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

• ) δ 7.55–7.37 (m, 15H); 31P NMR (162 MHz, CDCl3) δ 35.06; XPS BE Ru 3d5/2 (281.58). These data are in good agreement with those reported in literature. Crystals were grown from a solution in Et2O and identified by X-ray diffraction as a known phase of comp4 [41]. General procedure for C3-alkylation of

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• was used to isolate the known compound corniculatolide A (4, 10 mg) as colorless crystals [14]. Later the same group reported the isolation of corniculatolide B (9), isocorniculatolide B (10), and corniculatolide C (11) from Xylocarpus granatum, a tree commonly found in Southeast Asia and along the

An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies

• Tharun K. Kotammagari,
• Sweta Misra,
• Sayantan Paul,
• Sunita Kunte,
• Rajesh G. Gonnade,
• Manas K. Santra and
• Asish K. Bhattacharya

Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19

• structure of rac-incarvilleatone (1) was determined by spectroscopic methods and single crystal X-ray analysis. However, they were unable to obtain single crystals of either of the enantiomers (−)-incarvilleatone [(−)-1] and (+)-incarvilleatone [(+)-1]. (±)-Incarviditone (2), a novel benzofuranone dimer was

• 331.1150 corresponding to the C16H20O6Na [M + Na]+ ion. After some efforts, to our delight, we could obtain single crystals of (±)-4 using EtOAc as a solvent. Finally, the formation of heterodimerized dihydroxy RC product (±)-4 was confirmed by single-crystal X-ray analysis [16]. It is pertinent to mention

Synthesis and characterisation of new antimalarial fluorinated triazolopyrazine compounds

• Kah Yean Lum,
• Jonathan M. White,
• Daniel J. G. Johnson,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2023, 19, 107–114, doi:10.3762/bjoc.19.11

• ethanol using the standard nucleophilic displacement method as previously described (Scheme 1) [14][16]. Structures of synthesised compounds 4–9 were determined using 1D/2D NMR and HRMS (Supporting Information File 1, S6–S23). Crystals of compounds 5 and 6 were also analysed by X-ray crystallography

• to H-20, H-24 and H-6 (δH 7.49). The presence of a benzonitrile ring at the C-3 position was supported by the HMBC correlations of aromatic protons δH 7.68 (H-11, H-15) to C-3 (δC 146.2), and δH 7.64 (H-12, H-14) to C-16 (δC 118.0). Furthermore, crystals obtained for compound 18 were analysed by X

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

• Christian Schumacher,
• Jas S. Ward,
• Kari Rissanen,
• Carsten Bolm and
• Mohamed Ramadan El Sayed Aly

Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

• synthetic chemistry was expanded to click conjugates such as II and III, and the data was reported [10]. Recently, those studies were revisited, and we now obtained single crystals which allowed to unequivocally establishing the relative configurations of the products by X-ray crystallography. Accordingly

• different mesh numbers. Single crystals of both were obtained by slow evaporation from diethyl ether. The less polar, minor material gave ice-white needles, and an X-ray single crystal structure determination revealed the product to be cholesta-3,5-diene (9, Figure 3). The 1H NMR data of 9 are in full

• crystals obtained from Et2O, which showed the product to be 3α-azidocholest-5-ene (5, Figure 5) [18][19]. Thus, under the aforementioned conditions, 3β-bromocholest-5-ene (4) was predominantly converted into 3α-azidocholest-5-ene (5) involving a stereospecific transformation at C3 proceeding with a Walden

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

• Bilge Banu Yagci,
• Selin Ezgi Donmez,
• Onur Şahin and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

• ]. In the present work, the α-methylene-γ-lactam products 19 were in most cases isolated as oils after column chromatography. Fortunately, lactam product 19l turned out to be a solid, and high-quality crystals could be obtained via slow vapor diffusion of pentane into its CH2Cl2 solution. Single-crystal

Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

• Alexios I. Vicatos,
• Zakiena Hoossen and
• Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

• -CD·BES, β-CD·PRO, γ-CD·BES and γ-CD·PRO were prepared via kneading and co-precipitation, and 1H NMR spectroscopic analysis of solutions of their pure complex crystals yielded the host–guest stoichiometries 2:1, 2:1, 1:1 and 3:2, respectively. Both powder X-ray diffraction (PXRD) and single-crystal X-ray

• (Figures S1 and S2 in Supporting Information File 1). This method enabled initial assignment of the space group for each new complex and estimation of its unit cell parameters, these data being subsequently confirmed by single crystal X-ray diffraction for those complexes that formed crystals of adequate

• size and quality. Co-precipitation experiments yielded single crystals of all four CD inclusion complexes with distinctive transparent monoclinic morphologies for β-CD·BES and β-CD·PRO, and transparent rods with a square cross-section for γ-CD·BES and γ-CD·PRO (Figure 4). PXRD analysis also confirmed

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• and the flow rate of the solution, allowing for conditions to be created to best approximate the ideal growth curve through the metastable zone (where controlled crystal growth occurs). Single crystals of paracetamol were obtained to prove this crystallization method. The application of inline

• segmented droplets) and the temperature were needed to obtain suitable crystals without reactor fouling. The droplets and crystals were monitored using an inline phototransistor and a video microscope. Finally, crystals were collected by filtration. In another protocol, a continuous crystallization was

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

• Konstantin Lebedinskiy,
• Volodymyr Lobaz and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

• filtered off the formed crystals, took 50 and 100 μL of the solution, diluted them to 1 mL, and measured the UV spectra. A comparison with the calibration plot determined the concentration of the tetracene. Thus, we estimated tetracene's solubility in DMSO to be 0.71 mg/mL at room temperature. The

A facile approach to spiro[dihydrofuran-2,3'-oxindoles] via formal [4 + 1] annulation reaction of fused 1H-pyrrole-2,3-diones with diazooxindoles

• Pavel A. Topanov,
• Anna A. Maslivets,
• Maksim V. Dmitriev,
• Irina V. Mashevskaya,
• Yurii V. Shklyaev and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2022, 18, 1532–1538, doi:10.3762/bjoc.18.162

• the solution being turned from purple to red. The starting FPD 1a is bright violet; thus, the disappearance of the violet color was used as an indicator of the reaction’s completion. Product 3aa was isolated as yellow crystals in 73% yield and characterized by NMR, IR, and mass spectra, and single

Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance

• Ruslan P. Shekurov,
• Mikhail N. Khrizanforov,
• Ilya A. Bezkishko,
• Tatiana P. Gerasimova,
• Almaz A. Zagidullin,
• Daut R. Islamov and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157

• vacuo. The product was extracted with benzene (3 × 30 mL) and after evaporation of the solvent triferrocenyl trithiophosphite (1.34 g, 76%) was obtained as a yellow powder. Single crystals suitable for X-ray diffraction were obtained by dissolving the compound in a mixture of benzene/hexane 1:1 and

• diffraction The data set for single crystals of triferrocenyl trithiophosphite was collected on a Rigaku XtaLab Synergy S instrument with a HyPix detector and a PhotonJet microfocus X-ray tube using Cu Kα (1.54184 Å) radiation at 100 K. Images were indexed and integrated using the CrysAlisPro data reduction

• )3PS [7] (Figure 4). All three compounds form crystals belonging to the monoclinic syngony. In all three cases, the molecules in the crystals form a herringbone motif. In (FcS)3P, C–H···π interactions dominate, while in (FcS)3PS and (FcS)3PO, in addition to C–H···π interactions, by one C–H···S and two

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

• minimum volume of hot EtOH, enabling solid state analysis (Figure 2). Crystals of 16 were analysed by single crystal X-ray diffraction and the data were solved in the monoclinic space group P21. Although the crystals suffered from intrinsic non-merohedral twinning through a non-crystallographic rotation

Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups

• Neda Rafieiolhosseini,
• Matthias Killa,
• Thorben Neumann,
• Niklas Tötsch,
• Jean-Noël Grad,
• Alexander Höing,
• Thies Dirksmeyer,
• Jochen Niemeyer,
• Christian Ottmann,
• Shirley K. Knauer,
• Michael Giese,
• Jens Voskuhl and
• Daniel Hoffmann

Beilstein J. Org. Chem. 2022, 18, 1322–1331, doi:10.3762/bjoc.18.137

• novel luminophores tailor-made for different applications. One unique, promising class of compounds, the so-called aggregation-induced emitters (AIE) have been used for a wide range of applications, e.g., in OLEDs, liquid crystals [17], stimuli responses, bioassays, protein and ion detection or imaging

Synthesis of tryptophan-dehydrobutyrine diketopiperazine and biological activity of hangtaimycin and its co-metabolites

• Houchao Xu,
• Anne Wochele,
• Minghe Luo,
• Gregor Schnakenburg,
• Yuhui Sun,
• Heike Brötz-Oesterhelt and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 1159–1165, doi:10.3762/bjoc.18.120

• 0.102, MeOH). The reason for the varying melting points for 4 in the literature is unclear, but we noticed a pronounced difference in the crystallisation behaviour of racemic and enantiomerically pure 4. While (rac)-4 readily formed crystals (mp 134–136 °C), several attempts to crystallise (S)-4, a

Scope of tetrazolo[1,5-a]quinoxalines in CuAAC reactions for the synthesis of triazoloquinoxalines, imidazoloquinoxalines, and rhenium complexes thereof

• Laura Holzhauer,
• Chloé Liagre,
• Olaf Fuhr,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2022, 18, 1088–1099, doi:10.3762/bjoc.18.111

• the reactions takes place first and is required for the second reaction or whether both reactions occur independently of each other. Single crystals for 25b were obtained from slow evaporation of methanol under ambient pressure and the assumed structure of the TIQ product could unambiguously be

• obtained products. Single crystals for complexes 27a–d were obtained via slow evaporation of a solution in either methylene chloride, ethyl acetate, or deuterated chloroform under ambient conditions. The rhenium atom is coordinated to three carbonyl groups, the bromine atom and two nitrogens of the 1,2,3

• -triazoloquinoxaline ligand in a distorted octahedral coordination geometry in all cases. The obtained data for the alkyl-chain complex 27a corresponds to similar published results [12]. For complex 29, single crystals were formed from slow evaporation of a methylene chloride solution under ambient conditions. The

Synthesis, optical and electrochemical properties of (D–π)₂-type and (D–π)₂Ph-type fluorescent dyes

• Kosuke Takemura,
• Kazuki Ohira,
• Taiki Higashino,
• Keiichi Imato and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

• , compared with those in toluene. The Φfl-solid (0.24) of OTT-2 is higher than that (Φfl-solid = 0.15) of OTK-2, while the Φfl-solid of OTK-2 and OTT-2 are lower than those in toluene. Although single crystals of OTK-2 and OTT-2 with sufficient size for X-ray structural analysis were not obtained, the

• This work was supported by the Grant-in-Aids for Scientific Research on Innovative Areas “Soft Crystals” (No. 2903) (JSPS KAKENHI Grant No. 18H04520) and the Suga Weathering Technology Foundation.

Electrochemical and spectroscopic properties of twisted dibenzo[g,p]chrysene derivatives

• Tomoya Imai,
• Ryuhei Akasaka,
• Naruhiro Yoshida,
• Toru Amaya and
• Tetsuo Iwasawa

Beilstein J. Org. Chem. 2022, 18, 963–971, doi:10.3762/bjoc.18.96

• , dyes, liquid crystals, and light-emitting materials. A number of substituted DBCs have been reported in this context [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. To develop charge-transport materials, Rathore et al. reported on the stability of radical cations of

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

• highly delocalised bipolaron states [69]. Computation of structure Since all attempts to grow crystals of EtH-T-DI-DTT failed, we predicted the structure with a density functional theory (DFT) gas-phase optimisation using the B3LYP[70][71]/6-311g(d,p) [72] level of theory, using both the Gaussian09 [73

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• worth determining their absolute configuration. Unfortunately, our efforts to obtain suitable crystals for X-ray diffraction analysis were unsuccessful. The lack of secondary hydroxy groups in these molecules prevented the use of chemical approaches. In addition, their weak Cotton effects (Figure 5

Synthesis of novel alkynyl imidazopyridinyl selenides: copper-catalyzed tandem selenation of selenium with 2-arylimidazo[1,2-a]pyridines and terminal alkynes

• Mio Matsumura,
• Kaho Tsukada,
• Kiwa Sugimoto,
• Yuki Murata and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 863–871, doi:10.3762/bjoc.18.87

• the three components (Se powder, 1a, and 3a) in the presence of Na2CO3 at 130 °C, but unfortunately it did not proceed and gave a complex mixture (Table 1, entry 13). Single crystals suitable for X-ray analysis of 4aa were obtained by repeated recrystallization from dichloromethane/hexane as solvent

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

• compound 14 respectively with B(C6F5)3 and B(C6H5)3 by X-ray photoelectron spectroscopy (XPS) [29]. The B(1s) signal showed peaks at 190.61 and 191.08 eV, respectively. This is close to the reported characteristic B–N binding energy (190.5 eV) in B–N crystals. Despite the weak signals of boron in these two

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

• crystallographic analyses were performed using crystals of compounds DH-1 and DH-2 with sizes of 0.14 × 0.12 × 0.08, 0.21 × 0.17 × 0.12 mm3, respectively. The intensity data were collected with the ω scan mode (296 K) on a diffractometer with a CCD detector using Cu Kα radiation (λ = 1.54184 Å). The data were

• solutions of DH-1 and DH-2 in CHCl3/CH3OH 5:1 (v/v) were employed for growing single crystals. The fluorescence quantum yields (ΦF) of DH-1–3 are characterized in dichloromethane with quinine sulfate in 0.1 N H2SO4 as the control. Synthesis of 5a–c and DH-1–3 Synthesis of 1,3-bis(2-(5-(trimethylsilyl

Four bioactive new steroids from the soft coral Lobophytum pauciflorum collected in South China Sea

• Di Zhang,
• Zhe Wang,
• Xiao Han,
• Xiao-Lei Li,
• Zhong-Yu Lu,
• Bei-Bei Dou,
• Wen-Ze Zhang,
• Xu-Li Tang,
• Ping-Lin Li and
• Guo-Qiang Li

Beilstein J. Org. Chem. 2022, 18, 374–380, doi:10.3762/bjoc.18.42

• mg), 6 (15.5 mg) and 7 (10.2 mg). Fr.412 (210 mg) was chromatographed on semi-preparative HPLC (ODS, 5 µm, 250 × 10 mm; methanol/water, 85:15, v/v; 2.0 mL/min) to give compound 1 (2.5 mg), 2 (5.8 mg) and 3 (13.3 mg). Identification of new compounds Compound 1: colorless crystals; [α]D25 −19.28 (c

• 0.13, MeOH); IR (KBr) νmax: 3389, 2944, 2871, 1707, 1603, 1467, 1380 cm−1; 1H and 13C NMR data (CDCl3, 500 and 125 MHz) see Table 1; HRESIMS (m/z) [M + Na]+ calcd for C30H50O3Na, 481.3652; found, 481.3648. Compound 2: colorless crystals; [α]D25 −12.77 (c 0.3, MeOH); IR (KBr) νmax: 3361, 2926, 2855

• , 1702, 1651, 1459, 1376 cm−1; 1H and 13C NMR data (CD3OD, 500 and 125 MHz) see Table 1; HRESIMS (m/z) [M + Na]+ calcd for C29H48O4Na, 483.3445; found, 483.3446. Compound 3: colorless crystals; [α]D25 −18.36 (c 0.5, MeOH); IR (KBr) νmax: 3390, 2938, 1702, 1459, 1376 cm−1; 1H and 13C NMR data (CDCl3, 500

Unexpected chiral vicinal tetrasubstituted diamines via borylcopper-mediated homocoupling of isatin imines

• Marco Manenti,
• Leonardo Lo Presti,
• Giorgio Molteni and
• Alessandra Silvani

Beilstein J. Org. Chem. 2022, 18, 303–308, doi:10.3762/bjoc.18.34

• diastereoselectivity of the reaction (see Supporting Information File 1). All stereochemical implications were fully confirmed by single-crystal X-ray diffraction analysis, which was performed on well-formed prismatic crystals of compound 2a (Figure 1) [28]. Compound 2a is chiral and crystallizes in the orthorhombic

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

• Information File 1 (Figures S38–S47). Single crystals of compound 3ba were obtained by slow evaporation of a CDCl3 solution at 25 °C. Diffraction measurement of compound 3ba was performed using a Bruker D8 QUEST diffractometer using Cu Kα radiation (λ = 1.54178 Å) with a KAPPA four-circle goniometer equipped