Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• DFT studies to elucidate the mechanism of CO2 cycloaddition to aziridines using a metal-free protonated porphyrin macrocycle and found that the catalytic cycle started with simultaneous activation of both CO2 and N-butyl-2-phenylaziridine (69b). The main strategies used in metal-free porphyrin

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

Manganese-catalyzed C–C and C–N bond formation with alcohols via borrowing hydrogen or hydrogen auto-transfer

• Mohd Farhan Ansari,
• Atul Kumar Maurya,
• Abhishek Kumar and
• Saravanakumar Elangovan

Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98

• -membered rings were also formed only by changing the alcohols to hexane-1,6-diol under the same conditions as above, giving yields up to 80%. In addition, several ketones were investigated under these conditions with different diol systems, giving 55–80% yields of the cyclic products (Scheme 36). DFT

• studies showed that the hemilability and bifunctionality of the thiophene arm attached to the metal play an important role in this transformation for the dehydrogenation and hydrogenation steps. Later, the same complex was successfully used for the α-alkylation of ketones with secondary alcohols to

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• dinaphthooxanorcaradiene bisimide valence isomer obtained upon electron injection and not its neutral form, as shown by UV–vis absorption and DFT studies. The mechanism of the final release of oxygen still remains unclear. This example shows that a careful molecular design allows endowing chalcogen heteropines with

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• , electrophilic properties of atom C3 should be mainly explained by orbital factors, rather than charge ones. Summarizing the data obtained during the synthesis of indanones 3 (Scheme 5, Scheme 6 and Table 1), NMR, and DFT studies on intermediate cations (Table 2 and Table 3), one may propose plausible reaction

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• styrenes 64 using a Ni–Al bimetallic system and NHC ligand 65 through intermolecular hydroarylation with high levels of enantio- and regioselectivity in the alkylated products 66 (Scheme 13). Also, the authors performed DFT studies revealing the reaction mechanism and supported that the interaction of the

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• electrochemically induced oxidative modification of the amino acid side chain. Experimental and DFT studies showed that the additional tert-butyl group increases the dispersion interactions in the Ni coordination environment making the complexes more conformationally rigid and provides a higher level of

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• theory (DFT) studies suggested that the excellent stereoselectivities of the catenane are a direct result of the cooperative interaction of both phosphoric acid groups, enabled by the mechanical bond. Follow-up studies showed that such acid–acid interactions are also relevant for monophosphoric acid

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• studies and as a part of our interest in discovering new organic materials applications [61][62][63], we herein report the synthesis of new 2,4-bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridine derivatives. The investigation of their photophysical properties and theoretical DFT studies were achieved

• relative method using quinine sulfate [70]. Tetrahydroacridine derivative 4g containing an electron-donating methoxy substituent gave the highest fluorescence intensity as shown in Figure 3 and a quantum yield of 20%. DFT studies The arylethynyl substituents showed an impact on the absorption and emission

Prins cyclization-mediated stereoselective synthesis of tetrahydropyrans and dihydropyrans: an inspection of twenty years

• Asha Budakoti,
• Pradip Kumar Mondal,
• Prachi Verma and
• Jagadish Khamrai

Beilstein J. Org. Chem. 2021, 17, 932–963, doi:10.3762/bjoc.17.77

• [107]. As reported previously by Feng et al. [106], two mechanistic pathways via the classical oxocarbenium route and [2 + 2]-cycloaddition were considered for DFT calculations. Experimental and DFT studies suggested the preference of a classical oxocarbenium route over the [2 + 2]-pathway for those

Mesoionic tetrazolium-5-aminides: Synthesis, molecular and crystal structures, UV–vis spectra, and DFT calculations

• Vladislav A. Budevich,
• Sergei V. Voitekhovich,
• Alexander V. Zuraev,
• Vadim E. Matulis,
• Vitaly E. Matulis,
• Alexander S. Lyakhov,
• Ludmila S. Ivashkevich and
• Oleg A. Ivashkevich

Beilstein J. Org. Chem. 2021, 17, 385–395, doi:10.3762/bjoc.17.34

• structures are known [17][28]. Thus, the information on tetrazole-5-aminides is very limited and fragmentary. In the present work, we try to fill this gap by carrying out experimental (synthesis, X-ray, UV–vis) and theoretical density functional theory (DFT) studies of some selected 1,3-dialkyltetrazolium-5

A review of the total syntheses of triptolide

• Xiang Zhang,
• Zaozao Xiao and
• Hongtao Xu

Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194

• -endo-trig cyclization of 2-alkenyl-1,3-dithiolanes to access trans-decalins (Figure 2, route K) [78]. Density functional theory calculation (DFT) studies indicated that the 2-alkenyl-1,3-dithiolane moiety acts as a latent initiator, which triggers the cationic 6-endo-trig cyclization in the presence of

Reactions of 2-carbonyl- and 2-hydroxy(or methoxy)alkyl-substituted benzimidazoles with arenes in the superacid CF₃SO₃H. NMR and DFT studies of dicationic electrophilic species

• Dmitry S. Ryabukhin,
• Alexey N. Turdakov,
• Natalia S. Soldatova,
• Mikhail O. Kompanets,
• Alexander Yu. Ivanov,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2019, 15, 1962–1973, doi:10.3762/bjoc.15.191

Different reactivity of phosphorylallenes under the action of Brønsted or Lewis acids: a crucial role of involvement of the P=O group in intra- or intermolecular interactions at the formation of cationic intermediates

• Stanislav V. Lozovskiy,
• Alexander Yu. Ivanov and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2019, 15, 1491–1504, doi:10.3762/bjoc.15.151

• intermolecular hydroarylation of allenes bearing electron-withdrawing substituents. Plausible reaction mechanisms have been proposed on the basis of the investigated reactions, and NMR analysis and DFT studies of the intermediate cationic species. Keywords: aluminum chloride; cation; intermediate

Design of a double-decker coordination cage revisited to make new cages and exemplify ligand isomerism

• Sagarika Samantray,
• Sreenivasulu Bandi and
• Dillip K. Chand

Beilstein J. Org. Chem. 2019, 15, 1129–1140, doi:10.3762/bjoc.15.109

• were found to be in agreement. DFT studies of the complexes The energy-minimized structures of [Pd(tmeda)(L1)]2+, [Pd3(tmeda)3(L1)2]6+, [Pd(L1)2]2+, and [(NO3)2@Pd3(L1)4]4+ are shown in Figure 4 (see Supporting Information File 1 for details). Geometry optimization and calculation of frequencies were

Calixazulenes: azulene-based calixarene analogues – an overview and recent supramolecular complexation studies

• Paris E. Georghiou,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Hidetaka Nishimura,
• Jaehyun Lee,
• Atsushi Wakamiya and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2018, 14, 2488–2494, doi:10.3762/bjoc.14.225

• a chloroform solution-state complexation binding study with Lash and Colby’s calix[4]azulene 3 using a series of tetraalkylammonium halides and tetrafluoroborate salts [20]. This study was also supplemented by DFT studies to support the trends observed in the experimentally-derived binding constants

A challenging redox neutral Cp*Co(III)-catalysed alkylation of acetanilides with 3-buten-2-one: synthesis and key insights into the mechanism through DFT calculations

• Andrew Kenny,
• Alba Pisarello,
• Arron Bird,
• Paula G. Chirila,
• Alex Hamilton and
• Christopher J. Whiteoak

Beilstein J. Org. Chem. 2018, 14, 2366–2374, doi:10.3762/bjoc.14.212

• procedure provides a wide substrate scope in terms of substituted acetanilides, although the optimised conditions were found to be more forcing than those for the corresponding benzamide substrates. Interestingly, density functional theory (DFT) studies reveal that the major impediment in the mechanism is

• not the C–H activation step, but instead and unexpectedly, effective competition with more stable compounds (resting states) not involved in the catalytic cycle. Keywords: acetanilides; alkylation; C–H activation; cobalt catalysis; DFT studies; Introduction Controlled functionalisation of ubiquitous

• , the acetanilide containing two aromatic moieties (1q) was subjected to the optimised reaction conditions (Scheme 4). The DFT studies suggested that selectivity should be observed between the two aromatic rings, in favour of the benzamide-type C–H functionalisation. In agreement with this proposal the

Stereochemical outcomes of C–F activation reactions of benzyl fluoride

• Neil S. Keddie,
• Pier Alexandre Champagne,
• Justine Desroches,
• Jean-François Paquin and
• David O'Hagan

Beilstein J. Org. Chem. 2018, 14, 106–113, doi:10.3762/bjoc.14.6

• fluoride substrates (Figure 1), producing the corresponding substituted products in moderate to good yields. The water/isopropanol system was also shown to be amenable to phenolate and thiolate nucleophiles [3]. Previously, Paquin et al. undertook density functional theory (DFT) studies on the mechanism of

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• studied. The polymer, derived from dithienylated benzothiodiazole and fluorene, P1, exhibited a highest occupied molecular orbital (HOMO) energy level at −5.48 eV. Density functional theory (DFT) studies as well as experimental measurements suggested that upon substitution of the acceptor with fluorine

Spectral and DFT studies of anion bound organic receptors: Time dependent studies and logic gate applications

• Srikala Pangannaya,
• Neethu Padinchare Purayil,
• Shweta Dabhi,
• Venu Mankad,
• Prafulla K. Jha,
• Satyam Shinde and
• Darshak R. Trivedi

Beilstein J. Org. Chem. 2017, 13, 222–238, doi:10.3762/bjoc.13.25

• output, the signaling unit has been linked to a conjugated system possessing a hydroxy functionality which acts as binding site for anions. UV–vis, 1H NMR titration studies along with DFT studies of the receptors R1 and R2 would help to arrive at the binding mechanism. The presence of heteroatoms in the

Synthesis of spiro[isoindole-1,5’-isoxazolidin]-3(2H)-ones as potential inhibitors of the MDM2-p53 interaction

• Salvatore V. Giofrè,
• Santa Cirmi,
• Raffaella Mancuso,
• Francesco Nicolò,
• Giuseppe Lanza,
• Laura Legnani,
• Agata Campisi,
• Maria A. Chiacchio,
• Michele Navarra,
• Bartolo Gabriele and
• Roberto Romeo

Beilstein J. Org. Chem. 2016, 12, 2793–2807, doi:10.3762/bjoc.12.278

• be linked to the inhibition of the protein–protein p53-MDM2 interaction. Docking measurements support the biological data. Keywords: antitumor agents; DFT studies; 1,3-dipolar cycloaddition; docking studies; spiro-compounds; Introduction The p53 tumor suppressor protein is a transcriptional factor

On the mechanism of imine elimination from Fischer tungsten carbene complexes

• Philipp Veit,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

• spectroscopy. Accordingly, W(CO)5(E-2) is a suitable candidate to investigate the imine formation from NH carbene complexes in a simple one-component system under relatively mild conditions and, importantly, in the absence of a base. DFT studies on the formation of imine E-3 from W(CO)5(E-2) Three conceivable

Conjugate addition–enantioselective protonation reactions

• James P. Phelan and
• Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

• was observed (86.5:13.5 to 89:11 er). Luo and Cheng also explored the mechanism of the Friedel–Crafts addition of indole to α-substituted vinyl ketones [52][53]. Based on DFT studies, the authors proposed that the stereoselectivity of the reaction was under Curtin–Hammett control (Scheme 28). During

Recent advances in C(sp³)–H bond functionalization via metal–carbene insertions

• Bo Wang,
• Di Qiu,
• Yan Zhang and
• Jianbo Wang

Beilstein J. Org. Chem. 2016, 12, 796–804, doi:10.3762/bjoc.12.78

• metal center to the ligand and to carbon dioxide was supported by experimental data and DFT studies. Such interaction increases the electrophilicity of the carbene moiety and thus lowers the activation energy for C–H bond insertion. Other ligands have also been explored for the metal–carbene C(sp3)–H

• except for methane (Scheme 11). The DFT studies suggested that formation of the silver carbene complex was the rate-determining step for alkane substrates such as ethane and propane. As for methane, the overall rate-determining step was carbene insertion into the C–H bond, attributed to the inertness of

Gold-catalyzed formation of pyrrolo- and indolo-oxazin-1-one derivatives: The key structure of some marine natural products

• Sultan Taskaya,
• Nurettin Menges and
• Metin Balci

Beilstein J. Org. Chem. 2015, 11, 897–905, doi:10.3762/bjoc.11.101

• -one derivatives. Some of the exo-cyclic double bonds underwent isomerization to endo-cyclic compounds upon treatment with TFA, while some did not. DFT studies supported our findings. Moreover, cyclization reactions in the presence of alcohol formed hemiacetal derivatives after gold-catalyzed cascade