(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

• complete conversion of the original olefins and the formation of allene 11. Thus, we have developed a method for the synthesis of the previously unknown allene 11. In addition, the possibility of using a mixture of olefins 3a,b made the allene 11 a more accessible synthon for studying its further

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

• C6 synthon, by a Hunsdiecker–Borodin bromodecarboxylation, adapting the recent micellar conditions developed by Rajanna for the synthesis of alkenyl halides starting from α,β-unsaturated acids [34]. However, purification and concentration of 1-bromopenta-1,3-diene proved to only promote its

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

• and carbohydrates to various carbocyclic scaffolds. This versatility arises from the possibility to chemoselectively cleave or reduce the sulfur-heterocycle to reveal a versatile C2-synthon. Keywords: 1,4-dithianes; 1,4-dithiins; 2,3-dihydro-1,4-dithiins; heterocycles; target synthesis; Introduction

• -fused dihydrodithiin ring is first hydrodesulfurized and then dehydroxylated in a stereospecific and stereoselective manner [62]. The dihydrodithiin building block 66 thus acts as a synthetic equivalent of an allyl alcohol anion and serves as a versatile synthon for de novo carbohydrate synthesis [63

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

• to trisubstituted (E)-alkenylboronates 55, acting as a 1,5-synthon, similar to Gutierrez‘s vinylcyclopropanes (Scheme 4) [66]. Based on mechanistic investigations, Koh proposed the catalytically active iron-boryl species 57 is generated through the ligand exchange of 56 with B2pin2 which can undergo

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

• . Therefore, there is great need to develop a more effective and rapid method for preparing diaryl methyl sulfones. p-Toluenesulfonylmethyl isocyanide (TosMIC), a versatile synthon in organic chemistry, has been widely used to synthesize a myriad of valuable chemicals due to its high reactivity shown by the

• important C1 synthon. Its special reactivity, such as the ability to react with electrophilic, nucleophilic, and radical reagents [25][26][27][28], determines that it can participate in many types of reactions such as multicomponent reactions [29][30][31][32], tandem reactions [33][34], and insertion

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• powerful nitrogen source for the synthesis of various N-heterocycles, such as isoquinolines, quinolines, pyridines, pyrroles, indoles, azoles, and azepines [40][41][42][43][44][45]. 1,3-Enyne, as a powerful Michael acceptor, is a wonderful synthon for the synthesis of N-heterocycles via tandem addition and

A novel methodology for the efficient synthesis of 3-monohalooxindoles by acidolysis of 3-phosphate-substituted oxindoles with haloid acids

• Li Liu,
• Yue Li,
• Tiao Huang,
• Dulin Kong and
• Mingshu Wu

Beilstein J. Org. Chem. 2021, 17, 2321–2328, doi:10.3762/bjoc.17.150

• . Thus, further work is needed to develop a novel strategy for an efficient synthesis of such a versatile synthon. On the other hand, diethyl (2-oxoindolin-3-yl) phosphates 2 were easily prepared by the base-catalyzed phospha-Brook rearrangement of isatins 1 with diethyl phosphite [28][29]. This compound

Total synthesis of ent-pavettamine

• Memory Zimuwandeyi,
• Manuel A. Fernandes,
• Amanda L. Rousseau and
• Moira L. Bode

Beilstein J. Org. Chem. 2021, 17, 1440–1446, doi:10.3762/bjoc.17.99

• retaining the stereogenic center. Divergence from the original route to pavettamine occurred after recovery of diol 5; and a different protecting group strategy was applied to arrive at synthon 4. The primary alcohol of the diol 5 was regioselectively protected using the trityl group under basic conditions

[2 + 1] Cycloaddition reactions of fullerene C₆₀ based on diazo compounds

• Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

• with a covalently attached fullerene molecule [86]. To this end, adduct 13 was obtained from 4-(tert-butoxycarbonyl)phenyldiazomethane and fullerene. Subsequent acid hydrolysis of the protective ester group quantitatively gave a derivative of carboxylic acid 14, a versatile synthon for the synthesis of

• methanofullerene-appended dicarboxylic acid 85 synthesized from 10 is a versatile synthon for conversion into numerous derivatives (Scheme 25). The reactivity of compound 85 was studied under DCC-promoted esterification conditions (see adducts 8 and 86) and amidation conditions (see adducts 21 and 22). Hummelen

CF₃-substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

• Anthony J. Fernandes,
• Armen Panossian,
• Bastien Michelet,
• Agnès Martin-Mingot,
• Frédéric R. Leroux and
• Sébastien Thibaudeau

Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32

• , which proved to be a valuable synthon for the introduction of the CF3 group into molecules [125]. Thus, 199 exhibits a high reactivity towards many functionalities, as depicted below (Scheme 49). Interestingly, 200 and 201 are sufficiently stable to be synthesized, presumably due to electron

Tuning the solid-state emission of liquid crystalline nitro-cyanostilbene by halogen bonding

• Subrata Nath,
• Alexander Kappelt,
• Matthias Spengler,
• Bibhisan Roy,
• Jens Voskuhl and
• Michael Giese

Beilstein J. Org. Chem. 2021, 17, 124–131, doi:10.3762/bjoc.17.13

• behaviour of halogen-bonded liquid crystals has been reported. In 2014, Tothadi and Desiraju reported on a new supramolecular synthon based on the non-covalent interaction between 1,4-dinitrobenzene and iodobenzene [13]. Their structural analysis of a series of ternary cocrystals revealed that the nitro

• group is a suitable halogen bond acceptor, which interacts with polarised iodobenzene components in three different geometries – symmetrical, unsymmetrical or sidewise. Many other crystal structures support these findings and suggest the suitability of this synthon for the construction of supramolecular

Design and synthesis of diazine-based panobinostat analogues for HDAC8 inhibition

• Sivaraman Balasubramaniam,
• Sajith Vijayan,
• Liam V. Goldman,
• Xavier A. May,
• Kyra Dodson,
• Sweta Adhikari,
• Fatima Rivas,
• Davita L. Watkins and
• Shana V. Stoddard

Beilstein J. Org. Chem. 2020, 16, 628–637, doi:10.3762/bjoc.16.59

• obstacle was overcome by using a modified Fieser work-up procedure to yield the aldehyde 6 in high yield, 78%. Then, aldehyde 6 was converted to the α,β-unsaturated trans-ester 7 through a Wittig reaction with the phosphorane synthon 8, which was derived from ethyl bromoacetate at 60 °C for 8 h in THF in

Regioselectively α- and β-alkynylated BODIPY dyes via gold(I)-catalyzed direct C–H functionalization and their photophysical properties

• Takahide Shimada,
• Shigeki Mori,
• Masatoshi Ishida and
• Hiroyuki Furuta

Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53

• BODIPY core has not yet been achieved. Inspired by the works of Waser and co-workers showing the gold(I)-catalyzed C–H electrophilic alkynylation of various heterocycles (e.g., pyrroles, indoles, etc.) with ethynylbenziodoxolone (EBX) as an activated ethynyl synthon [38][39][40][41][42], we investigated

Copper-catalyzed enantioselective conjugate addition of organometallic reagents to challenging Michael acceptors

• Delphine Pichon,
• Jennifer Morvan,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2020, 16, 212–232, doi:10.3762/bjoc.16.24

• product 59c, affording the key synthon 60 with a slight erosion of the optical purity (Scheme 22). α,β-Unsaturated N-acylpyrroles α,β-Unsaturated N-acylpyrroles were also investigated as Michael acceptors in enantioselective conjugate additions using organometallic reagents. In 2013, Endo and Shibata

Combination of multicomponent KA² and Pauson–Khand reactions: short synthesis of spirocyclic pyrrolocyclopentenones

• Riccardo Innocenti,
• Elena Lenci,
• Gloria Menchi and
• Andrea Trabocchi

Beilstein J. Org. Chem. 2020, 16, 200–211, doi:10.3762/bjoc.16.23

• cyclopentenone ring [37], as this heterocycle is a powerful synthon for the synthesis of a variety of bioactive target molecules, due to the broad diversity of chemical modifications available for the enone structural motif [38]. The most common approach to access such chemotype is the Pauson–Khand (PK) reaction

Application of chiral 2-isoxazoline for the synthesis of syn-1,3-diol analogs

• Juanjuan Feng,
• Tianyu Li,
• Jiaxin Zhang and
• Peng Jiao

Beilstein J. Org. Chem. 2019, 15, 1840–1847, doi:10.3762/bjoc.15.179

• oxidation conditions. Based on this assumption, the corresponding silyl nitronate from 3-nitropropanal or its acetal were not tried for cycloaddition. We then set to liberate the β-hydroxy ketone synthon by ring opening of the isoxazoline 3 (Scheme 3). Raney-Ni-catalyzed hydrogenolysis in the presence of

Vicinal difunctionalization of alkenes by four-component radical cascade reaction of xanthogenates, alkenes, CO, and sulfonyl oxime ethers

• Shuhei Sumino,
• Takahide Fukuyama,
• Mika Sasano,
• Ilhyong Ryu,
• Antoine Jacquet,
• Frédéric Robert and
• Yannick Landais

Beilstein J. Org. Chem. 2019, 15, 1822–1828, doi:10.3762/bjoc.15.176

• /acceptor type C1 synthons [6][7][8][9][10][11][12][13][14][15]. In this context, sulfonyl oxime ethers are powerful acceptors of type C1 synthon [8][16][17], which terminates the multicomponent reaction by a β-scission of RSO2 radicals [18][19][20]. Recently, one of us reported on a three-component radical

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

• Iwona E. Głowacka,
• Aleksandra Trocha,
• Andrzej E. Wróblewski and
• Dorota G. Piotrowska

Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168

• which is finally easily removed [11]. Among three-carbon chirons related to Garner’s aldehyde derivatives of N-(1-phenylethyl)aziridine-2-carboxylic acid 5–8 (Figure 2) play an important role in asymmetric synthesis as they function as a chiral synthon combined with a chiral auxiliary [(R)- or (S)-1

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• performed a Cu(OAc)2-Et3N-mediated coupling reaction of α-azido ketones 115 with pyridinium ylides 114 using oxygen as a green oxidant (Scheme 40). The oxo-functionality present in α-azido ketones increased its acidity thus making it a good organic synthon. Optimization of the reaction conditions revealed

Formation of an unexpected 3,3-diphenyl-3H-indazole through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate

• Andrew T. King,
• Hugh G. Hiscocks,
• Lidia Matesic,
• Mohan Bhadbhade,
• Roger Bishop and
• Alison T. Ung

Beilstein J. Org. Chem. 2019, 15, 1347–1354, doi:10.3762/bjoc.15.134

• sulfonyl fluorides in biological applications has been on the increase as evidenced by the number of recent publications [1][2][3]. One potential application of sulfonyl fluorides is as an 18F-radiolabelled synthon that can be conjugated to macromolecules and used to image cancer and other diseases in the

Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry

• Gábor Benkovics,
• Mihály Bálint,
• Éva Fenyvesi,
• Erzsébet Varga,
• Szabolcs Béni,
• Konstantina Yannakopoulou and
• Milo Malanga

Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66

• fact that in the large – kilogram – scale production of the key synthon 6-monotosyl-β-CD besides the desired product, over-tosylation occurs giving a mixture of regioisomers of ditosylated and tritosylated β-CDs. The ditosylated fraction represents a significant amount (10–20%) of the crude product

Polyaminoazide mixtures for the synthesis of pH-responsive calixarene nanosponges

• Antonella Di Vincenzo,
• Antonio Palumbo Piccionello,
• Alberto Spinella,
• Delia Chillura Martino,
• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2019, 15, 633–641, doi:10.3762/bjoc.15.59

• ) of polyaminoazide mixtures, which were in turn used for the preparation of CaNSs materials with pH-tunable properties, by reaction with the (5,11,17,23-tetra(tert-butyl))-(25,26,27,28-tetrakis(propargyloxy)calix[4]arene (Ca) under the CuAAC reaction conditions. In turn, the synthon Ca is obtained by

Gold-catalyzed ethylene cyclopropanation

• Silvia G. Rull,
• Andrea Olmos and
• Pedro J. Pérez

Beilstein J. Org. Chem. 2019, 15, 67–71, doi:10.3762/bjoc.15.7

• additives [11], alkylating reagent in the Friedel–Crafts synthesis of indanones [12] or as synthon toward the introduction of cyclopropyl moieties in compounds with medicinal or biological interest [13][14]. In view of the lack of examples of direct conversions of ethylene into cyclopropanecarboxylates, and

Revisiting ring-degenerate rearrangements of 1-substituted-4-imino-1,2,3-triazoles

• James T. Fletcher,
• Matthew D. Hanson,
• Joseph A. Christensen and
• Eric M. Villa

Beilstein J. Org. Chem. 2018, 14, 2098–2105, doi:10.3762/bjoc.14.184

• than originally reported are lacking. With an emerging interest in the 4-imino-1,2,3-triazole motif as coordination chemistry synthon, motivation for revisiting the ring degenerate rearrangements first described by L’abbe is twofold. A better understanding of parameters suppressing this rearrangement

• was undertaken. With a secondary aim of identifying improved reaction conditions for exploiting this rearrangement as an efficient synthetic tool for formyltriazole preparations, it was proposed that 1a might display significant advantages over previously utilized 1c [30][31][32][42] as a synthon for

• useful synthon for formyltriazole preparations, it was used to prepare analogs 1c (59% isolated yield) and 1d (64% isolated yield) by the kinetic assay conditions (see Supporting Information File 1). Optimizing of reaction yields and exploring of the scope of amine reagents tolerated by this

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• organic synthesis viewpoint, both CyNSs and CyCaNSs are “artificial” materials, in the sense that they derive from chemical manipulation of a natural occurring starting synthon, namely the cyclodextrin unit. We reasoned that it could be very interesting to explore the possibility of obtaining an entirely