Molecular diversity of the base-promoted reaction of phenacylmalononitriles with dialkyl but-2-ynedioates

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

Beilstein J. Org. Chem. 2022, 18, 991–998, doi:10.3762/bjoc.18.99

• multifunctionalized carboxamide-bridged dicyclopentenes in moderate to good yields and with high diastereoselectivity. Keywords: carboxamide; cycloaddition; cyclopentene; electron-deficient alkyne; phenacylmalononitrile; Introduction Phenacylmalononitrile is one of the privileged functionalized compounds [1][2][3

• -carboxamides with unprecedented rearrangement of the alkyl group [34] (reaction 4 in Scheme 1). Inspired by these novel reactions and in continuation of our aim to develop domino reactions of electron-deficient alkynes [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50], we have investigated the

• base to catalyze the C–C bond formation via a Michael addition of active methylene groups [31]. Therefore, in the presence of TBAB, the bromide assisted with the deprotonation of the phenacylmalononitrile to give a carbanion intermediate A. Secondly, the nucleophilic addition of carbanion A to electron

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• all the sulfur atoms of the DTT core and the electron-withdrawing [20] keto groups. The LUMO is presented strongly in the seven fused rings, but is poorly represented in the outer ethylhexylthiophenes, which are electron-rich and twisted out of plane. The LUMO is strongly localised at the electron

• -deficient keto groups. Interestingly, neither the HOMO, nor the LUMO, is present at the central sulfur atom of the DTT motif. Organic field-effect transistors To estimate the charge carrier mobility from the saturation regime of the current–voltage plot, bottom gate/bottom contact (BG/BC) OFETs [76][77

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90

• -phenylphosphonamidates 240a (R’ = OEt) and diaryl-N-phenylphosphinamides 240b–d (R’ = Ar), respectively, with methyl acrylate (241) via the rhodium-catalyzed oxidative coupling and subsequent intramolecular aza-Michael addition. Methyl acrylate (241) could be replaced by various electron-deficient olefins 244, including

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• ]. Considering the electrostatic potential surface (EPS) maps (see Figure 11b) of the pyrazine-containing polymers before and after B(C6F5)3 coordination, it is likely that B(C6F5)3 sacrificed the electron density of the polymer skeleton and turned it from an electron-rich to an electron-deficient species. This

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• temperature of the nanostructured particles (Figure 4B). The Claisen rearrangement of the electron-deficient aryl allyl ether 9 was chosen to compare the versatility and performance of inductive heating with conventional and microwave heating (Scheme 8A) [50]. The effectiveness of inductive heating is clearly

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

• the construction of diverse carbocyclic systems [17][18][19][20][21][22][23][24]. In these reactions, the tertiary phosphine firstly adds to electron-deficient alkenes, alkynes, and allenes to give active ionic intermediates. Then, the in situ-generated ionic intermediates further react with various

• respect, we have also developed several domino reactions by employing tertiary phosphine addition to electron-deficient alkynes as key protocol for the construction of diverse polycyclic spirooxindoles [53][54][55][56][57][58][59]. In continuation of our aim to explore elegant domino reactions for spiro

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• , fluorescence titration experiments were conducted. As presented in Figure 1c, the emission of TBTQ-CB6 was gradually reduced upon increasing the MV concentration, suggesting charge transfer from the electron-rich host to the electron-deficient guest. According to the fluorescence titration data, the

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• ]. Moreover, the number and nature of various side units on the emitter framework can also affect the properties of TADF compounds [3]. Among the electron-donating units, 9,10-dihydroacridine, carbazole or phenoxazine derivatives often are used as D units, while the π-electron-deficient nitrogen heterocycles

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• dichloromethane and tert-butyl hydroperoxide at 80 °C (Table 2, entry 12). Methylation of 1,4-naphthoquinone Another route to prepare menadione (10) involves the methylation of 1,4-naphthoquinone. Because of their electron-deficient character, quinones are highly reactive with nucleophilic radicals [75]. The most

• nucleophilic radical substitution to an electron-deficient aromatic compound, in the presence of silver(I) nitrate, ammonium persulfate, and heat, reaction conditions that are very similar to those of the Kochi–Anderson procedure. Under these conditions, the γ-picoline radical preferentially reacts with itself

Synthesis of 5-unsubstituted dihydropyrimidinone-4-carboxylates from deep eutectic mixtures

• Sangram Gore,
• Sundarababu Baskaran and
• Burkhard König

Beilstein J. Org. Chem. 2022, 18, 331–336, doi:10.3762/bjoc.18.37

• and the results are summarized in Table 1. The electron-rich (E)-ethyl 4-(4-methoxyphenyl)-2-oxobut-3-enoate (11) furnished the corresponding 5-unsubsituted DHPM derivative 12 on treatment with the ʟ-(+)-tartaric acid–DMU melt in very good yield (entry 3, Table 1). Moreover, electron-deficient β,γ

• derivatives in good yields under environmentally benign conditions. Electron-rich as well as electron-deficient, highly functionalized β,γ-unsaturated ketoesters proved to be excellent substrates in this cyclocondensation reaction. The carboxylic ester substitution at C4 position provides the option for

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• arylacetylenes in good yields (Scheme 4) [23]. The prepared Fe catalyst was found to be efficient and inexpensive, and could be recycled by filtration. This green strategy showed better yields in the presence of the inorganic base Cs2CO3 in DMF/H2O at 110 °C. Both electron-rich and electron-deficient aryl

• product yield was obtained. The ligands tested in the cross-coupling reaction were shown to have a dramatic impact on the yield of the final product. Electron-rich aryl iodides showed higher yields than electron-deficient ones. In addition, 2-thiophenyl iodide also showed good yields of the products with

Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography

• Kian Donnelly and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 232–239, doi:10.3762/bjoc.18.27

• aldehydes (Scheme 2) and subjected to the optimised flow conditions (Scheme 3). This resulted in full conversion of the substrate in all cases. Both thiophene and pyridine-containing substrates were well tolerated, with slightly higher yields observed in the case of the more electron-deficient CF3

• -substituted system (2a and 2c vs 2b and 2d). Both electron-rich and electron-deficient acyl hydrazones afforded high yields, with a slight decrease observed with the presence of the electron-withdrawing CF3 group in the case of the electron poor nitro-substituted substrate 2g. The reaction was also

Recent advances and perspectives in ruthenium-catalyzed cyanation reactions

• Thaipparambil Aneeja,
• Cheriya Mukkolakkal Abdulla Afsina,
• Padinjare Veetil Saranya and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 37–52, doi:10.3762/bjoc.18.4

• 6 h (Scheme 3). Differently substituted tertiary amines with electron-rich and electron-deficient substituents afforded the required products in good yields. This reaction was found to be suitable for N-aryl-substituted cyclic amines such as N-arylpiperidine, N-arylpyrrolidine, and N

• the oxidative cyanation of tertiary amines using Ru as the catalyst (Scheme 11) [35]. In this reaction, the comparatively safer acetone cyanohydrin was utilized as the cyanating agent. Better yields of products were obtained for both electron-rich and electron-deficient tertiary amines. Cyclic amines

• essential for promoting this reaction (Scheme 12). Both electron-rich and electron-deficient indoles afforded the desired products in good yields. The major advantages of this method include high regioselectivity, mild reaction conditions, and reusability of the catalyst. Two years later, in 2014, Ackermann

Bifunctional thiourea-catalyzed asymmetric [3 + 2] annulation reactions of 2-isothiocyanato-1-indanones with barbiturate-based olefins

• Jiang-Song Zhai and
• Da-Ming Du

Beilstein J. Org. Chem. 2022, 18, 25–36, doi:10.3762/bjoc.18.3

• under the action of catalyst C4. Simultaneously, deprotonated 1a attacks the double bond of 2a from the Si face via intermediate A, resulting in a Michael addition reaction. Then the electron-deficient isothiocyanate moiety is attacked by newly generated α-carbon center from barbiturate-based olefins 2a

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

• EWGs and EDGs on the phenyl ring were amenable to the reaction; however, the yield was dramatically reduced with electron-deficient N-substituents. Substitution of the alcohol partner was well-tolerated though sterically demanding functionality lowered its reactivity. On the basis of the experimental

• of the scope of the reaction, substrates bearing an electron-rich functionality were less reactive than substrates with electron-deficient groups. Isotopic labeling revealed the oxygen functionality installed came from the peroxide initiator rather than the water present, suggesting the water plays

• methodology was extended to the carbosilylation of olefins with carbon nucleophiles 108 including indoles, pyrroles, and 1,3-dicarbonyls. The scope of the reaction was broad and could tolerate a variety of functional groups; however, electron-deficient alkenes afforded the products in slightly diminished

Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group

• Chuanhua Qu,
• Run Huang,
• Yong Li,
• Tong Liu,
• Yuan Chen and
• Guiting Song

Beilstein J. Org. Chem. 2021, 17, 2822–2831, doi:10.3762/bjoc.17.193

• arylalkenes or alkynes provided an attractive option for the synthesis of vinyl sulfones [19][20][21][22][23] (Scheme 1B). However, in contrast to the reaction of TosMIC as tosyl source with various aryl olefins, reports relating to reactions of TosMIC with electron-deficient olefins such as p-QMs for the

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• Schiff bases 3bb–be with 40–89% yield for the isolated products after recrystallization from ethanol (Scheme 3). With some exceptions, electron-deficient or electron-rich substituted 2-aryl-6-aminoquinolines and aromatic aldehydes worked very well to furnish the Schiff bases 3. However, a poor yield (20

α-Ketol and α-iminol rearrangements in synthetic organic and biosynthetic reactions

• Scott Benz and
• Andrew S. Murkin

Beilstein J. Org. Chem. 2021, 17, 2570–2584, doi:10.3762/bjoc.17.172

• gel but not the electron-deficient p-trifluoromethylphenyl derivative. c) In the presence of silica gel or montmorillonite K 10, TBS-protected 101 is converted to 102 without any side products, but when sulfuric acid is used, only the deprotected product 103 is detected. d) Silica gel-catalyzed

Direct C(sp³)–H allylation of 2-alkylpyridines with Morita–Baylis–Hillman carbonates via a tandem nucleophilic substitution/aza-Cope rearrangement

• Siyu Wang,
• Lianyou Zheng,
• Shutao Wang,
• Shulin Ning,
• Zhuoqi Zhang and
• Jinbao Xiang

Beilstein J. Org. Chem. 2021, 17, 2505–2510, doi:10.3762/bjoc.17.167

• synergistic catalyzed allylic alkylation between electron-deficient 2-ethyl benzoxazoles and MBH carbonates by the combination of a Lewis base and a metal salt [24]. In their studies, although pyridine derivatives were also applicable in the reaction, the presence of a strong electron-withdrawing NO2 group

• was necessary to promote the reaction but only with low yield (30%) (Scheme 1c). Recently, electron-deficient 3,5-dimethyl-4-nitroisoxazole and 2-methyl-3-nitroindoles were also served as vinylogous pronucleophiles to proceed the asymmetric allylic alkylation with MBH carbonates [25][26]. Overall, the

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• ][19][20]. In this context, mainly the interaction between π-electron-deficient diimide groups and π-electron-rich pyrene moieties was applied resulting in a very strong and stable supramolecular bond [21][22]. The noncovalent interaction was found to be reversible and, therefore, enabled healing of

Efficient synthesis of polyfunctionalized carbazoles and pyrrolo[3,4-c]carbazoles via domino Diels–Alder reaction

• Ren-Jie Fang,
• Chen Yan,
• Jing Sun,
• Ying Han and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2021, 17, 2425–2432, doi:10.3762/bjoc.17.159

• , simple manufacture, high efficiency and atomic economy. The unusual feature of this reaction is the normal electron-demand Diels–Alder reaction between electron-deficient dienes such as (3-(indol-3-yl)maleimides and indole-chalcone to electron-deficient dienophilic chalcones. The potential applications

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

• the regioselective 2-functionalization of 1,3-dioxolane (13) with aryl chlorides 8. It was found that the electron-deficient aryl chlorides resulted in better yields within shorter reaction times over the electron-rich substrates. A possible catalytic cycle was shown to account for the reaction mode

• perchlorate ([Acr-Mes]+ClO4−) [64]. The reaction was conveniently achieved at room temperature under blue light irradiation. Moreover, as shown in Scheme 13, electron-deficient aryl bromides were efficient in forming the desired products 23 in optimal yields. In contrast, only trace amounts of cross-coupled

• the desired arylated products 17 (Scheme 14). Both electron-deficient and electron-rich aryl bromides proved viable substrates and afforded the products 10/17 in good yields. In addition to a variety of cyclic and acyclic ethers, amines, benzylic and alkane C(sp3)‒H bonds were also arylated under

Facile and innovative catalytic protocol for intramolecular Friedel–Crafts cyclization of Morita–Baylis–Hillman adducts: Synergistic combination of chiral (salen)chromium(III)/BF₃·OEt₂ catalysis

• Karthikeyan Soundararajan,
• Helen Ratna Monica Jeyarajan,
• Raju Subimol Kamarajapurathu and
• Karthik Krishna Kumar Ayyanoth

Beilstein J. Org. Chem. 2021, 17, 2186–2193, doi:10.3762/bjoc.17.140

• .17.140 Abstract The chiral (salen)Cr(III)/BF3·OEt2 catalytic combination was found to be an effective catalyst for intramolecular Friedel–Crafts cyclization of electron-deficient Morita–Baylis–Hillman adducts. In presence of mild reaction conditions the chiral (salen)Cr(III)/BF3·OEt2 complex affords 2

• Friedel–Crafts cyclization in electron-deficient Morita–Baylis–Hillman adducts. The present methodology is attractive because it directly utilizes MBH adducts over the possible reports on utilizing allylic-OH protected MBH adducts [12][13] to access indenes. The chiral Cr(III)(salen)/BF3·OEt2-catalyzed

• applications in inter/intraorganic molecular transformations, researchers are interested in creating novel, mild and efficient Friedel–Crafts methodologies. In spite of its worthwhile synthetic applications the Friedel–Crafts (FC) reaction faces a shortcoming and major challenge in operating with electron

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• synthesized the similar compound 40, using a catalytic Lewis acid Zn(NTf2)2 and stoichiometric Lewis base γ-picoline combination in n-butyronitrile as solvent (Scheme 7c) [61]. This electron-donating solvent and toluene in the former reaction acted as stabilizers to the electron-deficient silicon species in

• the similar mechanisms. First, the Brønsted or Lewis acid coordinates with silane 51 leading to a solvent-stabilized electron-deficient silane complex 57, where N-protected indole attacks in a Friedel–Crafts fashion to give the 3-silylindoles 60 along with molecular hydrogen (Scheme 7b and Scheme 7d

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• propargylic carbonates 113 with terminal alkynes 114. The scope of this reaction consisted of 12 examples that were synthesized in moderate to good yields (40–87%). The authors obtained the best yields by using electron-deficient aryl alkynes or secondary carbonates with electron-rich arene substituents (115a