Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• /Fc+) [49]. By directly connecting the NI and PTZ unit through a C–N single bond, the π-conjugation plane of the NI and PTZ units adopts a perpendicular geometry which is beneficial for SOCT-ICS (Scheme 1). Previously we observed TADF with an analogue of NI-PTZ-C5 (the difference of the molecular

• structures is the alkyl chain, we called that analogue NI-PTZ-N here) [39]. In order to study the effect of tuning the energy and the ordering of the excited states on the photophysical properties of the dyad, especially the ISC and TADF properties, we introduced electron-donating and -withdrawing aryl

• characteristic absorption bands in the 300–375 nm range, which are attributed to the NI moiety, i.e., originating from the S0 → 1LE transition (Figure 1a). Moreover, in the range of 375–570 nm, there is a weak, broad absorption band centered at 460 nm, similar to the analogue NI-PTZ-C5 [39], which is assigned to

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• attributable to two methyl groups, two methoxy carbons, one methylene, three methines (one sp2 and one of them oxygenated), one ketone, and five sp2 carbons (two of them oxygenated). Some of these signals resemble those of 8-O-methylteratosphaerone B [17], suggesting compound 1 being an analogue, but with an

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• helical conformation was confirmed by the single-crystal X-ray crystallography of its methoxy-substituted analogue. Another method to obtain the incompletely cyclized seco-HBC is the introduction of a non-hexagonal ring into the precursors of HBC. Due to the large ring strain, the precursors are not prone

• compound 12. Meanwhile, Campaña, Morcillo, and co-workers converted the eight-membered ring 11 to nonagon-containing carbohelicene 14 through a single ring expansion reaction by treating 11 with TMSCHN2 (Scheme 2). By reacting with Tebbe’s reagent, compound 14 could be converted to all-carbon analogue 15

• structures were confirmed by single-crystal X-ray diffractometry and chiral HPLC. The rotational isomerization barrier of C6F4 ring for the analogue of 62, with two tert-butyl groups substituted by protons was determined as 24.6 kcal/mol at 40 °C with a half-life of t1/2 = 107 min. Employing the similar

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• disorders) [16] (Figure 2). 10,11-Dihydrodibenzo[b,f]azepine-based ligand 7 and a methyl analogue thereof are known to form pincer complexes with Pd, Ir, Rh and Ln [5], whereas a copper(II) wagon wheel complex of 8 was reported in a molecular organic framework (MOF) (Figure 3) [6]. 4,4'-(5-(Pyridin-2-yl

• resulted in a decreased yield. While fluoro groups were well tolerated, a major drawback of the method is the acid-catalysed dehalogenation of chloro- and bromo-substituted dibenzo[b,f]azepines. The brominated analogue was only isolated in 5% yield, compared to 67% for the unsubstituted 43. In addition

• -pyridobenzazepines 60b via cyclisation of 2,2'-dihalostilbene analogue 58 through a Pd-catalysed double Buchwald–Hartwig amination. The stilbene analogues 58 were prepared by a Wittig reaction with reported yields of the desired Z-isomer around 55%. The amination step was performed on a series of primary alkylamines

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• -hydroxycassa-11(12),13(15)-dien-12,16-olide (1) and 6′-acetoxypterolobirin B (3), together with a known analogue, identified as 12α,14β-dihydroxycassa-13(15)-en-12,16-olide (2), were isolated from the fruits of Pterolobium macropterum. Compound 1 is a cassane diterpenoid with a Δ11(12) double bond conjugated

• ′-acetoxypterolobirin B (3) together with one known analogue were isolated from the MeOH extract of P. macropterum fruits. Their structures and absolute configurations of 1 and 3 were established by spectroscopic analyses and ECD data. Compound 1 has an extended conjugated π-system with an α,β-unsaturated γ-lactone

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• °C in toluene for 1 h with 0.33 equiv of comp4 [Ru3(CO)11(PPh3)], a catalyst analogue to comp1 but bearing a less expensive phosphine ligand (Scheme 5A). The chosen ratio of imine to catalyst was consistent with the stoichiometric amounts needed to form the postulated intermediate. The temperature of

Dipeptide analogues of fluorinated aminophosphonic acid sodium salts as moderate competitive inhibitors of cathepsin C

• Karolina Wątroba,
• Małgorzata Pawełczak and
• Marcin Kaźmierczak

Beilstein J. Org. Chem. 2023, 19, 434–439, doi:10.3762/bjoc.19.33

• sodium salts 9 were more active against cathepsin C than β-fluorinated analogues 11. The dipeptide analogue of α-fluorinated aminophosphonic acid sodium salt bearing the valine residue as a second amino acid in the chain (9b) showed the greatest inhibitory power (Figure 1). The type of inhibition and the

Asymmetric synthesis of a stereopentade fragment toward latrunculins

• Benjamin Joyeux,
• Antoine Gamet,
• Nicolas Casaretto and
• Bastien Nay

Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32

• analogue synthesis, starting from (+)-β-citronellene. Key stereoselective transformations involve an asymmetric Krische allylation, an aldol reaction under 1,5-anti stereocontrol, and a Tishchenko–Evans reduction accompanied by a peculiar ester transposition, allowing to install key stereogenic centers of

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

• observed a coordination of the triflates along the C–I axis with distances of 2.705 Å (I1–O1) and 2.898 Å (I1–O5). For the ortho-methyl-substituted analogue 5ax, no halogen bonding to the triflates was observed, indicating an effective steric protection of the σ-holes [36]. Instead, there were only two

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

• from 2 equivalents of 99 and the cross metathesis adduct resulting from 99 and a styrene unit coming from the catalyst. In addition, the corresponding RCM on the alkene analogue of 99 did not proceed either with G-II or Schrock catalysts, showcasing the substrate sensitivity of this reaction. 1.3

Organophosphorus chemistry: from model to application

• György Keglevich

Beilstein J. Org. Chem. 2023, 19, 89–90, doi:10.3762/bjoc.19.8

• in organophosphorus chemistry. A series of P-stereogenic chiral thiophosphorus acids, such as a fused 1-hydroxytetrahydrophosphinine 1-sulfide, an oxaphosphinine sulfide analogue, and an azaphosphinine sulfide analogue were synthesized my Montchamp and Winters as potential organocatalysts [4]. The

A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• -deazaguanine In 1956, Markees and Kidder reported the first access to 1-deazaguanine [18], followed by a comparable approach one year later by Gorton and Shive [19]. Both started with the conversion of diethyl chelidamate 1 to its dicarbamate analogue 4 (Scheme 1) and further accomplished their syntheses

Solid-phase total synthesis and structural confirmation of antimicrobial longicatenamide A

• Takumi Matsumoto,
• Takefumi Kuranaga,
• Yuto Taniguchi,
• Weicheng Wang and
• Hideaki Kakeya

Beilstein J. Org. Chem. 2022, 18, 1560–1566, doi:10.3762/bjoc.18.166

• the evaluation of its antimicrobial activity. The present study confirmed our proposed structure of 1, which was determined by the use of our original labeling reagents [4]. Results and Discussion Although the solution-phase total synthesis of an analogue of longicatenamycin A has been reported [10

Synthesis of the biologically important dideuterium-labelled adenosine triphosphate analogue ApppI(d₂)

• Petri A. Turhanen

Beilstein J. Org. Chem. 2022, 18, 1466–1470, doi:10.3762/bjoc.18.153

• Petri A. Turhanen University of Eastern Finland, School of Pharmacy, Biocenter Kuopio, P.O. Box 1627, FIN-70211, Kuopio, Finland 10.3762/bjoc.18.153 Abstract The chemical synthesis of the dideuterium-labelled ATP analogue 1-adenosin-5’-yl-3-(3-methylbut-3-en-1,1-d2-1-ol) triphosphoric acid

• deuterium-labelled highly important ATP analogue ApppI(d2) has been described in detail. This leaves the possibility to develop a quantitative MS method for the determination of ApppI in biological samples by using ApppI(d2) as internal standard. Samples of ApppI(d2) are available from the author upon

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

• inhibitors to disrupt bacterial alginate production [3]. We recently disclosed the first series of targeted sugar nucleotide probes for GMD (Figure 1b) [4][5][6]. A C6-methyl analogue 6 was oxidised by GMD with direct evidence for a ketone product obtained. Most recently, C6-amide sugar nucleotide 7 was

On drug discovery against infectious diseases and academic medicinal chemistry contributions

• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 1355–1378, doi:10.3762/bjoc.18.141

• ][50] and chemistry-dependent. Indeed, if one can, with the right chemistry and insights, quite often provided by structural sciences, reach the really active and selective analogue then it was not a bad starting hit. Concerning the obviously useless hits, these can often be detected by proper control

• vivo [171] as well as the rescaffolded analogue ND-11543 (32) [168][169]. In view of this, further scaffold-hopping was undertaken [172][173], as illustrated by the structure of the pyridopyrazole 33 which is also featuring the long aryl-bearing chain of telacebec (22) [174]. Concerning the structure

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

• having electron-withdrawing groups (EWG) both at the 1 and 3-positions, namely 1,3-bis(ethoxycarbonyl)-1,3-azaphospholo[1,5-a]pyridine (1: R1 = R2 = COOEt) and its isoquinoline analogue, reacted with DMB and isoprene to give the [2 + 4] cycloadducts, in the latter case, regioselectively [11]. However, 2

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

• EtH-T-DI-DTT (1) is readily soluble in a dichloromethane/petroleum ether mixture to enable column chromatography. A similar reaction sequence with an analogue of 33 without α-methyl groups at the terminal positions of the molecules was attempted; however, the corresponding ring closure failed. It is

• asymmetric analogue, which is only alkylated on one side (9), achieved OFET hole mobilities up to 17.22 cm2 V−1 s−1 in polycrystalline films obtained by thermal evaporation [28]; both examples prove the potential of thienoacenes in OFETs. ITIC, a system with fused thiophenes, in combination with donor

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

• ]. In the same year, they also realized the synthesis of 2-phenyl-1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxide (55) in 75% yield by heating at 190–200 °C and in 47% yield by DCC condensation of compound 54 – the oxygen analogue of 2-aminobenzyl(phenyl)dithiophosphinic acid 58. The cyclodehydration

• similar alkyl transfer from the O to N atom followed by dehydration under heating (Scheme 11) [31]. Natchev prepared racemic and optically active ethyl 2-methyl-1,2-azaphospholidine-5-carboxylate 2-oxide (69) as cyclic analogue of the herbicide phosphinothricin (glufosinate, ᴅʟ-68) from ᴅʟ-, ᴅ-, and ʟ-2

Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures

• Mengjie Wang,
• Lanping Dang,
• Wan Xu,
• Zhiying Ma,
• Liuliu Shao,
• Guangxia Wang,
• Chunli Li and
• Hua Wang

Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81

• annulene [12], and twisted naphthalene as central spacers [19]. As its close analogue, selenophene has properties very similar to those of thiophene. Fused aromatic compounds containing selenophene units show favorable optical and electrochemical properties and improved charge transport characteristics in

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

• radicals under light irradiation for the diversification of arenes. To verify the generation of perfluoroalkyl radicals from compounds 1, we conducted an experiment with perfluorohexyl analogue 1b and 1,1-diphenylethylene (7) as a radical trapping agent (Scheme 4). Gratifyingly we observed the formation of

• -iodopropiophenone (6) and sodium perfluorohexylsulfinate (2b). Optimization for the perfluoroalkylation of aromatics under UV light. Supporting Information CCDC 2163755 contains the supplementary crystallographic data of byproduct B (perfluorooctyl analogue). These data can be obtained free of charge through the

Continuous flow synthesis of azobenzenes via Baeyer–Mills reaction

• Jan H. Griwatz,
• Anne Kunz and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2022, 18, 781–787, doi:10.3762/bjoc.18.78

• the preparation of large amounts of AB 1t (Scheme 2). This AB analogue was first synthesized by Masutani et al. in 2014 and was examined by them as well as in further studies by other groups regarding their potential for MOST applications, e.g., in a fluidic chip device by Wang et al. [1][26][27]. For

Cholyl 1,3,4-oxadiazole hybrid compounds: design, synthesis and antimicrobial assessment

• Anas J. Rasras,
• Mohamed El-Naggar,
• Nesreen A. Safwat and
• Raed A. Al-Qawasmeh

Beilstein J. Org. Chem. 2022, 18, 631–638, doi:10.3762/bjoc.18.63

• antibacterial property (Figure 1) [21]. In 2018, Sharma et al. presented a new pyridinyl-substituted cholic acid analogue that was effective against an epidemic strain of Clostridium difficile (Figure 1) [22]. Recently, Chuchkov et al. prepared a hybrid structure between heterocycle penciclovir and cholic acid

Synthesis of sulfur karrikin bioisosteres as potential neuroprotectives

• Martin Pošta,
• Václav Zima,
• Lenka Poštová Slavětínská,
• Marika Matoušová and
• Petr Beier

Beilstein J. Org. Chem. 2022, 18, 549–554, doi:10.3762/bjoc.18.57

• prepare the desmethyl analogue 26 through esterification of 6b with chloroacetyl chloride followed by intramolecular cyclization stayed unrewarded due to the lack of reactivity in the cyclization step. In order to overcome this problem a new strategy was developed. We combined the synthetic protocol of