Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• the non-doped device, at 2.0% demonstrated 100% exciton utilization efficiency in the device and efficient energy transfer from the host to the guest cyanine emitter. Deep blue emission in LEECs is challenging. We also reported a blue-emitting LEEC employing a cationic sulfone-based donor–acceptor

A one-pot electrochemical synthesis of 2-aminothiazoles from active methylene ketones and thioureas mediated by NH₄I

• Shang-Feng Yang,
• Pei Li,
• Zi-Lin Fang,
• Sen Liang,
• Hong-Yu Tian,
• Bao-Guo Sun,
• Kun Xu and
• Cheng-Chu Zeng

Beilstein J. Org. Chem. 2022, 18, 1249–1255, doi:10.3762/bjoc.18.130

• protocol proceeds in an undivided cell equipped with graphite plate electrodes under constant current conditions. Various active methylene ketones, including β-keto ester, β-keto amide, β-keto nitrile, β-keto sulfone and 1,3-diketones, can be converted to the corresponding 2-aminothiazoles. Mechanistically

• 3v in 23% yield. In addition to β-keto esters, other active methylene derivatives, including β-ketoamide, β-keto nitrile and β-keto sulfone were also suitable coupling partners with relatively lower yields (3w–y) and most of the starting materials were recovered. The method could also be applied to

• performed in an undivided cell with NH4I as the mediator and cheap graphite plate as the working electrode. Various active methylene ketones, including β-keto ester, β-keto amide, β-keto nitrile, β-keto sulfone and 1,3-diones proved to be compatible with the protocol. Since external oxidants and

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

• ethyl and butyl acrylates, but-3-en-2-one, N,N-dimethylacrylamide, acrylonitrile, and phenyl vinyl sulfone. In addition, ethyl 1-arylvinyl-N-phenylphosphonamidates 246 were able to react with methyl acrylate (241), affording methyl 2-(3-aryl-2-ethoxy-2-oxo-1-phenyl-1,5-dihydro-1,2-azaphosphol-5-yl

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

• generated in situ from propiophenone, and second, the deprotection of propiophenone α-thioesters in the presence of perfluoroalkyliodides and subsequent oxidation of the formed perfluorothioether into the sulfone. However, none of these proposed pathways gave yields high enough for the reaction to be

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

• such as triazine, diazines or aromatics containing cyano and sulfone groups are popular acceptor units for the construction of highly efficient TADF emitters [8][9][10][11]. Pyrimidine (1,3-diazine) owing to its aromaticity, significant π-deficiency, strong electron affinity, high luminous efficiency

DABCO-promoted photocatalytic C–H functionalization of aldehydes

• Bruno Maia da Silva Santos,
• Mariana dos Santos Dupim,
• Cauê Paula de Souza,
• Thiago Messias Cardozo and
• Fernanda Gadini Finelli

Beilstein J. Org. Chem. 2021, 17, 2959–2967, doi:10.3762/bjoc.17.205

• was the study of the aldehyde scope, using 4-bromophenyl methyl sulfone as a coupling partner. We were delighted to see that both aliphatic and aromatic aldehydes could be arylated using this protocol with good to excellent yields (13–16, 69–89%), although 4-anisaldehyde led to a diminished yield when

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

• diarylmethyl sulfone 3e. The chemistry of TosMIC in the reactions with olefins. ZnI2-catalyzed C–S-bond cleavage of TosMIC for the synthesis of diarylmethyl sulfones 3a–m. Reaction conditions unless otherwise specified: 1 (0.2 mmol), 2a (0.4 mmol), ZnI2 (0.04 mmol), Cs2CO3 (0.4 mmol), THF (1.0 mL), MW 90 °C

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

• , agrochemical, and organic synthetic chemistry. For example, 5-selenyl- and 5-sulfenyl-appended nicotinates 18c and 19c could be oxidized by mCPBA to the corresponding selenoxide, sulfoxide, and sulfone derivatives 22, 24, and 25, respectively. In addition, 5‑selenyl-substituted nicotinate 18c could be

Allylic alcohols and amines by carbenoid eliminative cross-coupling using epoxides or aziridines

• Matthew J. Fleming and
• David M. Hodgson

Beilstein J. Org. Chem. 2021, 17, 2385–2389, doi:10.3762/bjoc.17.155

• ). Access to allylic alcohol 8 was also achievable (55%, E/Z = 56:44) in a tin-free process using a sulfonyl leaving group, via α-lithiation of sulfone 15 [18] and in the presence of LTMP (Scheme 7). γ-Hydroxysulfone 16 was formed competitively (44%, dr = 50:50), by direct addition of the lithiated sulfone

• epoxide 5. Synthesis of vinylsilane 14. Allylic alcohol 8 from epoxide 5 and sulfone 15. Allylic amines from aziridine 17. Cyclopropylidene synthesis from aziridine 20. Cinnamylamine 23 synthesis from aziridine 17. Cinnamylamine 23 synthesis from isopropyl or neopentyl benzylic ethers 26 and 27

Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions

• Susanne M. Fischer,
• Simon Renner,
• A. Daniel Boese and
• Christian Slugovc

Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117

• triarylphosphines TPP, MMTPP and TMTPP as catalysts for the oxa-Michael reaction three varyingly strong Michael acceptors, namely acrylonitrile (1), acrylamide (2) and divinyl sulfone (3) were reacted with four different alcohols of similar molecular mass but different acidity (Figure 1). The stoichiometry of

• , the difunctional divinyl sulfone was tested as the strongest Michael acceptor (E = −18.36, for phenyl vinyl sulfone [19]) under investigation. In distinction from the experiments described above, three equivalents of the alcohol were used. In general, the different catalysts perform very similar in

• this reaction giving high double-bond conversions of about 80% after already 1 h [26]. A mixture of mono- (3monoa–d) and di-adducts (3dia–d) are observed and only in case of 2-propanol also divinyl sulfone is still present. With 2-propanol a slight but significant influence of the catalyst choice on

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• of N-heterocyclic compounds. In 2017, Wu and colleagues [58] uncovered the use of the bis(sulfur dioxide) adduct of DABCO, 1,4-diazabicyclo[2.2.2]octane·(SO2)2, as sulfone source in the EDA complex formation by 4-methyl-1-(p-tolyl)pentan-1-one O-(2,4-dinitrophenyl)oxime (11) towards the

• trifluoromethyl alkynylation product 84 with alkynyl sulfone 83, alkene 81, and Togni reagent 82 as substrates catalyzed by 2,4,6-trimethylpyridine (TMP). The EDA complex formed by electron donor TMP and electron acceptor Togni reagent 82 facilitated electron transfer, yielding trifluoromethyl radical to initiate

The synthesis of chiral β-naphthyl-β-sulfanyl ketones via enantioselective sulfa-Michael reaction in the presence of a bifunctional cinchona/sulfonamide organocatalyst

• Deniz Tözendemir and
• Cihangir Tanyeli

Beilstein J. Org. Chem. 2021, 17, 494–503, doi:10.3762/bjoc.17.43

• , which have potent activity against breast cancer. The easy access to the corresponding sulfones presents a versatile route for the implementation of a new biologically active moiety, the sulfone, to the β-naphthyl-β-sulfanyl ketones. The enantioenriched products of both classes can be evaluated as

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

Isolation and structure determination of a tetrameric sulfonyl dilithio methandiide in solution based on crystal structure analysis and ⁶Li/¹³C NMR spectroscopic data

• Jürgen Vollhardt,
• Hans Jörg Lindner and
• Hans-Joachim Gais

Beilstein J. Org. Chem. 2020, 16, 2057–2063, doi:10.3762/bjoc.16.172

• substructure of which could be disclosed [15]. We describe in this paper the isolation of a tetramer of 2a and the determination of its structure in solution based on crystal structure analysis and previously described NMR spectroscopic data. Results and Discussion Crystal structure Treatment of sulfone 4 in a

• (2a)4·(THF)6 are in the range of those found in the hexamer (2a)6·Li2O·(THF)6 and functionalized dilithio sulfonyl methandiides [40][43]. Solution structure The synthesis of 2a from sulfone 6Li and 13C-labelled 4 with Li2O-free n-BuLi had yielded the methandiide, being readily soluble in THF. 13C and

Syntheses of spliceostatins and thailanstatins: a review

• William A. Donaldson

Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166

• oxidation stereoselectively generated the spirocyclic epoxide 76. A second-protecting group shuffle afforded the primary alcohol 77. A Mitsunobu substitution of 77 with 2-mercaptobenzothiazole, followed by an oxidation with a large excess of mCPBA afforded the sulfone 78. While not producing the identical

• afforded the fragment 125. The cross-metathesis of 125 with an excess of methacrolein in the presence of the Ru catalyst 122 gave the aldehyde 126. This coupling is analogous to Koide’s cross-metathesis of 121 (cf. Scheme 20). A modified Julia olefination of 126 with the anion generated from the sulfone 78

• , followed by the cleavage of the 4’-TBS protecting group gave 127 in an acceptable yield (52%). A protecting-group adjustment finalized the synthesis of 124. Notably, these authors found that switching the sulfone and aldehyde functionalities, i.e., an olefination of the aldehyde generated by the oxidation

Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

• Marek Baráth,
• Jana Jakubčinová,
• Zuzana Konyariková,
• Stanislav Kozmon,
• Katarína Mikušová and
• Maroš Bella

Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152

• investigations on their more stable analogs resulted in the synthesis of stable 1-O-phoshono-β-ᴅ-psicofuranosyl sulfone, which was prepared by a simultaneous phosphorylation and oxidation of ethyl 2-thio-β-ᴅ-psicofuranoside with dibenzyl N,N-dimethylphosphoramidite catalyzed by 1H-tetrazole and followed by

• thiol from exo-face of the bicyclic skeleton. Subsequent simultaneous phosphorylation and oxidation of ethyl 2-thio-ᴅ-tagatofuranoside 13 under identical conditions as used for the fructofuranose pathway provided 1-O-dibenzyloxyphosphoryl-ᴅ-tagatofuranosyl sulfone 14 (Scheme 3). Removal of the pivaloyl

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• testing a variety of reaction conditions. More complex biorelevant examples such as isatin derivatives were also suitable substrates, affording the corresponding spirocyclic derivatives, albeit in low yields (Scheme 21) [59]. Unfortunately, thioether and sulfone-based linkers were unsuitable in this

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• (Figure 11) [129]. Four conjugated polymers containing dibenzothiophene sulfone (FSO) monomers, linked by either biphenyl (FSO-BP), fluorene (FSO-F), 2,8-dibenzothiophene (FSO-FSz), or 3,7-dibenzothiophene (FSO-FS) monomers were synthesised and applied in the photocatalytic hydrogen evolution reaction

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

Asymmetric synthesis of CF₂-functionalized aziridines by combined strong Brønsted acid catalysis

• Xing-Fa Tan,
• Fa-Guang Zhang and
• Jun-An Ma

Beilstein J. Org. Chem. 2020, 16, 638–644, doi:10.3762/bjoc.16.60

• Tianjin University, Fuzhou 350207, China 10.3762/bjoc.16.60 Abstract A diastereo- and enantioselective approach to access chiral CF2-functionalized aziridines from difluorodiazoethyl phenyl sulfone (PhSO2CF2CHN2) and in situ-formed aldimines is described. This multicomponent reaction is enabled by a

• phosphoric acid (Scheme 1a) [26]. In comparison, there is a significant dearth of available synthetic approaches to CF2-functionalized aziridines, particularly in a stereocontrolled manner. Indeed, a handful of reported methods document the employment of difluoromethylimines, difluoromethyl phenyl sulfone

• phenyl sulfone under mild conditions by a combined strong Brønsted acid system consisting of chiral disulfonimide and 2-carboxyphenylboronic acid. The optical purity of the obtained CF2-substituted aziridines could be further improved by a practical dissolution–filtration procedure. Substrate expansion

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• isolated in moderate to good yields. Using the more reactive allyl sulfone, a panel of symmetrical diaryliodonium salts was reacted, giving the products in good yields. The authors conducted some mechanistic studies and suggested a plausible catalytic cycle involving [Cu(I)]/[Cu(I)]*/[Cu(II)] species. The

Copper-promoted/copper-catalyzed trifluoromethylselenolation reactions

• Clément Ghiazza and
• Anis Tlili

Beilstein J. Org. Chem. 2020, 16, 305–316, doi:10.3762/bjoc.16.30

• arylcopper(I) species was the key intermediate. Terminal alkynes were also investigated under similar reaction conditions (Scheme 13) [37]. Aromatic and π-activated aliphatic substrates led to the desired products in moderate to very good yields. Moreover, vinyl sulfone derivatives were formed when the

Iodine-mediated hydration of alkynes on keto-functionalized scaffolds: mechanistic insight and the regiospecific hydration of internal alkynes

• Zachary Lee,
• Brandon R. Jones,
• Nyochembeng Nkengbeza,
• Michael Phillips,
• Kayla Valentine,
• Alexis Stewart,
• Brandon Sellers,
• Nicholas Shuber and
• Karelle S. Aiken

Beilstein J. Org. Chem. 2019, 15, 2747–2752, doi:10.3762/bjoc.15.265

• were used to probe the existence of an α-iodo intermediate 9, and methodology work was used to investigate the outcome of the reaction using alkyl-capped, asymmetric, internal alkynes 11. The NMR investigations utilized different electrophilic iodine sources and the β-keto sulfone 8, which allowed for

• intermediate 9, we turned our attention to investigating the reaction of internal alkynes 11 to examine the regioselectivity of the hydration process. Ester, sulfone, and phosphonate substrates were employed and, in all cases, the internal alkyne unit was capped by an ethyl group (Scheme 2). In general

• recovered. In contrast, the phosphonate 11d and the sulfone 11e smoothly converted to 15d and 15e in yields of 68% and 71%, respectively. The hydration of the phosphonate required 22 h, while the reaction of the sulfone was complete in 3.5 h. Overall, successful outcomes were obtained for the phosphonate

Fluorine-containing substituents: metabolism of the α,α-difluoroethyl thioether motif

• Andrea Rodil,
• Alexandra M. Z. Slawin,
• Nawaf Al-Maharik,
• Ren Tomita and
• David O’Hagan

Beilstein J. Org. Chem. 2019, 15, 1441–1447, doi:10.3762/bjoc.15.144

• significantly more slowly to the sulfone. When the substrate was (p-OMe)PhSCF2CH3, then the resultant (demethylated) phenol sulfoxide had an enantiomeric excess of 60%, and when the substrate was the β-substituted-SCF2CH3 naphthalene, then the enantiomeric excess of the resultant sulfoxide was 54%. There was no

• 19F NMR spectrum consistent with non-equivalence of the fluorines, immediately indicative of sulfoxide formation. Isolation and subsequent 1H and 19F NMR analyses as well as high-resolution mass spectrometry secured the identity of these metabolites as sulfoxides 6 and 7 and sulfone 8. The structure

• . Sulfone 8 was a relatively minor metabolite, at only 10% of sulfoxide 6. A chiral HPLC (IC column, solvent: 5% isopropanol in hexane; 1 mL/min) enantiomeric assay was conducted for sulfoxide 6 and the outcome compared with a racemic sample of 6, prepared by chemical oxidation of thioether 4 [22]. Although