The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

• Martin Vrbický,
• Karel Macek,
• Jaroslav Pochobradský,
• Jan Svoboda,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

• conditions. Asymmetric Henry reactions of aldehydes 16–20 with nitromethane catalyzed by copper(II) complexes of Ia, IIa, IIIa, and IV. Supporting Information Supporting Information File 38: General information and experimental data of all isolated products, copies of 1H and 13C NMR spectra for products and

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• byproducts in the system. For further confirmation, we have included the 13C NMR spectrum of the crude product 2a in Supporting Information File 1 (Figure S8). As a control experiment, the reaction was carried out in the absence of catalyst m-TPEWP5G with EsY alone (Figure S14, Supporting Information File 1

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• ), p-cresol (2f), 4-methoxyphenol (2g), 4-bromophenol (2h), 4-allyl-2-methoxyphenol (2i) are commercial reagents. Commercially available starting materials were used without further purification. The structures of synthesized products have been proven by 1H, 13C and 2D (NOESY, 1Н,13С HSQC, 1Н,13С HMBC

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• an interesting artifice to track the dimerization reaction path: they synthesized 2-(methyl-13C)-1,4-naphthoquinone (10) (Scheme 1) [81]. For that, sodium acetate-2-13C was used as the source of the methyl radical, generated by its treatment with K2S2O8 and AgNO3. After 3 hours at 60 °C, the 13C

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

• -28; δH 1.00, CH3-30), an oxymethine (δH 3.13, 1H, m) and a series of methylene multiplets located between δH 1.25 and δH 2.40. The 13C NMR and DEPT spectra exhibited the presence of 30 carbon signals, including a carbonyl group (δC 210.0), a tetrasubstituted double bond (δC 144.4 and 124.2), one

• powder with molecular formula C29H48O4, established by HREIMS at m/z 483.3446 [M + Na]+. The 1H and 13C NMR data (Table 1) of 2 exhibited very similar typical features of compound 1, the difference between the two compounds occurred in ring A: an OH was located at C-5, but a missing methyl group at C-4

• in 2, which was in agreement with the 13C NMR spectrum and the molecular mass. The hydroxylation at C-5 was deduced from the HMBC correlations (Figure 2) from H3-19/H-4 to C-5. Moreover, the HMBC correlations found from H-4 to C-5/C-6, H-7 to C-6, and H3-18/H3-21 to C-17 confirmed the location of a

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• the neighboring methyl group at the reaction center. The novel compounds 2a, 2b, and 3 were identified and characterized by NMR spectroscopy (1H, 13C, COSY, HSQC, HMBC), melting point, and elemental analysis. In addition, the structure of product 2b was supported by high resolution mass spectrometry

• most of them tend to decompose slowly in solution or during chromatographic work-up [31][34]. The novel compounds 5b–j were identified and fully characterized by NMR spectroscopy (1H, 13C, COSY, HSQC, HMBC); however, correct elemental analysis was not obtained in the case of the less-stable products 5d

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• measurement revealed a molecular ion at m/z 684.3969 [M + H]+, which suggests a molecular formula of C36H53N5O8 (calcd for C36H54N5O8, 684.3972) and corresponds with 13 degrees of unsaturation. An inspection of the 13C NMR spectrum confirmed the number of carbon atoms derived from the MS measurement (Table 1

• ppm). Therefore, compound 1 must feature three ring structures in order to comply with the required degrees of unsaturation. Proton–proton correlation spectroscopy (COSY) revealed four spin systems, which could be connected through 1H,13C long-range correlations (Figure 2) determined in a

• formula of C11H13NO5 was derived from a molecular ion at m/z 240.0890 [M + H]+ (calcd for C11H14NO5, 240.0877). An inspection of the 13C NMR spectrum confirmed the calculated number of carbon atoms (Table 2). Furthermore, a total of eight sp2-hybridized carbons can be assigned based on their chemical

A Se···O bonding catalysis approach to the synthesis of calix[4]pyrroles

• Qingzhe Tong,
• Zhiguo Zhao and
• Yao Wang

Beilstein J. Org. Chem. 2022, 18, 325–330, doi:10.3762/bjoc.18.36

• interactions between catalysts Ch1, Ch2 and acetone were examined by 13C NMR experiments in CD2Cl2. The interaction between bidentate catalyst Ch1 or monodentate catalyst Ch2 and acetone could result in a variation of the 13C signal of the carbonyl group. Analysis of a 1:1 mixture of Ch1 and acetone in CD2Cl2

• indicated a 1.07 ppm downfield shift of the 13C signal of the carbonyl group, while a 0.28 ppm downfield shift of the 13C signal of the carbonyl group was observed upon analysis of a 2:1 mixture of Ch2 and acetone (Scheme 4). Therefore, in line with the catalytic results as depicted in Scheme 2, both

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• monoamine product 47 further underwent intramolecular cyclization facilitated by the confinement of the cavitand and produced cyclized urea product 48. In a following work (Figure 13c) [78], the binding dibromide 49 showed rapid tumbling conformation in the cavity of the cavitand host E on the NMR timescale

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

• assigned in the 1H and 13C NMR spectra, allowing the complete spin system reconstruction for both the oxindole-based units. Furthermore, from NOESY experiment, the unique anti disposition of the two t-Bu–SO–NH substituents along the C3–C3’ bond could be assessed, thus demonstrating the complete

Iridium-catalyzed hydroacylation reactions of C1-substituted oxabenzonorbornadienes with salicylaldehyde: an experimental and computational study

• Angel Ho,
• Austin Pounder,
• Krish Valluru,
• Leanne D. Chen and
• William Tam

Beilstein J. Org. Chem. 2022, 18, 251–261, doi:10.3762/bjoc.18.30

• of MeOBD 13b with salicylaldehyde (14). Supporting Information Supporting Information File 143: Experimental procedures, compound characterization, and 1H and 13C NMR spectra of compounds. Supporting Information File 144: Cartesian coordinates and selected energy values for all calculated structures

Organocatalytic asymmetric nitroso aldol reaction of α-substituted malonamates

• Ekta Gupta,
• Narendra Kumar Vaishanv,
• Sandeep Kumar,
• Raja Krishnan Purshottam,
• Ruchir Kant and
• Kishor Mohanan

Beilstein J. Org. Chem. 2022, 18, 217–224, doi:10.3762/bjoc.18.25

• (100–200 mesh silica gel) using EtOAc/hexane as the eluent to afford product 4a as white solid (71 mg, 90%). Rf 0.20 (EtOAc/hexane 3:7); mp 115–117 °C; 1H NMR (400 MHz, CDCl3) δ 9.04 (s, 1H), 7.47–7.44 (m, 5H), 7.31–7.26 (m, 2H), 7.20–7.14 (m, 3H), 3.81 (s, 3H), 1.59 (s, 3H) ppm; 13C NMR (100 MHz

Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase

• Peterson de Andrade,
• Sanaz Ahmadipour and
• Robert A. Field

Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24

• 13C NMR experiment, where the α-anomer is a doublet and the β-anomer is a singlet [28]. The key intermediate 1 was further used in CuAAC reaction [29][30][31][32] with eleven (hetero)aromatic and non-aromatic terminal alkynes readily available in our lab [23]. Although CuAAC is reputedly tolerant of a

• structure of compounds 2a–h were confirmed by 1H and 13C NMR spectroscopy (see spectra in Supporting Information File 1) as well as HRESIMS analyses. The triazole ring hydrogen was observed as a singlet in the range δH 7.7–8.5 ppm and its corresponding carbon (CH-triazole) in the range δC 120–123 ppm

• sugars (final products) were lyophilised using a Büchi Lyovapor L-200 freeze dryer. 1H, COSY, 13C, DEPT-135 and HSQC NMR spectra were recorded on a Bruker Avance III 400 MHz spectrometer at 298 K. Chemical shifts (δ) recorded in CDCl3 and D2O are reported with respect to the solvent residual peak at 7.26

Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities

• Meifang Wu,
• Xiangdong Su,
• Yichuang Wu,
• Yuanjing Luo,
• Ying Guo and
• Yongbo Xue

Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23

• distinctive peaks for two anomeric protons at δH 5.71 (d, J = 7.7 Hz, H-1'') and 4.94 (d, J = 7.1 Hz, H-1'''), implied the co-existences of two sugar moieties. Analyses of the 13C NMR (Table 1) coupled with DEPT and HSQC spectra of 1 displayed 29 carbon signals assignable to two ester carbonyls (δC 161.3 and

• compounds Compound 1: Pale yellow powder; [α]D25 –38.05 (c 0.1, MeOH); UV (MeOH) λmax nm (log ε) 290 (0.35), 324 (0.32); IR νmax: 3266, 2925, 1739, 1701, 1624, 1457, 1261, 1020, 802, 611, 405 cm–1; 1H, 13C NMR data, see Table 1; ESIMS (positive ion mode): (m/z) 617 [M + H]+; HRESIMS (positive ion mode): (m

• key correlations observed in the 1H-1H COSY (bold bonds), HMBC (blue) correlations of 1 (recorded in pyridine-d5, 600 MHz). The key correlations observed in the 1H-1H COSY (bold bonds), HMBC (blue), ROESY (red) of 1 (recorded in DMSO-d6, 800 MHz). 1H and 13C NMR Spectroscopic Data for 1 (δ in ppm, J

High-speed C–H chlorination of ethylene carbonate using a new photoflow setup

• Takayoshi Kasakado,
• Takahide Fukuyama,
• Tomohiro Nakagawa,
• Shinji Taguchi and
• Ilhyong Ryu

Beilstein J. Org. Chem. 2022, 18, 152–158, doi:10.3762/bjoc.18.16

• °C, temperature change rate of 5 °C/min to 250 °C, hold at this temperature for 10 min. Yields were determined by using the percentage peak area method with compensation for the relative sensitivities of each component. Product 2 and byproduct 2’ were confirmed by 1H and 13C NMR analysis (see

Ready access to 7,8-dihydroindolo[2,3-d][1]benzazepine-6(5H)-one scaffold and analogues via early-stage Fischer ring-closure reaction

• Irina Kuznetcova,
• Felix Bacher,
• Daniel Vegh,
• Hsiang-Yu Chuang and
• Vladimir B. Arion

Beilstein J. Org. Chem. 2022, 18, 143–151, doi:10.3762/bjoc.18.15

• , characterization data and 1H and 13C NMR spectra of compounds, NMR numbering schemes and X-ray crystallography data. Acknowledgements We also thank Mr. Alexander Roller and Ms. Natalie Gajic for collection of X-ray diffraction data. Funding Support from the Austrian Science Fund (FWF) (P31293-N37) and Slovak

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

• with this methodology, as shown in Figure 5. The synthesized products were characterized by 1H NMR, 13C NMR, HRMS, and melting point analysis. The structure of the compounds was also confirmed by single-crystal XRD analysis of 4a (CCDC1949329, Figure 6). Plausible mechanism A plausible reaction

• TAKASHI ultrasonic cleaning bath, and the progress of the reactions was monitored by TLC analysis using silica gel. 1H and 13C NMR spectra were recorded on Bruker 300 MHz and 400 MHz instruments using CDCl3, with TMS as internal reference. Melting points were recorded on an electrical melting point

Tenacibactins K–M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum

• Yasuhiro Igarashi,
• Yiwei Ge,
• Tao Zhou,
• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku and
• Agus Trianto

Beilstein J. Org. Chem. 2022, 18, 110–119, doi:10.3762/bjoc.18.12

• adduct [M + Na]+ at m/z 678.4412 (Δ + 0.0 mmu for C33H61N5O8Na). Analysis of 13C NMR and HSQC spectroscopic data obtained in DMSO-d6 established the presence of five carbonyl carbons (δC 166.2, 168.6, 171.0, 171.5, 172.0), two sp2 methines (δC 119.8, 144.5), one sp3 methine (δC 27.5), two magnetically

• in 1. Among the five amide bonds, amide protons were present at N21 and N32, thereby leaving N15, N26, and N37 as the hydroxylation sites. This assignment was supported by the 13C NMR chemical shifts. Within each cadaverine moiety, the 13C chemical shifts for the methylenes adjacent to the N

• ): pale brown powder; UV (MeOH) λmax nm (log ε): 201 (4.82) nm; IR (ATR) νmax: 3305, 2916, 2849, 1613, 1538, 1466 cm−1; 1H and 13C NMR, Table 1; HR–ESITOFMS (m/z): [M − H]− calcd for C33H60N5O8, 654.4447; found, 654.4449; [M + Na]+ calcd for C33H61N5O8Na, 678.4412; found, 678.4412. Tenacibactin L (2

Regioselective synthesis of methyl 5-(N-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates as new amino acid-like building blocks

• Jolita Bruzgulienė,
• Greta Račkauskienė,
• Aurimas Bieliauskas,
• Vaida Milišiūnaitė,
• Miglė Dagilienė,
• Gita Matulevičiūtė,
• Vytas Martynaitis,
• Sonata Krikštolaitytė,
• Frank A. Sløk and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2022, 18, 102–109, doi:10.3762/bjoc.18.11

• analysis, 1H, 13C, and 15N NMR spectroscopy, HRMS, and single-crystal X-ray diffraction data. Keywords: β-enamino ketoesters; heterocyclic amino acids; 15N-labeled 1,2-oxazole; NMR (1H; 13C; 15N); 1,2-oxazole (isoxazole); X-ray structure analysis; Introduction 1,2-Oxazoles (isoxazoles) constitute an

• ). The 1H NMR spectrum of compound 3a showed the appearance of a new downfield enamine proton signal which resonated at δ 7.80 ppm. The connectivity of the β-enamino ketoester moiety and the N-Boc-protected azetidine fragment were easily confirmed based on long-range 1H,13C correlations, obtained from gs

• 4.32 ppm (J = 8.8 Hz), while the methine proton (3’-H) yielded a triplet of triplets at δ 4.48 ppm (J = 8.9, 6.5 Hz). A comparison between the DEPT-90, DEPT-135 and 13C NMR spectra of compound 4a clearly indicated the presence of methine carbons C-3 (δ 150.6 ppm) and C-3’ (δ 26.1 ppm), respectively

Chemical and chemoenzymatic routes to bridged homoarabinofuranosylpyrimidines: Bicyclic AZT analogues

• Sandeep Kumar,
• Jyotirmoy Maity,
• Banty Kumar,
• Sumit Kumar and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2022, 18, 95–101, doi:10.3762/bjoc.18.10

• , 13C NMR, 1H,1H-COSY NMR, 1H,13C-HETCOR NMR, NOESY NMR and HRMS) data analysis. The structures of known compounds 11 and 17 were further confirmed by comparison of their physical and spectral data with those reported in literature [28]. Conclusion The efficiency of Lipozyme® TL IM was discovered for

Efficient and regioselective synthesis of dihydroxy-substituted 2-aminocyclooctane-1-carboxylic acid and its bicyclic derivatives

• İlknur Polat,
• Selçuk Eşsiz,
• Uğur Bozkaya and
• Emine Salamci

Beilstein J. Org. Chem. 2022, 18, 77–85, doi:10.3762/bjoc.18.7

• HCl(g) in MeOH (Scheme 1). N-Boc protection of cis-amino ester 3 with (Boc)2O in pyridine and 4-(dimethylamino)pyridine (DMAP) gave N-Boc-amino ester 4 (yield 95%). The 1H and 13C NMR spectroscopic data of 4 were in agreement with the proposed structure. Treatment of 4 with OsO4/NMO gave the expected

• diol 5 as a single isomer in 91% yield. We assume that the trans selectivity of hydroxylation in ester 4 is due to the steric effect of the presence of the bulky Boc group. The structure of 5 was determined with the help of 1D (1H and 13C) and 2D (COSY and HMQC) NMR spectra. The diagonal peak at 4.10

• Information Experimental section, 1H and 13C NMR spectra for all new compounds, as well as selected 2D NMR spectra and crystallographic data for compound 10 are provided. Optimized geometries of the transition states with selected interatomic distances and cartesian coordinates for computed structures are

Efficient synthesis of ethyl 2-(oxazolin-2-yl)alkanoates via ethoxycarbonylketene-induced electrophilic ring expansion of aziridines

• Yelong Lei and
• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 70–76, doi:10.3762/bjoc.18.6

• were conducted on a CEM discovery SP microwave reactor. The plates were visualized under UV light, as well as other TLC stains. 1H, 13C, and 31P NMR spectra were recorded on a Bruker 400 MHz spectrometer in CDCl3 with solvent peaks as internal standards, for 31P NMR, 85% H3PO4 as an external standard

• Information Supporting Information File 10: Analytic data and copies of 1H, 13C, and 31P NMR spectra of compounds 3. Funding This research was supported by the National Natural Science Foundation of China (Nos. 21572017 and 21772010).

Bifunctional thiourea-catalyzed asymmetric [3 + 2] annulation reactions of 2-isothiocyanato-1-indanones with barbiturate-based olefins

• Jiang-Song Zhai and
• Da-Ming Du

Beilstein J. Org. Chem. 2022, 18, 25–36, doi:10.3762/bjoc.18.3

• silica gel (200–300 mesh). Melting points were determined with an XT-4 melting-point apparatus and are uncorrected. 1H NMR spectra were measured with a Bruker Ascend 400 MHz spectrometer, chemical shifts are reported in δ (ppm) units relative to tetramethylsilane (TMS) as an internal standard. 13C NMR

The enzyme mechanism of patchoulol synthase

• Houchao Xu,
• Bernd Goldfuss,
• Gregor Schnakenburg and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 13–24, doi:10.3762/bjoc.18.2

• contradictory. For this reason, we have reinvestigated the enzyme mechanism of PTS in isotopic labelling experiments through methods recently developed in our laboratory that make use of 13C and 2H-substituted terpene precursors, and by DFT calculations. The general strategy in these experiments is to use

• substrates or substrate combinations so that deuterium migrations end at 13C-labelled carbons, resulting in triplet signals in the 13C NMR spectra [15][16]. Moreover, deuterium atoms ending in neighbouring positions of 13C-labelled carbons become evident from slight upfield shifted 13C NMR signals. These

• S3). Using dimethylallyl diphosphate (DMAPP) and (E)- and (Z)-(4-13C,4-2H)isopentenyl diphosphate (IPP) [18] in conjunction with FPP synthase (FPPS) from Streptomyces coelicolor [19] and PTS (Supporting Information File 1, Figure S11), stereogenic centres of known configuration are introduced at the

Stepwise PEG synthesis featuring deprotection and coupling in one pot

• Logan Mikesell,
• Dhananjani N. A. M. Eriyagama,
• Yipeng Yin,
• Bao-Yuan Lu and
• Shiyue Fang

Beilstein J. Org. Chem. 2021, 17, 2976–2982, doi:10.3762/bjoc.17.207

• 1H and 13C NMR, and MS of new compounds. Funding National Science Foundation (1918585 and 1754235; and equipment grants 1048655, 9512455, 1531454), Robert and Kathleen Lane Endowed Fellowship (D.N.A.M.E.), David and Valeria Pruett Fellowship (D.N.A.M.E.), Michigan Tech HRI Research Fellowship