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

• the perception that radicals cannot be selectively used took place with the introduction of tin hydrides in organic synthesis. Apart from the lower toxicity compared to organomercury reagents, the stability and longevity of tin-centered radicals allowed better propagation of radical chain reactions

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

• -emitting electrochemical cells LEECs were fabricated using DiKTa-OBuIm and DiKTa-DPA-OBuIm as emitters. The device stack was the following: ITO/PEDOT:PSS/emitter/Al (where ITO is indium tin oxide; PEDOT:PSS is poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)). The PEDOT:PSS and the emitter layers

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• ; for example, high triplet energy, good film-forming ability. OLED devices Finally, DICzTRZ and ICzTRZ-based OLEDs were fabricated using the following device structure: ITO (indium tin oxide) (50 nm)/PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) (35 nm)/PVK (poly(9-vinylcarbazole

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

• -catalyzed hydrolysis of protected racemic nucleosides to synthesize the enantiomerically pure oxathiolane nucleoside analogues 1 and 2 (Scheme 41). The protected racemic nucleoside derivatives 95 were synthesized by tin-mediated N-glycosylation of the corresponding acetate precursor 94 with silylated

Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation

• Azra Kocaarslan,
• Zafer Eroglu,
• Önder Metin and
• Yusuf Yagci

Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164

• when the components are light sensitive at short wavelength region and spatial control is required. Experimental Materials Red phosphorus (98.9%), tin (99.5%), and tin(IV) iodide (95%) were purchased from Alfa Aesar. Ethyl alcohol (absolute) was obtained from Sigma-Aldrich. Dimethyl sulfoxide (DMSO

• was synthesized according to a modified procedure [49]. To a Schlenk tube, 3-butyn-1-ol was dissolved in ε-caprolactone and heated to 110 °C under nitrogen. After the reaction mixture warmed up homogeneously, one drop of tin octoate was added to the reaction media and the solution was stirred for 3

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

• with cross-coupling using the same carbenoid and epoxide 5 (Scheme 5), where the presence of LTMP also proved necessary. A cinnamylamine 23 could be obtained in a tin-free process (Scheme 10), which utilises the increased acidity of a benzylic ether 22. In this case, the presence of LTMP was necessary

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• polymer 52 in good yields (Scheme 11). The other two polymers 54 and 56 were synthesized through Stille coupling reactions of 46 with 2,6-bis(trimethylstannyl)-4,8-bis(2-ethylhexyloxy)benzo[1,2-b:4,5-b’]dithiophene (53) and tin agent 55, respectively, as shown in the Scheme 12. These polymers 50, 52, 54

Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• composite with platinum nanoparticles stabilized with poly(acrylic acid) [113]. Such a catalytic system, obtained by layer-by-layer self-assembly with the addition of poly(diallyldimethylammonium chloride) on the indium tin oxide surface, provided hydrogen formation in photoelectrolytic cycles with a

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

• 35 which upon further reaction with silylated uracil in the presence of tin(IV) chloride via Vorbrüggen coupling afforded the protected double-headed nucleoside 36. The nucleoside 36 was finally deprotected in the presence of Pd(OH)2/C under hydrogen atmosphere to generate the double-headed

• ′-thymin-1-yl derivatives of 2′-deoxythymidine, i.e., compounds 59 and 60 starting from 5′-O-tritylthymidine (55). The tritylated thymidine 55 first was converted to the protected azide derivative 57 in two steps, followed by its reduction in the presence of tin(II) chloride, thiophenol and triethylamine

• , followed by reduction of the corresponding nucleoside with tin chloride produced nucleoside 62 which was treated as a key intermediate for the production of the double-headed nucleosides 63 and 64. Reaction of nucleoside 62 with 3-ethoxypropenoyl isocyanate or 3-methoxy-2-methylpropenoyl isocyanate in a

Prins cyclization-mediated stereoselective synthesis of tetrahydropyrans and dihydropyrans: an inspection of twenty years

• Asha Budakoti,
• Pradip Kumar Mondal,
• Prachi Verma and
• Jagadish Khamrai

Beilstein J. Org. Chem. 2021, 17, 932–963, doi:10.3762/bjoc.17.77

• DDQ and the subsequent abstraction of hydride from the benzylic or allylic position generated a charge-transfer complex 298. The complex 298 formed a tin-containing ate oxocarbenium ion complex 299 with SnBr4, and then rapid C–C bond formation took place to generate the cyclic intermediate 300. The

Beyond ribose and phosphate: Selected nucleic acid modifications for structure–function investigations and therapeutic applications

• Christopher Liczner,
• Kieran Duke,
• Gabrielle Juneau,
• Martin Egli and
• Christopher J. Wilds

Beilstein J. Org. Chem. 2021, 17, 908–931, doi:10.3762/bjoc.17.76

• by 5'-tritylation. In the case of guanosine, this strategy for 2'-OH methylation was unsuccessful, owing again to undesired methylation at the nucleobase. Instead, the 5'-O-monomethoxytrityl derivative of N2-isobutyrylguanosine was treated with diazomethane in dimethylformamide in the presence of tin

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• drawback because organomercury compounds are extremely toxic and environmentally persistent. Decomposition of trimethyl(trifluoromethyl)tin in the presence of sodium iodide: It is also possible to prepare difluorocyclopropanes from olefins and trifluoromethyl derivatives of tin such as trimethyl

• (trifluoromethyl)tin (48). There are two possible ways to obtain difluorocarbene from 48: thermal (at 140–150 °C, 20–44 h) [59] and iodide ion induced (at 85 °C, 16 h) (Scheme 19) [60]. The trapping with alkenes gave the expected cyclopropanes. The reaction of (СН3)3SnСF3 (48) with NaI (1 equiv) occurred in 1,2

• alcohols, ethers, esters, and amines (121, Scheme 53) [103]. They proposed that an initial tin–lithium exchange was followed by a β-elimination of LiF to form the intermediate cyclopropenes 119. The ring opening of the latter then generated the vinylcarbenes 120. The carbenes 120 could then insert into the

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7

• formal synthesis of inthomycin C ((−)-3). In 2018, Donohoe et al. demonstrated a tin-free, short and efficient total synthesis of inthomycin C ((−)-3) by comprising the three key steps of C−C bond-forming reactions: i) a vinylogous Mukaiyama aldol reaction, ii) an olefin cross-metathesis reaction, and

• Hale and Hatakeyama [57]. Recently, Burton’s group developed some efficient and tin-free total syntheses of all three inthomycins A–C ((+)-1, (+)-2, and (−)-3) using a Suzuki or Sonogashira cross-coupling of the (E)- or (Z)-alkenyl iodides 130 with the dienylboronic ester 128 as key step (Schemes 18–22

All-carbon [3 + 2] cycloaddition in natural product synthesis

• Zhuo Wang and
• Junyang Liu

Beilstein J. Org. Chem. 2020, 16, 3015–3031, doi:10.3762/bjoc.16.251

• .2.1] carbocyclic skeletons, which is applied to the synthesis of phyllocladanol (21) [68] (Scheme 12A). The IMCC precursor 147 was prepared from aldehyde 146 in nine steps. The IMCC precursor 147 underwent an intramolecular cross-cycloaddition catalyzed by tin tetrachloride to give tetracycle 149 in

Metal-free synthesis of biarenes via photoextrusion in di(tri)aryl phosphates

• Hisham Qrareya,
• Lorenzo Meazza,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 3008–3014, doi:10.3762/bjoc.16.250

• occurred as demonstrated by Havinga more than 70 years ago [69]. In alternative, the irradiation of monoaryl phosphates in the presence of a strong nucleophile (e.g., a tin anion) led to an ipso substitution reaction via an ArSRN1 process [70]. The situation dramatically changes when a further aryl group

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

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

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• brominated tin porphyrin (SnTBPP) as monomer (Scheme 47). The irradiation of this material in the presence of both sulfides and molecular oxygen furnished a variety of sulfoxides in 70–97% yields. The SnPor@PAF presented the same photocatalytic activity of its monomer (SnTBPP) with the advantage of its easy

Oligomeric ricinoleic acid preparation promoted by an efficient and recoverable Brønsted acidic ionic liquid

• Fei You,
• Xing He,
• Song Gao,
• Hong-Ru Li and
• Liang-Nian He

Beilstein J. Org. Chem. 2020, 16, 351–361, doi:10.3762/bjoc.16.34

• to industrial production [20][21][22][23][24][25]. Very recently, tin(II) 2-ethylhexanoate has been reported as an efficient catalyst for the synthesis of oligomeric ricinoleic acid [19]. Unfortunately, the separation of oligomeric ricinoleic acid and the recovery of the catalyst still encounters

Efficient method for propargylation of aldehydes promoted by allenylboron compounds under microwave irradiation

• Jucleiton J. R. Freitas,
• Queila P. S. B. Freitas,
• Silvia R. C. P. Andrade,
• Juliano C. R. Freitas,
• Roberta A. Oliveira and
• Paulo H. Menezes

Beilstein J. Org. Chem. 2020, 16, 168–174, doi:10.3762/bjoc.16.19

• organometallic species of Cd [16], Ga [17], In [18], Ti [19], Al [20] and Bi [21] were described. However, the majority of these methods involve reagents that are difficult to prepare and to handle due to the sensitivity to air and moisture. The use of less reactive species based on tin [22][23][24], silicon [25

• interesting to note that the nitro group remained intact under the reaction conditions. Usually, this group is sensitive to reduction when alternative methods involving zinc or tin are used [33]. In addition, aldehydes containing halogens also gave the corresponding products 2j–l in moderate yields. These

Extension of the 5-alkynyluridine side chain via C–C-bond formation in modified organometallic nucleosides using the Nicholas reaction

• Renata Kaczmarek,
• Dariusz Korczyński,
• James R. Green and
• Roman Dembinski

Beilstein J. Org. Chem. 2020, 16, 1–8, doi:10.3762/bjoc.16.1

• competing Lewis basic sites in 4 and 5. The use of tin(IV) chloride (stannic chloride) provided generally a slightly faster reaction but with slightly lower yields, except in the case of the 5/allyltrimethylsilane/7a combination (Table 1, entry 5). Reactions were more successful when the amount of

SnCl₄-catalyzed solvent-free acetolysis of 2,7-anhydrosialic acid derivatives

• Kesatebrhan Haile Asressu and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2019, 15, 2990–2999, doi:10.3762/bjoc.15.295

• in the presence of acetic anhydride. Among the various Lewis acids tested, the desired acetolysis products were obtained in moderate yields under tin(IV) chloride catalysis. Our methodology could be extended to regioselective protecting group installations and manipulations towards a number of

Indium-mediated C-allylation of melibiose

• Christian Denner,
• Manuel Gintner,
• Hanspeter Kählig and
• Walther Schmid

Beilstein J. Org. Chem. 2019, 15, 2458–2464, doi:10.3762/bjoc.15.238

• the elongated unit at the reducing end of the disaccharide. Keywords: carbohydrates; C–C bond formation; indium-mediated allylation; melibiose; ozonolysis; Introduction The tin and indium-mediated allylation (IMA) proved to be useful synthetic tools for the chain elongation of unprotected

• reported for the first time a tin-mediated allylation of unprotected carbohydrates followed by ozonolysis allowing for easy accessibility of the corresponding elongated sugars [2]. In the same year, Chan and Li introduced indium for the allylation of aldehydes and furthermore demonstrated the applicability

• concerning their effects on the conversion rate as well as the diastereoselectivity (Table 1). Concerning the metal species, it is known that indium provides several advantages compared to other allylation-mediating metals such as tin, as it allows the reaction to proceed under very mild conditions without

One-pot activation–alkynylation–cyclization synthesis of 1,5-diacyl-5-hydroxypyrazolines in a consecutive three-component fashion

• Christina Görgen,
• Katharina Boden,
• Guido J. Reiss,
• Walter Frank and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 1360–1370, doi:10.3762/bjoc.15.136

• (Figure 2) [26][27]. In addition, 1-acyl-5-hydroxypyrazolines are bidentate ligands for zinc complexes and by virtue of being ring tautomers of β-enolhydrazones they can also act as tridentate ligands for nickel [28] and tin [29][30] complexes. In contrast, dimethylzinc forms dimeric complexes where the 1

Azologization of serotonin 5-HT₃ receptor antagonists

• Karin Rustler,
• Galyna Maleeva,
• Piotr Bregestovski and
• Burkhard König

Beilstein J. Org. Chem. 2019, 15, 780–788, doi:10.3762/bjoc.15.74

• photochromic derivatives with varying electronic and thus photochromic properties. The respective arylamines 13a–c were converted into their corresponding hydrazines 14a–c via diazonium-salt formation using sodium nitrite and subsequent reduction using tin(II) chloride [70]. The following nucleophilic