Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• )benzenesulfonamides to give chiral azepane spirooxindoles with excellent stereoselectivity (reaction 2 in Scheme 1) [55][56]. Du and co-workers reported a DABCO-mediated [4 + 3] cycloaddition reaction between o-quinone methides and isatin-derived MBH carbonates to give functionalized benzo[b]oxepine derivatives in

Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

• Tzu-Yu Huang,
• Mario Djugovski,
• Sweta Adhikari,
• Destinee L. Manning and
• Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

• -withdrawing group, such as trifluoromethyl (4h), was obtained in 44% yield. When morpholine was replaced with piperidine (5a) or seven-membered azepane (5b) as a solvent, a decreased yield was observed (30–42%). The addition of piperidine offers an advantage in expanding the substrate scope to medicinal

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• azepane. A possible mechanism was suggested for this Lewis base catalysis system. Methanesulfonic acid (MsOH) activated reagent 14, which coordinated with the Lewis base (S)-E, to form complex I. Then, the transfer of the sulfenium ion to the alkene resulted in chiral thiiranium ion II. Capture of the

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

Pentannulation of N-heterocycles by a tandem gold-catalyzed [3,3]-rearrangement/Nazarov reaction of propargyl ester derivatives: a computational study on the crucial role of the nitrogen atom

• Giovanna Zanella,
• Martina Petrović,
• Dina Scarpi,
• Ernesto G. Occhiato and
• Enrique Gómez-Bengoa

Beilstein J. Org. Chem. 2020, 16, 3059–3068, doi:10.3762/bjoc.16.255

• of the accuracy of the computational method we have used for the comparison of the isomeric complexes I and V. Our previous experience in this area taught us that seven-membered azepane-derived enynyl acetates react faster than the corresponding piperidine analogues 1, prompting us to prepare enynyl

• cyclopenta-fused product 21 in 54% yield. Again, the reaction was very slow compared to the corresponding 2-substituted azepane derivative and provided many unidentified side products, reducing our interest in the process. Conclusion In summary, we computationally studied and experimentally verified the [3,3

Unexpected one-pot formation of the 1H-6a,8a-epiminotricyclopenta[a,c,e][8]annulene system from cyclopentanone, ammonia and dimethyl fumarate. Synthesis of highly strained polycyclic nitroxide and EPR study

• Sergey A. Dobrynin,
• Igor A. Kirilyuk,
• Yuri V. Gatilov,
• Andrey A. Kuzhelev,
• Olesya A. Krumkacheva,
• Matvey V. Fedin,
• Michael K. Bowman and
• Elena G. Bagryanskaya

Beilstein J. Org. Chem. 2019, 15, 2664–2670, doi:10.3762/bjoc.15.259

• molecules 1 and 6 is characterized by an elongation of the bonds C6A–C7 1.579(2), C8–C8A 1.573(2) Å in 1 and C3B–C6A 1.580(2), C8–C8A 1.573(2) Å in 6. The conformation of the azepane ring in 1 is close to a distorted boat with a kink at the C3A–N1 line, while in 6 the conformation of this ring is close to a

A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues

• Arno Verlee,
• Thomas Heugebaert,
• Tom van der Meer,
• Pavel I. Kerchev,
• Frank Van Breusegem and
• Christian V. Stevens

Beilstein J. Org. Chem. 2017, 13, 303–312, doi:10.3762/bjoc.13.33

• potential of a chemoselective synthesis as a continuous process. As bench mark, aniline and azepane were used as first and second reagent, respectively. After addition of the first reactant and completion of the reaction (followed by TLC) the second reactant was added. The chemoselectivity was determined by

• of sulfonylation. To improve the chemoselectivity when using secondary amines, an additional screening was performed with azepane and aniline as first and second reagent, respectively. Initially, we tried to increase the selectivity by decreasing the temperature. Unfortunately, the reaction mixtures

• performed, using azepane as the first and aniline as the second reactant. The concentrations used were 5 mM for F1 and F2 and 2.5 mM for F3. This leads to a final concentration of 1.25 mM. However, due to the increased flow rate, the second coupling step with aniline could not reach full conversion. Even by

Opportunities and challenges for direct C–H functionalization of piperazines

• Zhishi Ye,
• Kristen E. Gettys and
• Mingji Dai

Beilstein J. Org. Chem. 2016, 12, 702–715, doi:10.3762/bjoc.12.70

• hydroaminoalkylation for the synthesis of α-alkylated N-heterocycles from the corresponding heterocycles and alkenes [55]. Along with piperidine and azepane substrates, piperazine substrates of type 76 react smoothly with terminal olefins (78) in the presence of 10 mol % of catalyst 77 in toluene at 165 °C (Figure 14

A unified approach to the important protein kinase inhibitor balanol and a proposed analogue

• Tapan Saha,
• Ratnava Maitra and
• Shital K. Chattopadhyay

Beilstein J. Org. Chem. 2013, 9, 2910–2915, doi:10.3762/bjoc.9.327

• developed using an efficient fragment coupling protocol which proceeded in good overall yield. Keywords: azepane; balanol; Garner’s aldehyde; PKC inhibitor; ring-closing metathesis; Introduction Protein kinase C (PKC) is a family of phospholipid-dependent kinases that phosphorylate serine and threonine

• tetrahydroazepine derivative was confirmed by its selective conversion to the corresponding known azepane derivative 30 which displayed optical and 13C NMR data nearly overlapping with those reported by Nicolaou et al [17]. With the two key fragments 29 and 7 in hand, we next focused on their convergent combination

• possible synthesis of an azepane ring-modified balanol derivative along the projected pathway. To this end, dihydroxylation of the adduct 31 was next attempted. Pleasingly, the dihydroxylation of 31 proceeded smoothly; however, unfortunately to provide an inseparable mixture of the two possible

Stereoselectively fluorinated N-heterocycles: a brief survey

• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2013, 9, 2696–2708, doi:10.3762/bjoc.9.306

• rigidifying power of a fluorine substituent is strongly dependent on the other groups present. The non-fluorinated azepane 21 was found to exhibit extensive conformational disorder, and this was attributed to competing preferences for the OBn/N3 substituents to adopt pseudoequatorial positions and for the

• ). Fluorinated piperidines prefer the axial conformation, due to stabilising C–F…N+ interactions. Fluorination can rigidify a substituted azepane, but only if it acts in synergy with the other substituents: azepanes 21 and 22 are disordered, while azepane 23 has one dominant geometry in solution. The eight

α-Bromodiazoacetamides – a new class of diazo compounds for catalyst-free, ambient temperature intramolecular C–H insertion reactions

• Åsmund Kaupang and
• Tore Bonge-Hansen

Beilstein J. Org. Chem. 2013, 9, 1407–1413, doi:10.3762/bjoc.9.157

• Comparing with results obtained using dirhodium(II) catalysis, the α-H-analogue of the azepane derivative 5c was prepared in 67% yield by Doyle et al. from 3d [61]. They could also prepare the analogous azocane-derived α-H-β-lactam in 45% yield, accompanied by a 22% yield of the α-H-γ-lactam. Interestingly

A³-Coupling catalyzed by robust Au nanoparticles covalently bonded to HS-functionalized cellulose nanocrystalline films

• Jian-Lin Huang,
• Derek G. Gray and
• Chao-Jun Li

Beilstein J. Org. Chem. 2013, 9, 1388–1396, doi:10.3762/bjoc.9.155

• yields (Table 2, entries 1–8). However, long chain aldehydes had a lower activity, giving lower yields (Table 1, entries 9, 10). We also observed good to moderate yields when the cyclic dialkylamines such as pyrrolidine, morpholine and azepane were used (Table 2, entries 11–19). Catalyst recycling In

Selective copper(II) acetate and potassium iodide catalyzed oxidation of aminals to dihydroquinazoline and quinazolinone alkaloids

• Matthew T. Richers,
• Chenfei Zhao and
• Daniel Seidel

Beilstein J. Org. Chem. 2013, 9, 1194–1201, doi:10.3762/bjoc.9.135

• resulted in a lower yield than the corresponding pyrrolidine and azepane products (2 and 12, respectively). While differences in conformation may in part account for the observed differences in reactivity (X-ray crystal structures of aminals containing pyrrolidine and piperidine revealed that the

Cation affinity numbers of Lewis bases

• Christoph Lindner,
• Raman Tandon,
• Boris Maryasin,
• Evgeny Larionov and
• Hendrik Zipse

Beilstein J. Org. Chem. 2012, 8, 1406–1442, doi:10.3762/bjoc.8.163

• piperidine (139) and azepane (145). Aside from phosphanes with a direct phosphorus–nitrogen bond, a variety of phosphanes with nitrogen-containing substituents can be envisioned in which P- and N-centers are separated by at least one carbon atom. Results for these phosphanes are listed in Table 4. All MCA

Metathesis access to monocyclic iminocyclitol-based therapeutic agents

• Ileana Dragutan,
• Valerian Dragutan,
• Carmen Mitan,
• Hermanus C.M. Vosloo,
• Lionel Delaude and
• Albert Demonceau

Beilstein J. Org. Chem. 2011, 7, 699–716, doi:10.3762/bjoc.7.81

• for the role of olefin metathesis reactions (RCM, CM) as key transformations in the multistep syntheses of pyrrolidine-, piperidine- and azepane-based iminocyclitols, as important therapeutic agents against a range of common diseases and as tools for studying metabolic disorders. Considerable

• -tetrahydropyridine scaffold (72–88% yield, Scheme 24). Azepane-based iminocyclitols Iminocyclitols incorporating the azepane ring system are more flexible than the parent pyrrolidine and piperidine iminosugars, and they adopt quasi-flattened, low-energy conformations which can potentially lead to a more favourable

• configuration proved to be potent β-glucosidase inhibitors that showed only weak activity towards α-glucosidase and α-mannosidase [78][79][80]. Malto-oligosaccharides and analogues of di- and trisaccharides containing polyhydroxylated azepane moieties are glucosidase or HIV/FIV-protease blockers, or both. As

Synthesis of densely functionalized enantiopure indolizidines by ring- closing metathesis (RCM) of hydroxylamines from carbohydrate- derived nitrones

• Marco Bonanni,
• Marco Marradi,
• Francesca Cardona,
• Stefano Cicchi and
• Andrea Goti

Beilstein J. Org. Chem. 2007, 3, No. 44, doi:10.1186/1860-5397-3-44

• solution of MeOH afforded protonated indolizidines 21–22 in good yields (Scheme 4). Analogously, deprotection of 20 gave pyrrolazepine 23, which displayed good inhibition of α-glucosidase from yeast (90% at 1 mM).[23] Compounds 17 and 23, containing an azepane moiety, might be of biological interest as