Graphical Abstract
  •  4). Results and Discussion It is known that [e]-fused 1H-pyrrole-2,3-diones (FPDs) (Figure 2) are versatile synthetic platforms enabling the synthesis of numerous heterocyclic species [33][34][35][36]. They are polyelectrophilic compounds, bearing five electrophilic centers, whose reactivity
  • irradiation [49]. Secondly, the presence of a highly reactive thioester group C4=O [50] in FPDs 1 made us to expect the position C4 (Figure 2) to be the most reactive electrophilic center in these molecules, which would also contribute to the development of a new synthetic approach to PBTAs. We started our
  • proceeds through a different pathway from the one to pyrrolobenzothiazoles 3, 7, and 12. Biologically active PBTAs. Electrophilic centers in FPDs. Approaches to PBTAs via annulation of benzothiazoles. Approaches to PBTAs via annulation of o-aminothiophenols. Approach to PBTAs via radical substitution
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Published 11 May 2023

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

  • Péter Kisszékelyi and
  • Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

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  • recent realizations of this strategy focusing on lesser-studied trapping reactions and works after 2010. We also present here our attempts to broaden the scope of these enolate trapping reactions by using different types of electrophilic reagents. Review Conjugate additions with organozinc reagents
  • have shown that several electrophilic SCF3 reagents (e.g., 43) are suitable for enolate trapping (Scheme 10) [39]. This way, the strong electron-withdrawing SCF3 group can be efficiently introduced stereoselectively allowing access to structurally diverse compounds with altered pharmacochemical
  • was also possible. Among electrophilic reagents, unsaturated esters worked best. In collaboration with the Harutyunyan group, we have further explored the possibilities of chiral enolate trapping which were obtained by asymmetric conjugate addition of organometallic reagents. We intended to employ the
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Published 04 May 2023

Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes

  • Martina Mamone,
  • Giuseppe Gentile,
  • Jacopo Dosso,
  • Maurizio Prato and
  • Giacomo Filippini

Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42

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  • to photochemically generate electrophilic radicals that can drive the functionalization of suitable electron-rich substrates [23]. Exploiting this strategy, here we report a novel metal-free methodology for the direct homolytic aromatic substitution (HAS) reaction of indoles 1 with α-iodosulfones 2
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Published 27 Apr 2023

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

  • Austin Pounder,
  • Eric Neufeld,
  • Peter Myler and
  • William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

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  • –Cu species 60 which after electrophilic amination with the O-benzoylhydroxylamine 54 liberates the final aminoborylated product 55 and a benzoyl–Cu complex 61. To close the catalytic cycle a transmetalation of 61 with LiOt-Bu regenerates the active catalyst. In 2017, Xiao and Fu studied the Cu
  • suppress β-heteroatom elimination enabling sequential electrophilic trapping of the alkylzinc complex. Although this reaction would more closely fall under the definition of a telescoped reaction than a strict domino reaction, this methodology allowed for the synthesis of difunctionalized strained alkenes
  • authors were able to achieve enantioselectivities of up to 99%. Unfortunately, only two examples of electrophilic capturing were explored, using CD3CO2D to give deuterated products and I2. Most reports simply underwent protodemetalation upon quenching to afford the monosubstituted bicyclic alkene. The
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Published 24 Apr 2023

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

  • Louis Monsigny,
  • Floriane Doche and
  • Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

Graphical Abstract
  • involved in most cases an electrophilic SCF3 source (R1R2NSCF3). For these transformations, the following working hypothesis was generally suggested (Scheme 4). After coordination of the palladium catalyst to a directing group, the metallacycle A is formed. This latter undergoes an oxidative addition in
  • the presence of an electrophilic source or an oxidation/ligand exchange in the presence of a nucleophilic source (i.e., AgSCF3) and an oxidant (B in Scheme 4). Finally, after a reductive elimination step, the expected functionalized product 6 is obtained and the palladium catalyst is regenerated. In
  • 2014, Shen and Xu [117] developed a new methodology for the selective functionalization of 2-arylpyridine derivatives using an electrophilic SCF3 reagent, the Haas reagent I (Scheme 5) [118]. A broad range of 2-arylpyridine derivatives were trifluoromethylthiolated in good to high yields (18 examples
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Published 17 Apr 2023

Group 13 exchange and transborylation in catalysis

  • Dominic R. Willcox and
  • Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

Graphical Abstract
  • -hydroboration of the enone 29 with H-B-9-BBN to give an O-B-9-BBN enolate 30. Electrophilic cyanation of the enolate 30 with NCTS 31, and elimination gave the β-ketonitrile 33 and TsN(Ph)-9-B-BBN 34, which underwent B‒N/B‒H transborylation with HBpin to regenerate the catalyst and give TsN(Ph)-Bpin 35 (Scheme 8
  • (Scheme 16) [75]. The reaction was proposed to occur through activation of the alkyl fluoride 68 with H-B-9-BBN, followed by electrophilic substitution of the arene 69 to give a Wheland intermediate and a fluoroborohydride 70 (Scheme 16). Loss of H2 gave the arylated product 71, dihydrogen, and F-B-9-BBN
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Published 21 Mar 2023

Synthesis and reactivity of azole-based iodazinium salts

  • Thomas J. Kuczmera,
  • Annalena Dietz,
  • Andreas Boelke and
  • Boris J. Nachtsheim

Beilstein J. Org. Chem. 2023, 19, 317–324, doi:10.3762/bjoc.19.27

Graphical Abstract
  • highly versatile, and a wide range of applications is meanwhile established in organic synthesis [1][2][3][4][5]. They can be applied as mild oxidants [6][7][8], in phenol dearomatizations [9] or in α-oxygenation reactions [10]. In a complemental reactivity, diaryliodonium salts are potent electrophilic
  • , the reaction of 4aa in DCE at 50 °C gave the product 5aa in 23% yield (Table 1, entries 1 and 2). A larger amount of TfOH turned out to increase the solubility of the product and therefore impeded the purification process. However, an excess of acid is required for the electrophilic aromatic
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Published 16 Mar 2023

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

  • Cécile Alleman,
  • Charlène Gadais,
  • Laurent Legentil and
  • François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

Graphical Abstract
  • [4][5][6][7][8][9][10], the RCM reaction constitutes a powerful tool to construct rings of various sizes. In 2009, Vanderwal and Dowling extended this process to the use of allylsilane derivatives which can be further submitted to an electrophilic desilylation reaction [51][52][53][54] giving an
  • electrophilic desilylation agents which can be used, a large diversity of compounds can be accessible through this method [51][52]. Oxidation followed by desilylation with fluoride source produces the natural product poitediol (118) in overall good yield. 2 Nozaki–Hiyama–Kishi (NHK) cyclization The Nozaki
  • associated to ring closure. To reach this goal, they first dedicated efforts in optimal syntheses of an electrophilic enimide 151 [73] and its conjunctive reagent, the neopentyl iodide 153. Both fragments were then engaged in a two-fold neopentylic fragment coupling, giving a bicyclic intermediate which
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Published 03 Mar 2023

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

  • Bram Ryckaert,
  • Ellen Demeyere,
  • Frederick Degroote,
  • Hilde Janssens and
  • Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

Graphical Abstract
  • transformations of aryl substrates have also been reported for thiovinyl ethers, and also for dihydrodithiins (Scheme 5), although there are obvious limitations to this point of view. Classical electrophilic aromatic substitution procedures such as the Vilsmeier–Haack reaction or a simple nitration have been
  • reported for vinyl sulfides, including dihydrodithiin 13 (Scheme 5a) [36]. In fact, Parham has found that fully unsaturated dithiins can undergo this electrophilic formylation, but at the same time also undergo a ring contraction and an aromatizing desulfurization to yield thiophenes as the main formylated
  • products (viz 16, Scheme 5b) [37]. Electrophilic aromatic substitution under less forcing reaction conditions of the same substrate 15, using a room temperature nitration procedure, does yield the expected mononitrated dithiin 17 in good yield, without desulfurization [38]. 1,4-Dithiin-2-carbaldehyde (18
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Published 02 Feb 2023

Two-step continuous-flow synthesis of 6-membered cyclic iodonium salts via anodic oxidation

  • Julian Spils,
  • Thomas Wirth and
  • Boris J. Nachtsheim

Beilstein J. Org. Chem. 2023, 19, 27–32, doi:10.3762/bjoc.19.2

Graphical Abstract
  • -established reagents for synthetic chemists. They are portrayed as an alternative to otherwise hazardous transition metals. This is due to their great reactivity in electrophilic group transfers [1][2][3][4], photo- or organocatalysis [5][6][7][8][9][10][11][12][13][14][15], and their utility as building
  • blocks for the synthesis of natural products [16][17][18][19][20][21]. One subclass of HVIs is diaryliodonium salts (DIS), which have been used as versatile electrophilic arylation reagents in metal-catalyzed and metal-free reactions [22][23]. The corresponding cyclic diaryliodonium salts (CDIS) have
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Published 03 Jan 2023

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

Graphical Abstract
  • play an important role in redox-neutral asymmetric organocatalysis by forming nucleophilic enamine intermediates or electrophilic iminium cations. The same principles are used in oxidative transformations, where an amine can play the role of chirality source and the activator of substrate for oxidation
  • (Scheme 2). In the enamine type of catalysis (Scheme 2A) the key enamine intermediate can undergo one-electron oxidation (route 1), electrophilic radical attack (route 2), or electrophile attack (route 3). The one-electron oxidation leads to the electrophilic cation radical which can further undergo
  • addition to the electron-rich C=C bond [58] or proton loss followed by β-functionalization [59][60][61]. The iminium cation catalysis is used in the activation of electrophilic properties of enones for the nucleophilic epoxidation by hydroperoxides (Scheme 2B). N-Heterocyclic carbene (NHC) organocatalysis
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Published 09 Dec 2022

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

  • Keith P. Reber and
  • Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

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  • -stereogenic center, which bears a methyl group, the electrophilic site (the iminium ion), and two possible nucleophilic sites (a prenyl group and a trisubstituted alkene within a cyclohexene ring). In conformer 12a, the prenyl group occupies a pseudo-axial position, the methyl group occupies a pseudo
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Published 01 Dec 2022

Functionalization of imidazole N-oxide: a recent discovery in organic transformations

  • Koustav Singha,
  • Imran Habib and
  • Mossaraf Hossain

Beilstein J. Org. Chem. 2022, 18, 1575–1588, doi:10.3762/bjoc.18.168

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  • reaction. However, in this reaction process, 2.0 equiv of CH-acids were needed against arylglyoxals since the electrophilic character of glyoxals is higher than that of aldehydes, generating less stable enones while reacting with CH-acids. First, 1.0 equiv CH-acid was reacted with 1.0 equiv arylglyoxal to
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Published 22 Nov 2022

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

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  • involved a highly reactive difluoroethylene intermediate, which was produced by the reaction between halothane and KOH. Keywords: aryl 1-monofluorovinyl ether; electrophilic 1,1-difluoroethene; halothane; multi-halogenated alkene; phenol; Introduction 2-Bromo-2-chloro-1,1,1-trifluoroethane (halothane
  • , respectively), which are susceptible to basic conditions, were tolerated in the reaction, but ortho substituents hindered the reaction to some extent (Table 2, entries 9 and 10). 2-Hydroxychalcone (3l), which has an electrophilic enone structure, was also tolerated. The Michael addition product was not
  • mechanism shown in Scheme 2 [15][26]. In the reaction medium, 3 is deprotonated by KOH to generate phenoxide ion 4, which acts as a base and as a nucleophile. Removal of an acidic hydrogen from halothane provides 5, which is a key intermediate in the reaction. Intermediate 5 is sufficiently electrophilic to
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Published 21 Nov 2022

A facile approach to spiro[dihydrofuran-2,3'-oxindoles] via formal [4 + 1] annulation reaction of fused 1H-pyrrole-2,3-diones with diazooxindoles

  • Pavel A. Topanov,
  • Anna A. Maslivets,
  • Maksim V. Dmitriev,
  • Irina V. Mashevskaya,
  • Yurii V. Shklyaev and
  • Andrey N. Maslivets

Beilstein J. Org. Chem. 2022, 18, 1532–1538, doi:10.3762/bjoc.18.162

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  • formal [4 + 1] cycloaddition (Scheme 1). Results and Discussion FPDs are highly reactive compounds [25][26] containing an highly electrophilic enone fragment which facilitates the course of cycloaddition and nucleophilic addition reactions. In recent years, some types of cycloaddition reactions were
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Published 10 Nov 2022

Design, synthesis, and evaluation of chiral thiophosphorus acids as organocatalysts

  • Karen R. Winters and
  • Jean-Luc Montchamp

Beilstein J. Org. Chem. 2022, 18, 1471–1478, doi:10.3762/bjoc.18.154

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  • synthesized from 2-aminobiphenyl according to the literature [47]. Subsequent reaction with phosphorus trichloride and electrophilic aromatic substitution gave a chlorophosphine intermediate, which was directly reacted with (S)-1-phenylethylamine, then hydrogen peroxide. Phosphonamide diastereoisomers 17 were
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Published 17 Oct 2022

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

  • Artem N. Semakin,
  • Ivan S. Golovanov,
  • Yulia V. Nelyubina and
  • Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

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  • functionalized through the addition of electrophilic reagents, various functional arms can be attached. Moreover, N-TAAD derivatives were expected to be less prone to cage-opening reaction compared to 3O-TAADs. Here, we wish to report the synthesis of TAADs decorated with N-amino(amido) groups (3N-TAADs) by
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Published 11 Oct 2022
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  • due to the strong electron-withdrawing effect of bromine, enhancing the electrophilic property of bromo-substituted salicylaldehyde. Because of the poor solubility in the eluent, the yield of dichloro-containing 1c (88%) was lower than 1a after isolating by column chromatography. This was also found
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Published 10 Oct 2022

Synthesis of C6-modified mannose 1-phosphates and evaluation of derived sugar nucleotides against GDP-mannose dehydrogenase

  • Sanaz Ahmadipour,
  • Alice J. C. Wahart,
  • Jonathan P. Dolan,
  • Laura Beswick,
  • Chris S. Hawes,
  • Robert A. Field and
  • Gavin J. Miller

Beilstein J. Org. Chem. 2022, 18, 1379–1384, doi:10.3762/bjoc.18.142

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  • accepted. Evaluation of GDP 6-chloro-6-deoxy-ᴅ-mannose suggests that the ligand can bind to GMD, but that targeting inhibitive S-alkylation of an sp3-hybridised C6 electrophilic probe is ineffective here. a) Proposed oxidative pathway for provision of GDP-ManA 5 from GDP-Man 1, C6 stereochemistry of 3 is
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Published 30 Sep 2022

Cytochrome P450 monooxygenase-mediated tailoring of triterpenoids and steroids in plants

  • Karan Malhotra and
  • Jakob Franke

Beilstein J. Org. Chem. 2022, 18, 1289–1310, doi:10.3762/bjoc.18.135

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  • compound 0. This nucleophilic and basic intermediate is prone to dehydration (step 6), leading to the strongly electrophilic and oxidising key intermediate G, which is commonly known as compound I (cpd I). Although there has been a lot of debate regarding the exact structure and electronic properties of
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Published 21 Sep 2022

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

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  • electrophilic substrates (Figure 2). The HOMO orbital is distributed over the purine ring with the largest amplitude on the N7 atom, which designates this position as the most nucleophilic in 1. The second most populated site is the N6 atom, which appears as more nucleophilic than N9 atom. To facilitate a
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Published 19 Sep 2022

Modular synthesis of 2-furyl carbinols from 3-benzyldimethylsilylfurfural platforms relying on oxygen-assisted C–Si bond functionalization

  • Sebastien Curpanen,
  • Per Reichert,
  • Gabriele Lupidi,
  • Giovanni Poli,
  • Julie Oble and
  • Alejandro Perez-Luna

Beilstein J. Org. Chem. 2022, 18, 1256–1263, doi:10.3762/bjoc.18.131

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  • on the SiMe(OSiMe3)2 unit, which were readily converted through Pd- or Cu-catalyzed electrophilic substitution reactions into an array of furfurals decorated at C3 with carbon- or heteroatom-containing substituents (Scheme 1). Conversely, all of our subsequent efforts to achieve cross-coupling
  • activation [19]. Thereby, C3-triorganosilyl-substituted furfurals could be suitable platforms to develop a two-step modular approach to 3-substituted 2-furyl carbinols, entailing nucleophilic addition to the aldehyde function and oxygen-assisted electrophilic substitution of the C–Si bond (Scheme 1). Results
  • ). With the 3-silylated 2-furyl carbinol substrates at hand, we then considered C–Si bond activation strategies relying on the assistance of the oxygen atom to promote electrophilic substitution reactions with carbon electrophiles. C3–Si bond functionalization through intramolecular activation by
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Published 16 Sep 2022

Vicinal ketoesters – key intermediates in the total synthesis of natural products

  • Marc Paul Beller and
  • Ulrich Koert

Beilstein J. Org. Chem. 2022, 18, 1236–1248, doi:10.3762/bjoc.18.129

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  • intermediates in the total synthesis of natural products utilizing their electrophilic keto group as reactive site. Suitable key reactions are, e.g., aldol additions, carbonyl ene reactions, Mannich reactions, and additions of organometallic reagents. The vicinal arrangement of carbonyl groups allows the
  • bearing an electrophilic keto group as reactive site. The vicinal arrangement of carbonyl groups allows the stabilization of reactive conformations by chelation or dipole control. Suitable key reactions are e.g., aldol additions, carbonyl ene reactions, Mannich reactions, and additions of organometallic
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Published 15 Sep 2022

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

Graphical Abstract
  • which their observed relative dienophilic reactivities could be rationalized. Besides, the Fukui functions of the carbon/nitrogen and phosphorus atoms of the >C=P– and –N=P– functionalities were also computed which revealed their hard electrophilic character and accorded well with the dienophilic
  • 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
  • reagents [19]. Thus a quantitative descriptor, the Fukui function was defined as for nucleophilic attack and for electrophilic attack, where ρN+1(r), ρN(r), and ρN−1(r) are the electron densities at a point r in the system with N+1, N, and N−1 electrons, respectively, all with the ground-state geometry
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Published 13 Sep 2022
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