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

• subunit. View of the molecular structure of compound 10aa with atom labeling. Displacement ellipsoids are drawn at the 30% probability level. The intramolecular hydrogen bond N15–H15···O13 is shown as dashed line. The PES of reaction for the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-dione 10ab

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

• ). Increasing the amount of alkyne 4 increases the probability of the alkyne being coordinated in contrast to the tetrazole, which leads to launching of the CuAAC cycle. The probability of coordination on the tetrazole should also be indirectly impacted by this. However, the imidazole formation is only slightly

• ',1'-c]quinoxaline (24) and conversion to triazoloimidazoquinoxalines (TIQs): 2.5 equiv hexyne, 10 mol % (CuOTf)2·C6H6 (7), toluene, 100 °C, 4 h to 3 d. ORTEP diagram of triazoloimidazoquinoxaline 25b with the thermal ellipsoids shown at 50% probability. Synthesis of rhenium tricarbonyl complexes 27a

• –d and ORTEP diagrams of the resulting molecular structures with the thermal ellipsoids shown at 50% probability. Synthesis of rhenium tricarbonyl complex 29 and ORTEP diagram of the resulting molecular structure with the thermal ellipsoids shown at 50% probability. Synthesis of a TIQ rhenium complex

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

• % probability level). Experimental and calculated ECD curves of (+)-1. 1H-1H COSY, key HMBC correlations, and NOESY correlations of compound 5. Experimental ECD curves of compounds (+)-4, (−)-4 (top), (+)-5, and (−)-5 (bottom). Compound 3 reduced the mRNA levels of TNF-α (left) and CCL2 (right) in LPS

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

• and DH-1–3. Molecular structures and side view for DH-1 and DH-2. A and B are molecular structures for DH-1 and DH-2. C and D are side views for DH-1 and DH-2. Carbon, sulfur, selenium, and silicon atoms are depicted with thermal ellipsoids set at the 30% probability level and all hydrogen atoms are

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

• and 2b (Figure 3B). The DP4+ statistical analysis supported the structural equivalence of 2 to 2a (α-configuration at C-8) with 93% probability (Figure 3B). The absolute configuration of 2 was implied based on a comparison of the calculated ECD spectra of 2a and experimental ECD spectra of 2 (Figure

• + probability using an Excel sheet [25]. Chemical structures of compounds 1–9. Structure elucidation of 1. (A) Key COSY, HMBC, and NOE correlations of 1. (B) Comparison of calculated ECD data of 1a and experimental ECD spectrum of 1. Structure elucidation of 2. (A) Key COSY, HMBC, and NOE correlations of 2. (B

Comparative study of thermally activated delayed fluorescent properties of donor–acceptor and donor–acceptor–donor architectures based on phenoxazine and dibenzo[a,j]phenazine

• Saika Izumi,
• Prasannamani Govindharaj,
• Anna Drewniak,
• Paola Zimmermann Crocomo,
• Satoshi Minakata,
• Leonardo Evaristo de Sousa,
• Piotr de Silva,
• Przemyslaw Data and
• Youhei Takeda

Beilstein J. Org. Chem. 2022, 18, 459–468, doi:10.3762/bjoc.18.48

• each transition (detailed in Supporting Information File 1, Table S8 and Table S9). In the case of the D–A compound 1, the singlet population is expected to split mostly into T1 (33%) and T2 states (42%), with about 2% probability expected for prompt fluorescence. On the other hand, for the D–A–D

• compound POZ-DBPHZ, transitions to T1 display 48% probability whereas fluorescence has around 4%. The remaining probabilities are mostly distributed between transfers to T2 and T3 with about 20% each. Transfers to higher lying triplet states may end up relaxing to the lowest triplet state by means of

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

• also shown. Thermal ellipsoids at rt were drawn at the 50% probability level. Atoms are represented with the usual colour code (C: black; N: blue; O: red; S: yellow; H: white). Substrate scope of the borylcopper-mediated homocoupling of oxindole-based N-tert-butanesulfinyl imines 1 (isolated yields in

Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography

• Kian Donnelly and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 232–239, doi:10.3762/bjoc.18.27

• batch mode to continuous flow mode. The use of an insoluble reagent (e.g. K2CO3) is generally problematic with continuous flow reactors, due to the high probability of blockages occurring within the reactor tubing. To overcome this, we opted to incorporate a packed bed reactor into the continuous flow

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

• /v, flow rate 1.0 mL/min, 254 nm, τminor = 13.0 min, τmajor = 13.9 min, 90% ee). HRMS (m/z): [M + Na]+ calcd for C17H17BrN2NaO4+, 415.0264; found, 415.0278. ORTEP diagram drawn with 30% ellipsoid probability for non-H atoms of the crystal structure of chiral compound 4a determined at 293 K. The

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

• -Dihydroindolo[3,2-d][1]benzazepin-6(5H)-one or paullone (A), 5,12-dihydroindolo[3,2-d][2]benzazepin-7(6H)-one (B), 7,8-dihydroindolo[2,3-d][1]benzazepin-6(5H)-one (C), and 5,8-dihydroindolo[2,3-d][2]benzazepin-7(6H)-one (D). ORTEP view of 1a with thermal ellipsoids drawn at the 50% probability level. ORTEP view

• of 3a with thermal ellipsoids drawn at the 50% probability level. Investigated retrosynthetic pathways to scaffold C. Attempted synthesis of scaffold C by route (a). Attempted synthesis of C by route (b). Attempted synthesis of N-benzylated indole-2-acetic acid. Attempt to obtain open-chain precursor

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

• scaffold. Selected examples of bioactive spirobarbiturates. The screened organocatalysts. X-ray crystal structure of 3ae (displacement ellipsoids are drawn at the 50% probability level). Known strategies and conceptual advance of this contribution. Substrate scope of 2-isothiocyanato-1-indanones. The

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• higher probability of occurrence (17.8%). The non-helical conformation c3 of P5 trans (7.5%) is slightly less populated than the corresponding c2 of P5 cis. The macrocycle of both isomers is found to be rather flexible, forming well-separated conformational clusters in the three-dimensional space of PC1

• active conformation of axin’s binding domain (superimposed in transparent grey). P6 also forms a similar α-helix with a fairly high probability (14.7%). However, the main conformation of P6 (26.2%) is found to be formed by two β-sheets linked by a turn at the middle of the sequence. The second and third

• acids with a cumulative probability of 33.1, 37.5, and 45.2%, respectively. Noteworthy, these percentages are not re-weighted and are, therefore, somewhat biased by the aMD protocol. Yet, trends should be qualitatively captured by the analysis, which correlates fairly well with the experimental results

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

• reaction, which mainly include styrene and p-toluenesulfonic acid. As a result, when the reaction is performed at large scales, there is a high probability that the product can be purified by methods such as partition, precipitation and crystallization. The major advantage of using a base-labile protecting

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

• the present study. ORTEP diagram of the crystal structure of (E)-2-(((2-phenyl-4-(trifluoromethyl)quinolin-6-yl)imino)methyl)phenol (3ba, CCDC 2036933). (a) Displacement ellipsoids are drawn at the 50% probability level, and circles with arbitrary radius represent the hydrogen atoms; (b) side view

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• -triazine derivatives. Molecular structures of compounds 12h (A) and 13c (B) representing both possible regioisomers of the alkylation reaction (displacement parameters are drawn at the 50% probability level). The X-ray data corroborate the obtained NMR data. Graphical overview about selected pyrazolo[1,2,3

Enantioselective PCCP Brønsted acid-catalyzed aminalization of aldehydes

• Martin Kamlar,
• Robert Reiberger,
• Martin Nigríni,
• Ivana Císařová and
• Jan Veselý

Beilstein J. Org. Chem. 2021, 17, 2433–2440, doi:10.3762/bjoc.17.160

• strategies employing chiral Brønsted acid catalysis. X-ray single-crystal structure of aminal 3l with the displacement ellipsoids drawn at the 30% probability level. The substrate scope of the aminalization reaction for different aldehydes. aAfter recrystallization; breaction run at 1 mmol scale. The

(Phenylamino)pyrimidine-1,2,3-triazole derivatives as analogs of imatinib: searching for novel compounds against chronic myeloid leukemia

• Luiz Claudio Ferreira Pimentel,
• Lucas Villas Boas Hoelz,
• Henayle Fernandes Canzian,
• Frederico Silva Castelo Branco,
• Andressa Paula de Oliveira,
• Vinicius Rangel Campos,
• Floriano Paes Silva Júnior,
• Rafael Ferreira Dantas,
• Jackson Antônio Lamounier Camargos Resende,
• Anna Claudia Cunha,
• Nubia Boechat and
• Mônica Macedo Bastos

Beilstein J. Org. Chem. 2021, 17, 2260–2269, doi:10.3762/bjoc.17.144

• 2b. Displacement ellipsoids are drawn at the 50% probability level. Screening of the triazole derivatives of imatinib 1a,b, and 2a–j at concentrations of 1 μM and 10 μM against the human K562 cell line. Bars represent the mean ± standard deviation. The standard used was IMT. Interaction maps of IMT

Breaking paracyclophane: the unexpected formation of non-symmetric disubstituted nitro[2.2]metaparacyclophanes

• Suraj Patel,
• Tyson N. Dais,
• Paul G. Plieger and
• Gareth J. Rowlands

Beilstein J. Org. Chem. 2021, 17, 1518–1526, doi:10.3762/bjoc.17.109

• –208 °C; Rf: 0.25 (30% EtOAc, 70% hexane). The common [2.2]cyclophanes. Crystal structure of 5. Ellipsoids are drawn at a 50% probability level [63][64][65][66]. Crystal structure of 6. Ellipsoids are drawn at a 50% probability level [63]. Crystal structure of 14. Ellipsoids are drawn at a 50

• % probability level [63]. Crystal structure of 15. Ellipsoids are drawn at a 50% probability level [63]. Possible origin of stereoselectivity. Nitration of [2.2]paracyclophane (1) and the synthesis of 4-hydroxy-5-nitro[2.2]metaparacyclophane (5) and the cyclohexadienone cyclophane 6 (average yield from more

A straightforward conversion of 1,4-quinones into polycyclic pyrazoles via [3 + 2]-cycloaddition with fluorinated nitrile imines

• Greta Utecht-Jarzyńska,
• Karolina Nagła,
• Grzegorz Mlostoń,
• Heinz Heimgartner,
• Marcin Palusiak and
• Marcin Jasiński

Beilstein J. Org. Chem. 2021, 17, 1509–1517, doi:10.3762/bjoc.17.108

• of 3-trifluoromethylpyrazole derivative 9d. The labeling scheme of the asymmetric unit is shown. Anisotropic displacement parameters of nonhydrogen atoms are drawn as ellipsoids with a 50% probability level. N atoms in blue, O atoms in red, C atoms in grey, H atoms as small white spheres. Structure

Free-radical cyclization approach to polyheterocycles containing pyrrole and pyridine rings

• Ivan P. Mosiagin,
• Olesya A. Tomashenko,
• Dar’ya V. Spiridonova,
• Mikhail S. Novikov,
• Sergey P. Tunik and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2021, 17, 1490–1498, doi:10.3762/bjoc.17.105

• parameters are drawn at 50% probability level. Molecular structure of compound 17a, displacement parameters are drawn at 50% probability level. Retrosynthetic analysis of heterocycles A and B. Free-radical cyclization of N-protected and N-unprotected pyrroles 1a and 2. Synthesis of 2H-pyrido[2,1-a]pyrrolo

Cascade intramolecular Prins/Friedel–Crafts cyclization for the synthesis of 4-aryltetralin-2-ols and 5-aryltetrahydro-5H-benzo[7]annulen-7-ols

• Jie Zheng,
• Shuyu Meng and
• Quanrui Wang

Beilstein J. Org. Chem. 2021, 17, 1481–1489, doi:10.3762/bjoc.17.104

• stereostructures of compound cis-14aa and trans-14aa. Crystal structure of the tosylate 21. The displacement ellipsoids are drawn at the 30% probability level. Reported strategies for the synthesis of tetralin-2-ol ring systems. Designed cascade reactions to 4-substituted tetralin-2-ols. The documented synthesis

Co-crystallization of an organic solid and a tetraaryladamantane at room temperature

• Fabian Rami,
• Jan Nowak,
• Felix Krupp,
• Wolfgang Frey and
• Clemens Richert

Beilstein J. Org. Chem. 2021, 17, 1476–1480, doi:10.3762/bjoc.17.103

• to the rapid thermal crystallization with a liquid guest alone, is not in conflict with the notion that co-crystallization suffers from processes that inhibit nucleation or crystal growth. Co-crystals are still expected to form slowly because of the low probability of molecules arriving at the

• have thus far evaded crystallization by themselves. Structure of TDA and TEO, the crystallization hosts used for co-crystallization. Details of the X-ray crystal structures obtained, shown as ORTEP plots at 50% probability, with van der Waals radii of the phenol molecules set to 60%. a) Asymmetric unit

Synthetic accesses to biguanide compounds

• Oleksandr Grytsai,
• Cyril Ronco and
• Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• introduces primary amines for 1,3-dipolar cycloaddition which is less explored due to the probability of competitive Strecker degradation over decarboxylation of azomethine ylides. The protocol reveals the efficiency of MW assisted reaction with reduced reaction time from 18 h to 12 min and enhanced the

α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams

• Mikhail K. Klychnikov,
• Radek Pohl,
• Ivana Císařová and
• Ullrich Jahn

Beilstein J. Org. Chem. 2021, 17, 688–704, doi:10.3762/bjoc.17.58

• /EtOAc 10:1 to 1:1) to give keto lactam 13. Selected alkaloids containing the pyrrolidone motif. X-ray crystal structure of the major (2R,4S)-alkoxyamine hydrochloride derived from 9j. Displacement ellipsoids at 30% probability level and a disordered CHCl3 solvent molecule is not shown for clarity. X-ray

• crystal structure of the minor cis-diastereomers of the keto lactam 13j (left) and the hydroxy lactam 12k (right). Displacement ellipsoids are drawn at the 30% probability level. A) Classical γ-lactam synthesis by atom transfer radical cyclizations; B) previously developed tandem epoxide opening/Brook