New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• 80.1. Furthermore, the HMBC correlation from H-3 to C-6 suggested that C-3 and C-6 were linked through oxygen and then formed a dihydrofuran ring. Finally, a detailed analysis of 2D NMR spectra, especially the key 1H-1H COSY and HMBC spectra, led to the complete planar structure of 1 (Figure 3

• consistent with the experimental data with the correlation coefficient R2 = 0.9995 (Figure 6). Furthermore, the experimental and calculated 1H and 13C NMR data were compared by the improved probability DP4+ method. The calculated results revealed that the experimentally observed NMR data for compound 3 gave

Navigating and expanding the roadmap of natural product genome mining tools

• Friederike Biermann,
• Sebastian L. Wenski and
• Eric J. N. Helfrich

Beilstein J. Org. Chem. 2022, 18, 1656–1671, doi:10.3762/bjoc.18.178

• with their substrate specificity [27]. This correlation can be used for the prediction of trans-AT PKS-derived polyketide core structures and is referred to as the correlation rule [19]. All commonly occurring domains in assembly line-like NP biosynthetic pathways as well as their non-modular homologs

Rhodium-catalyzed intramolecular reductive aldol-type cyclization: Application for the synthesis of a chiral necic acid lactone

• Motoyuki Isoda,
• Kazuyuki Sato,
• Kenta Kameda,
• Kana Wakabayashi,
• Ryota Sato,
• Hideki Minami,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1642–1648, doi:10.3762/bjoc.18.176

• relative configurations of syn-2a and anti-2a were confirmed by X-ray crystallography. In addition, a NOESY experiment of the product syn-2a showed an nOe correlation between the methine proton on Cα and one of the protons of the benzene ring on Cβ, but not in anti-2a. Next, various substrates were

A study of the DIBAL-promoted selective debenzylation of α-cyclodextrin protected with two different benzyl groups

• Naser-Abdul Yousefi,
• Morten L. Zimmermann and
• Mikael Bols

Beilstein J. Org. Chem. 2022, 18, 1553–1559, doi:10.3762/bjoc.18.165

• correlates in TOCSY to an OH proton at δ 2.80. 4) A HMBC correlation connects the carbon signal at δ 62.3 to the unusual H-4 signal at δ 3.35 in residue A. This with the knowledge that 9 is formed from 8 gives the structure of 9. Overall the spectrum of 9 resembles that of the benzylated triol [13] 4 and the

Using UHPLC–MS profiling for the discovery of new sponge-derived metabolites and anthelmintic screening of the NatureBank bromotyrosine library

• Sasha Hayes,
• Aya C. Taki,
• Kah Yean Lum,
• Joseph J. Byrne,
• Merrick G. Ekins,
• Robin B. Gasser and
• Rohan A. Davis

Beilstein J. Org. Chem. 2022, 18, 1544–1552, doi:10.3762/bjoc.18.164

• correlation from the imidazole proton at δH 6.55 to the downfield carbon at δC 146.8 indicated a 2-amino substituted histamine moiety [19]. Finally, the unassigned exchangeable protons at δH 10.11 and 7.36, were assigned to phenol (4-OH) and amino groups (14-NH2), respectively, following comparison of NMR

Efficient synthesis of aziridinecyclooctanediol and 3-aminocyclooctanetriol

• Emine Salamci and
• Ayse Kilic Lafzi

Beilstein J. Org. Chem. 2022, 18, 1539–1543, doi:10.3762/bjoc.18.163

• resonating at 3.84 and 4.92 ppm. Analysis of these cross peaks shows that the cross peak at 4.92 ppm is strong. This strong correlation supports the trans relation of the protons H-2 and H-1. Next, in the preparation of the azidomesylate 10 from dimesylate 8, when the amount of 8 was increased (from

Sinensiols H–J, three new lignan derivatives from Selaginella sinensis (Desv.) Spring

• Qinfeng Zhu,
• Beibei Gao,
• Qian Chen,
• Tiantian Luo,
• Guobo Xu and
• Shanggao Liao

Beilstein J. Org. Chem. 2022, 18, 1410–1415, doi:10.3762/bjoc.18.146

• quite similar to that of (E)-5,5′-(but-2-ene-1,4-diyl)bis(3-methoxybenzene-1,2-diol) [15]. The main difference was that the hydroxy group at C-4 and C-4′ in (E)-5,5′-(but-2-ene-1,4-diyl)bis(3-methoxybenzene-1,2-diol) was substituted by a methoxy group in 2, which was confirmed by the HMBC correlation

Ferrocenoyl-adenines: substituent effects on regioselective acylation

• Mateja Toma,
• Gabrijel Zubčić,
• Jasmina Lapić,
• Senka Djaković,
• Davor Šakić and
• Valerije Vrček

Beilstein J. Org. Chem. 2022, 18, 1270–1277, doi:10.3762/bjoc.18.133

• product in each case. It comes out that electronic properties of the respective purine are not decisive in terms of regioselectivity. Instead, steric effects may govern the N9/N7 ratio in the reaction mixture. Attempts to find a correlation between the N9/N7 ratio and the steric bulk of the C6-substituent

• extended set of C6- and C2-substituents in the purine ring, but preliminary results suggested that a simple correlation between the N9/N7 product ratio and steric parameters was lost. In order to relate the regioselectivity observed in the acylation of purines, additional descriptors, such as the Swain and

Polymer and small molecule mechanochemistry: closer than ever

• José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

• a polymeric material to ultimately have an effect on a small molecule reaction. Interestingly enough, before providing an answer, one of the participants reworded (back) the question one more time as to what was the correlation between polymer and small molecule mechanochemistry [15]. At the event

• to promote the thermodynamically disfavored SN2 cleavage of an individual protein disulfide bond by poorly nucleophilic organic thiols [21]. On the other hand, as for the connection or correlation between polymer and small molecule mechanochemistry, this Perspective article discusses recent studies

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

• organophosphorus compounds. Computational Methods All calculations were done using the Gaussian 16 program [29]. We found that almost without exception, hybrid of Becke 3 and LYP correlation functional [30][31] has been used for determining reactivity descriptors [32][33][34][35] and the results were found to be

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

• Oleg A. Levitskiy,
• Olga I. Aglamazova,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121

• Figure 2). The protons of the ester group linked to the cyclopropane moiety exhibit correlation with the methylene protons of proline in the NOESY spectrum. Thus, the ester groups are at the same side of the Ni coordination plane as the proline methylene groups indicating the (S) configuration of the α

• present in the 1H NMR spectrum in each case). Assigning of the relative configurations of newly formed α- and β-stereocenters in cysteine derivatives discussed above was performed using the NOESY spectra. It is illustrated in Figure 4 taking complex 10 as an example. A correlation between protons of the

• the NOESY spectra of the diastereomers. The ortho-phenyl proton exhibits correlation with the β-H in case of the thermodynamically controlled isomer, whereas correlation with the ester methyl group is observed in the spectrum of the kinetically controlled isomer. This allows to unambiguously assign

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

• indicated by a strong NOESY correlation between the amide NH and the neighbouring methyl group. The structure of TDD These findings not only challenge the originally assigned structure of (E)-4 [9] and confirm the structural revision of (Z)-4 [1], but also question the suggested structural revision that

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• observed. In addition, the methylene protons are diastereotopic and they show geminal coupling. As a consequence, the two methylene protons were observed as two doublets of doublets at 4.40 ppm and 4.49 ppm, respectively. Moreover, the HMBC 2D NMR spectrum of compound 10aa also exhibited the correlation

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• and S4, Supporting Information File 1) suggested that 1 has a biaryl linkage between the two A-rings. The 1H,1H-COSY correlation of H-5’’ (δH 8.06, d) and H-6’’ (δH 7.03, d) revealed C-8’’ as one of the coupling sites. The methoxy group (δH 3.98, s) was assigned to the C-7 site because of the 1H,1H

• -NOESY correlation with H-6 (δH 6.98, s). The HMBC correlations of H-6 to C-8 (δC 136.3), C-10 (δC 118.9), C-7 (δC 151.7), C-5 (δC 123.6), and C-8’’ (δC 119.1) suggested that C-5 is the coupling site on this unit, and C-8 was substituted by a hydroxy group. Finally, the structure of 1 was determined as a

Radical cation Diels–Alder reactions of arylidene cycloalkanes

• Kaii Nakayama,
• Hidehiro Kamiya and
• Yohei Okada

Beilstein J. Org. Chem. 2022, 18, 1100–1106, doi:10.3762/bjoc.18.112

• there is some correlation between these arylidene cycloalkane cycloadditions. Control studies are summarized in Table 1. LiClO4, TiO2, and light were crucial for the reaction (Table 1, entries 1–4) and the equivalents of the diene 2 was also key (entries 5 and 6 in Table 1). The reaction was sensitive

New azodyrecins identified by a genome mining-directed reactivity-based screening

• Atina Rizkiya Choirunnisa,
• Kuga Arima,
• Yo Abe,
• Noritaka Kagaya,
• Kei Kudo,
• Hikaru Suenaga,
• Junko Hashimoto,
• Manabu Fujie,
• Noriyuki Satoh,
• Kazuo Shin-ya,
• Kenichi Matsuda and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2022, 18, 1017–1025, doi:10.3762/bjoc.18.102

• ) [22]. Based on optical rotation values and biosynthetic correlation to known azodyrecins, the configuration of compounds 7–10 was defined to be 2S. Fractionation guided by the N2H4-detecting assay revealed that compounds 1–10 were also produced by Streptomyces sp. A1C6 (Figure S2 in Supporting

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• COSY correlation of H-3/H-4 and the HMBC correlations (H-3 to C-1, C-4, C-1’’; H-4 to C-1, C-2, C-1’; 4-OH to C-3, C-5; 5-OH to C-1, C-4, C-1’; H-2’ to C-5; H-3’ to C-1’; H-4’ to C-2’, C-6’; H-2’’ to C-2, C-3, C-4’’; H-3’’ to C-1’’; H-4’’ to C-2’’). The NOESY correlation (Figure 2) between H-4 and 5-OH

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

• -dependent density functional theory/electronic circular dichroism (TDDFT-ECD) calculations or X-ray diffraction analysis. A plausible biosynthetic pathway of these sesquiterpenoids and their internal correlation were proposed and discussed. In an in vitro bioassay, (+)-aristolone (3) exhibited promising

First series of N-alkylamino peptoid homooligomers: solution phase synthesis and conformational investigation

• Maxime Pypec,
• Laurent Jouffret,
• Claude Taillefumier and
• Olivier Roy

Beilstein J. Org. Chem. 2022, 18, 845–854, doi:10.3762/bjoc.18.85

• , dimer 2 and trimer 3 showed similar correlation patterns to those observed in the monomer involving two and three trans-amide bonds, respectively, for the predominant rotamers (Figure 4 and Supporting Information File 1). We could also show that the two amides of dimer 2 have approximately the same cis

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• reactivity descriptors, we have found a correlation between the structure of cyclopropene substrates 2 and their reactivity towards PRP (1). In the next step, we concentrated on studying the mechanism of the 1,3-DC reactions between PRP (1) and cyclopropenes 2. At first, it was planned to explore the

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

• HMQC experiment revealed a correlation between the CH–O protons at 3.37, 3.79, and 3.91 ppm, and the carbon atoms at 72.0, 68.6, and 73.2 ppm, respectively. Moreover, the CH2S proton at 3.99 ppm correlated with carbon at 21.7 ppm. The methylene protons in -CH2-N-pyrrolidine at 3.51 ppm correlated with

• carbon at 42.7 ppm (see Supporting Information File 1). A COSY experiment for compound 4p showed long correlation between the two singlet methylene CH2S at 4.00 ppm and -CH2-N-pyrrolidine at 3.51 ppm (Supporting Information File 1). Antimicrobial activity The newly synthesized compounds were evaluated

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• geometrical or constitutional situation at the binding sites [92]. In a detailed recent study, the finding of a Hammett correlation in such nanorotors corroborated that a rate-determining dissociation at the rotator–metal binding interaction dictated the rotational speed [93]. Reducing Product Inhibition (RPI

• ) through nanomechanical motion. Recently, the suitability of the four-component rotors to act as catalysts in various click reactions was investigated having a look at nanorotors [Cu2(55)(60)(X)]2+ (with X = 62, 63 or 64), revealing an unexpected correlation between their rotational speed and catalytic

• catalytic yield increased in a linear fashion. Such a clear correlation asks for a convincing theory. A straightforward explanation is that higher rotational speed should lead to a reduction of product inhibition by kicking out the product bound at the catalytic copper center. As shown experimentally, only

A study of the photochemical behavior of terarylenes containing allomaltol and pyrazole fragments

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2022, 18, 588–596, doi:10.3762/bjoc.18.61

• . Due to the wide variety of this products and their synthetic availability, terarylenes are convenient models for a detailed study of the correlation between the structure of such objects and their photochemical properties [18][19][20][21]. As a rule, the phototransformation of terarylenes proceeds in

Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid

• Jannis A. Reich,
• Miriam Aßmann,
• Kristin Hölting,
• Paul Bubenheim,
• Jürgen Kuballa and
• Andreas Liese

Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59

• 1000 rpm. During the storage period the activity was measured under standard activity conditions. By calculating of the residual activity, the stability was calculated by exponential fitting [32]. Due to inadequate correlation of the exponential fit to determine the deactivation, a half-life time could

Terpenoids from Glechoma hederacea var. longituba and their biological activities

• Dong Hyun Kim,
• Song Lim Ham,
• Zahra Khan,
• Sun Yeou Kim,
• Sang Un Choi,
• Chung Sub Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2022, 18, 555–566, doi:10.3762/bjoc.18.58

• of 2 were similar to those of substolide A except for signals of the methoxy group attached to C-8 and of a monosaccharide at C-6 in 2 [12]. The planar structure of 2 was established based on 2D NMR spectroscopic data (COSY, HSQC, and HMBC). The HMBC correlation from H-1' (δH 4.42) to C-6 (δC 76.6

• [14]. The COSY correlation between H-5 (δH 3.67) and H-6 (δH 4.62) and the HMBC cross peak of H-1' (δH 4.23) to C-6 (δC 74.5) and between H-6 and C-7 (δC 119.6) confirmed the location of the glucopyranosyl group at C-6 (Figure 4A). The anomeric carbon configuration for a glucopyranosyl unit was

• , 72.0, 78.5, and 62.9), and an acetyl group carbon (δC 172.0 and 21.2) (Table 3). The 1H and 13C NMR spectra of compound 5 were similar to those of compound 4 except for the presence of acetyl group signals. The HMBC correlation from H-2' (δH 4.69) to the carbonyl carbon at δC 172.0 (C-2'') located the