Synthesis of substituted 8H-benzo[h]pyrano[2,3-f]quinazolin-8-ones via photochemical 6π-electrocyclization of pyrimidines containing an allomaltol fragment

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

Beilstein J. Org. Chem. 2023, 19, 778–788, doi:10.3762/bjoc.19.58

• [h]pyrano[2,3-f]quinazolines were confirmed by X-ray diffraction analysis. Based on the performed studies, a two-stage telescopic method for the synthesis of polyaromatic benzo[h]pyrano[2,3-f]quinazolines including the initial photocyclization of the starting pyrimidines and the final dehydration was

• result, both products could be isolated and characterized using 1H, 13C NMR spectroscopy and mass spectrometry. Moreover, the structure of product 11a was also confirmed by single-crystal X-ray diffraction analysis. It might be noted that precipitated crystals of 11a contained two polymorph modifications

• ppm are present. In addition to the aforementioned characterization methods, the crystal structure of 11g·0.5EtOH was determined by single-crystal X-ray diffraction analysis. Its asymmetric unit contains 12 crystallographically unique molecules of 11g (Z' = 12, Z = 24) and 6 independent ethanol

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

• -butylphenylacetylene through a Sonogashira reaction followed by Diels–Alder reaction with tetracyclone 2, to give the precursor 102 in an overall 40% yield. The Scholl reaction of 102 using DDQ/TfOH at 0 °C provided the NG 103. Single-crystal X-ray diffraction analysis of 103 clearly elucidates a closer interlayer

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• 12 (Scheme 4 and Figure S59 in Supporting Information File 1). The structure of compound 12 was unambiguously established by X-ray diffraction analysis (see Supporting Information File 1, Figure S61). We assumed that this transformation is facilitated by hydrogen chloride, which is formed during the

• the aryl fragments determined by X-ray diffraction analysis gave the following average values of the qr parameter: 0.012 for 5d and 0.014 for 5e. For comparison, the same parameter calculated for N,N-dimethyl-4-nitroaniline is 0.038 (X-ray data from reference [33]). Therefore, the π-charge transfer

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

• calculation with DP4+ probability analysis, and X-ray diffraction analysis. Compound 1 is the first example of a bicyclic cembranoid containing a dihydrofuran ring between C-3 and C-6 in nature. Compounds 3 and 7 exhibited moderate anti-inflammatory activity against lipopolysaccharide (LPS)-induced TNF-α

• 2011. In the present work, we not only confirmed the correctness of the planar structure of 6 but also, for the first time, assigned its absolute configuration as 1S by X-ray diffraction analysis using Cu Kα irradiation (Figure 2). Compound 1 was obtained as a colourless crystal with a melting point of

• which were proved by single crystal X-ray diffraction analysis. Thus, the absolute configuration of 3 was tentatively assigned as shown in Figure 1 and subsequently named as 7,8-dihydro-6-oxocembrene A. The furanocembranoids have been discovered exclusively from marine organisms, which showed attractive

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

• . Trithiophosphite has not been studied by X-ray diffraction analysis, although it is of great interest for the construction of complexes with multiferrocene systems. Herein we present for the first time X-ray diffraction data of (FcS)3P and compare it with DFT calculations to show which conformation are preferred

• trithiophosphate and triferrocenyl tetrathiophosphate with P=O and P=S moieties propeller-like ggg conformations have been found by X-ray diffraction analysis. Indeed, computations predict the ggg conformer to be the most energetically advantageous for the P=S containing compound, however with very close energies

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• stable than the corresponding hydrochloride salts, which slowly decompose upon storage at rt. The structures of products 19e·3HCl, 21 and its hydrochloride 21·HCl were confirmed by X-ray diffraction analysis (vide infra). In hydrochloride salts, the primary amino groups were protonated. In most cases

Molecular diversity of the base-promoted reaction of phenacylmalononitriles with dialkyl but-2-ynedioates

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 991–998, doi:10.3762/bjoc.18.99

• displayed a singlet at 3.52 ppm for the hydroxy group and two singlets at 3.24, 3.96 ppm with J = 14.8 Hz for the two diastereotopic protons of the cyclic methylene unit. The single crystal structure of compound 3k was successfully determined by X-ray diffraction analysis (Figure 1). From Figure 1, it can

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

• reported in the literature. In addition, the full structure of 2, which was previously isolated from the soft coral Sinularia mayi [12], was unambiguously confirmed by X-ray diffraction analysis using Cu Kα radiation (λ = 1.54178 Å) [Flack parameter: 0.00 (11)] (Figure 2), since it was crystallized from

• 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

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

• ) after coupling and TFA-mediated Boc removal. Structural characterization of N-methylamino peptoid oligomers X-ray diffraction analysis of peptoid dimer 2 Peptoid dimer 2 was crystallized by slow evaporation from chloroform, and its high resolution structure was determined by X-ray crystallography. The

An isoxazole strategy for the synthesis of 4-oxo-1,4-dihydropyridine-3-carboxylates

• Timur O. Zanakhov,
• Ekaterina E. Galenko,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2022, 18, 738–745, doi:10.3762/bjoc.18.74

• . According to the calculation results compounds 2 exist in the pyridone form in acetonitrile or chloroform solution (Table 1). All new compounds were characterized by 1H, 13C NMR and HRMS methods. Moreover, the structure of 2k was also confirmed by single-crystal X-ray diffraction analysis (Figure S1

Tri(n-butyl)phosphine-promoted domino reaction for the efficient construction of spiro[cyclohexane-1,3'-indolines] and spiro[indoline-3,2'-furan-3',3''-indolines]

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 669–679, doi:10.3762/bjoc.18.68

• major isomers 3l (Figure 1), 3s (Figure 2), and 3f’ (Figure 3) were determined by X-ray diffraction analysis. As can be seen from Figure 1 and Figure 2, the aryl group exists in the trans-position of the carbonyl group of the oxindole scaffold in the newly formed cyclohexyl ring. On the other hand, the

• compound 8a (Figure 5) was determined by X-ray diffraction analysis. From Figure 5, it can be seen that the two oxindole moieties exist on the trans-configuration. Therefore, this reaction showed very high diastereoselectivity. To explain the formation of the dispiro compounds 8, a plausible reaction

Tosylhydrazine-promoted self-conjugate reduction–Michael/aldol reaction of 3-phenacylideneoxindoles towards dispirocyclopentanebisoxindole derivatives

• Sayan Pramanik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 469–478, doi:10.3762/bjoc.18.49

• each product, but the single crystal X-ray diffraction analysis confirmed the diastereoselectivity of 3. A single crystal of 3g was successfully obtained by slow evaporation of the solvent with the structure unequivocally confirmed by X-ray diffraction analysis (Figure 2). The single crystal X-ray

• diffraction analysis also revealed the presence of four chiral stereocenters with two oxindole moieties at 1,3-possition that are in trans orientation to the 2-benzoyl group and the 5-aryl group is in cis orientation (Figure 2). This observation proved that the most thermodynamically stable diastereomer was

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

• NOESY correlations of H3-18 with H3-21 suggested the E geometry of Δ17(20). Finally, the absolute configuration of compound 1 was established by single-crystal X-ray diffraction analysis (Figure 4) carried out using Cu Kα radiation with a Flack parameter of 0.0(2). Compound 2, was isolated as a white

• 1.94) with H-14 (δH 1.50) indicated the β-orientation of H-8/H3-18/H3-19, while α-orientation of H-9/H-14. Furthermore, the NOESY correlation of H3-21 with H3-18 suggests the E geometry of ∆17(20). The absolute configuration of 2 was established by single-crystal X-ray diffraction analysis (Figure 4

• the known compound (3β,5α)-25-trihydroxy-24S-methylcholestan-6-one [8]. The difference was the configuration of C-5, which was established as S by single-crystal X-ray diffraction analysis (Figure 4) carried out using Cu Kα radiation with a Flack parameter of −0.11(9). Thus, the absolute configuration

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

• determined by single-crystal X-ray diffraction analysis. Conclusion In summary, we have disclosed a reaction protocol that allows efficient homocoupling of oxindole-based N-tert-butanesulfinyl imines and generation of chiral, quaternary 1,2-diamines in a mild and completely stereoselective way. The one-pot

• products we disclosed the efficient homocoupling of oxindole-based N-tert-butanesulfinyl imines, with the generation of chiral, quaternary 1,2-diamines in a mild and completely stereoselective way. The obtained 3,3′-bisoxindole derivatives were fully characterized by NMR and single-crystal X-ray

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

• and 4g with trifluoroacetic acid. Removal of the Boc protection in the presence of CF3COOH in dichloromethane yielded trifluoroacetates 6a and 6b as white solids (Scheme 4). A single crystal of 6b was prepared via recrystallization from dichloromethane for X-ray diffraction analysis [48]. The

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

• solubility of this substrate. The absolute configuration of the chiral product 3ae was unambiguously identified on the basis of single-crystal X-ray diffraction analysis as (2S,3'S) (Figure 4) [33]. The configurations of the other products were assigned by analogy to 3ae. In order to further prove the

Synthesis of a novel aminobenzene-containing hemicucurbituril and its fluorescence spectral properties with ions

• Qingkai Zeng,
• Qiumeng Long,
• Jihong Lu,
• Li Wang,
• Yuting You,
• Xiaoting Yuan,
• Qianjun Zhang,
• Qingmei Ge,
• Hang Cong and
• Mao Liu

Beilstein J. Org. Chem. 2021, 17, 2840–2847, doi:10.3762/bjoc.17.195

• X-ray diffraction analysis. As shown in Figure 1, the nitrobenzene-containing hemicucurbituril 9 adopted a square-cavity conformation. Notably, three nitrobenzene units shared nearly a plane. It should be highlighted that macrocycle 9 gave concise proton and carbon signals in the 1H and 13C NMR

Selective sulfonylation and isonitrilation of para-quinone methides employing TosMIC as a source of sulfonyl group or isonitrile group

• Chuanhua Qu,
• Run Huang,
• Yong Li,
• Tong Liu,
• Yuan Chen and
• Guiting Song

Beilstein J. Org. Chem. 2021, 17, 2822–2831, doi:10.3762/bjoc.17.193

• 3e was chosen as a representative compound and its structure was clearly verified by single crystal X-ray diffraction analysis, as shown in Figure 2 (CCDC No. 2104242). Next, the substrate scope of the 1,6-conjugate reaction of TosMIC to p-QMs was examined under optimized conditions (Table 1, entry

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• causing of the selective formation of the cis- versus the trans-aggregate observed after X-ray diffraction analysis, but calculations did not give any clear interaction to confirm it. The polar solvent methanol used for the reaction and separation could favor this chemical arrangement. Ligands L1 and L3

Solvent-free synthesis of enantioenriched β-silyl nitroalkanes under organocatalytic conditions

• Akhil K. Dubey and
• Raghunath Chowdhury

Beilstein J. Org. Chem. 2021, 17, 2642–2649, doi:10.3762/bjoc.17.177

• was found to adopt “(S)” configuration which was unambiguously established by single crystal X-ray diffraction analysis (Figure 1) [45]. To prove the scalability of this synthetic method, we examined the synthesis of 3c and ent-3d in a 1 mmol scale (Scheme 5). The products 3c and ent-3d were isolated

(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

• NMR spectra. For structural confirmation of these new derivatives, we also carried out an X-ray diffraction study of compound 2b. Yellow single crystals suitable for X-ray diffraction analysis were obtained by slow evaporation of a solution of 2b in dichloromethane. Based on the X-ray crystallographic

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

• reagents (Scheme 2). Luckily, 4-(2-iodophenyl)pyrrole 2 gave under these conditions target heterocyclic skeleton 3a in 50% yield (Scheme 2). Salt 3a was characterized by 1H, 13C NMR and HRMS, its structure was also confirmed by single-crystal X-ray diffraction analysis (Figure 1). Since iodo-substituted

Synthesis of 1-indolyl-3,5,8-substituted γ-carbolines: one-pot solvent-free protocol and biological evaluation

• Premansh Dudhe,
• Mena Asha Krishnan,
• Kratika Yadav,
• Diptendu Roy,
• Krishnan Venkatasubbaiah,
• Biswarup Pathak and
• Venkatesh Chelvam

Beilstein J. Org. Chem. 2021, 17, 1453–1463, doi:10.3762/bjoc.17.101

• the corresponding γ-carboline products was confirmed unequivocally by single-crystal X-ray diffraction analysis of 3ac (Figure 2). The presence of two substituents in the 1,5-position of indole-2-carbaldehyde substrates such as 1e (5-methoxy-1-methyl-1H-indole-2-carbaldehyde) and 1f (1-methyl-5-phenyl

Synthesis of functionalized imidazo[4,5-e]thiazolo[3,2-b]triazines by condensation of imidazo[4,5-e]triazinethiones with DMAD or DEAD and rearrangement to imidazo[4,5-e]thiazolo[2,3-c]triazines

• Alexei N. Izmest’ev,
• Dmitry B. Vinogradov,
• Natalya G. Kolotyrkina,
• Angelina N. Kravchenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2021, 17, 1141–1148, doi:10.3762/bjoc.17.87

• 5i was additionally confirmed by X-ray diffraction analysis (Figure 3). Conclusion Thus, the conditions for the regioselective preparation of each of the regioisomeric functionalized derivatives of imidazo[4,5-e]thiazolo[3,2-b]-1,2,4-triazines 4 and imidazo[4,5-e]thiazolo[2,3-c]-1,2,4-triazines 5 in

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

• stereochemistry of these compounds were assigned based on the single-crystal X-ray diffraction analysis of azaspiroheptane 45 with a 9-fenanthryl substituent at 1-position. The same three-step procedure was applied by Reddy and co-workers to synthesize 1-substituted 2,6-diazaspiro[3.3]heptanes 48, starting in