Three-component N-alkenylation of azoles with alkynes and iodine(III) electrophile: synthesis of multisubstituted N-vinylazoles

• Jun Kikuchi,
• Roi Nakajima and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2024, 20, 891–897, doi:10.3762/bjoc.20.79

• , producing the vicinal N-heterocycle-substituted olefin 9 as a mixture of stereoisomers in 65% yield. Finally, 4aa proved to be a viable nucleophilic VBX for the carboiodanation of 3-methoxybenzyne [35], furnishing the new ortho-alkenylated arylbenziodoxole 10 with exclusive C–C bond formation at the distal

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• at the α-position have not yet been studied. Typically, two primary strategies are employed to build an N-heterocycle-glutarimide diad. The first involves assembling a heterocyclic fragment utilizing glutamic acid imide (2, Scheme 1, route A), while the second involves alkylating NH-heterocycle with

• lactams). The second approach, which asserts its universality, frequently displays inadequate yield of target compounds. As such, the endeavour to discover novel approaches for synthesizing N-heterocycle-glutarimide ensembles of type 1 persists as imperative. Aliphatic diazocarbonyl reagents are widely

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• synthesis from acyclic iodonium ylide 31 and tertiary amines. N-Heterocycle synthesis from acyclic iodonium ylide 31 and secondary amines. Indoline synthesis from acyclic iodonium ylides 39 and tertiary

Sulfate radical anion-induced benzylic oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines

• Joydev K. Laha,
• Pankaj Gupta and
• Amitava Hazra

Beilstein J. Org. Chem. 2023, 19, 771–777, doi:10.3762/bjoc.19.57

• -arylsulfonylimine 2, generated in situ from the corresponding N-(arylsulfonyl)benzylamine 1, undergoes transimination with the ortho-substituted aniline 3 to form imine 3ab via 3aa. Subsequent intramolecular nucleophilic addition in imine 3ab produces intermediate 3ac, which upon oxidation delivers the desired N

• -heterocycle 4. Conclusion In conclusion, we have developed a complementary approach to the currently available methods for the oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines using K2S2O8 and pyridine as a base. While N-arylimines are difficult to prepare by the oxidation of N-aryl(benzyl

Synthesis and reactivity of azole-based iodazinium salts

• Thomas J. Kuczmera,
• Annalena Dietz,
• Andreas Boelke and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2023, 19, 317–324, doi:10.3762/bjoc.19.27

• chemistry of hypervalent iodine species in all their variety, particularly those containing N-heterocycles either as tethered stabilizing ligands or as an inclusive part of a cyclic iodonium salt [26][27][28][29][30][31]. We prepared five-membered, N-heterocycle-containing iodoliums 2 and investigated their

• novel azoiodazinium salts (Figure 3). An N4–I1 distance of 2.540 Å with a typical T-shape structure (N4–I1–C1 angle 185.74°) implies a significant interaction between the N-heterocycle and the iodine atom for the ortho-pyrazole-substituted derivative 5bb [35]. However, the presence of an ortho-methyl

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• pyridine derivatives have been developed through the intramolecular or intermolecular tandem addition annulation/functionalization of alkynes with some N-containing compounds, such as nitriles, oximes, and imines [15][16][17][18][19]. The pyrrole structural motif is also an invaluable five-membered N

• -heterocycle that is widely used in pharmaceuticals, photoelectric materials, and functional materials [20][21][22][23]. Many pyrrole derivatives play a significant role in the life science and medicine domains due to the good bioactivities, such as antitumor, anti-HIV, and anti-HSV-1 activity [24][25][26][27

Tuneable access to indole, indolone, and cinnoline derivatives from a common 1,4-diketone Michael acceptor

• Dalel El-Marrouki,
• Sabrina Touchet,
• Abderrahmen Abdelli,
• Hédi M’Rabet,
• Mohamed Lotfi Efrit and
• Philippe C. Gros

Beilstein J. Org. Chem. 2020, 16, 1722–1731, doi:10.3762/bjoc.16.144

• -tetrahydrocinnoline) derivatives in moderate to excellent yields. Keywords: cinnoline; 1,4-diketone; indole; indolone; N-heterocycle; Introduction Nitrogen-containing heterocycles are widespread in plenty of molecules of interest, either in materials science, optics, electronics, or biology [1][2][3][4]. They are

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• transformation, the arene is first oxidized by the excited state of the photocatalyst, generating the arene radical cation I. The latter then undergoes a nucleophilic attack of the N-heterocycle, affording the radical adduct II. TEMPO and O2 act as oxidants for the formation of the final aromatic compound via

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• employed in diverse organic reactions, including Suzuki reactions [64], Sonogashira reactions [65], transesterifications of triglycerides [66], hydrogenation reactions [67], N-heterocycle syntheses [68], cleavage of propargyl phenol ethers [69], etc. [70][71][72][73][74][75]. In this review article, we

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• basicity in one ligand. The body discusses the synthetic protocols which focus on P–C, P–N-bond formation, substrate and nucleophile types and different N-heterocycle construction strategies. Selected references are given in relation to the applications of the ligands. Keywords: ligand synthesis; P,N

Thermal stability of N-heterocycle-stabilized iodanes – a systematic investigation

• Andreas Boelke,
• Yulia A. Vlasenko,
• Mekhman S. Yusubov,
• Boris J. Nachtsheim and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2019, 15, 2311–2318, doi:10.3762/bjoc.15.223

• Federation Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague, Czech Republic 10.3762/bjoc.15.223 Abstract The thermal stability of pseudocyclic and cyclic N-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-λ3-iodanes (NHIs) through thermogravimetric analysis

• stability with reactivity in a model oxygenation. Keywords: differential scanning calorimetry; hypervalent iodine; N-heterocycle; stability; thermogravimetry; Introduction Hypervalent iodine compounds, in particular aryl-λ3-iodanes, have found wide spread applications as oxidants and electrophilic group

• promising properties in terms of reactivity and stability. However, iodanes stabilized by nitrogen-based ligands, in particular N-heterocycles are still underexplored [22][23][24][25][26][27][28]. Recently, our groups investigated systematically cyclic and pseudocyclic N-heterocycle-stabilized iodanes (NHIs

Highly chemo-, enantio-, and diastereoselective [4 + 2] cycloaddition of 5H-thiazol-4-ones with N-itaconimides

• Shuai Qiu,
• Choon-Hong Tan and
• Zhiyong Jiang

Beilstein J. Org. Chem. 2016, 12, 2293–2297, doi:10.3762/bjoc.12.222

• to afford a spirocyclic sulfur-bridged N-heterocycle 4 in 70% yield and without compromising its ee value. Conclusion In conclusion, we have developed the first asymmetric reaction of 5H-thiazol-4-ones with N-itaconimides. By employing a DP-UAA catalyst, the reaction undergoes a [4 + 2] annulation

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• constructing biologically important spirooxindoles. In addition to the above mentioned metal- and organocatalyzed asymmetric synthesis of 3-hydroxyoxindoles, Zhao et al. reported a complementary strategy that employed the chiral acylazolium species (prepared from aldehydes and N-heterocycle carbenes) to

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

• -existing substituents. 3.5 Eight-membered rings The eight-membered ring is the largest stereoselectively fluorinated N-heterocycle that has been investigated to date [20]. O’Hagan and co-workers investigated the structure 24 (Figure 7), and calculated that the axial conformation of 24 should be strongly

• -membered N-heterocycle 24 prefers an axial orientation of the fluorine substituent, giving two C–F…N+ interactions. Some iminosugars are “privileged structures” that serve as valuable drug leads. Fluorinated iminosugar analogues 32–34 illuminate the binding interactions of the α-glycosidase inhibitor 28

One-pot four-component synthesis of pyrimidyl and pyrazolyl substituted azulenes by glyoxylation–decarbonylative alkynylation–cyclocondensation sequences

• Charlotte F. Gers,
• Julia Rosellen,
• Eugen Merkul and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1173–1181, doi:10.3762/bjoc.7.136

• [48]. Our retrosynthetic analysis (Scheme 3) suggests that a wide range of N-heterocycle-substituted azulenes should be accessible through Michael addition–cyclocondensation of azulenylynones with binucleophiles. Azulenylynones in turn could be simply disconnected by our glyoxylation–decarbonylative

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

• the 6-membered N-heterocycle in 133. Protection of the amino alcohols trans-132 and cis-132, as the corresponding trans and cis oxazolidinones, afforded a mixture of diastereomers that were not separable on silica gel. After effecting RCM (2nd-generation Grubbs catalyst 5, 5 mol %) on this mixture

Synthesis of some novel hydrazono acyclic nucleoside analogues

• Mohammad N. Soltani Rad,
• Ali Khalafi-Nezhad and
• Somayeh Behrouz

Beilstein J. Org. Chem. 2010, 6, No. 49, doi:10.3762/bjoc.6.49

• mixture of the appropriate N-heterocycle (0.01 mol), the 2-bromoacetophenone (0.012 mol), anhydrous TEA (1.01 g, 0.01 mol) and a catalytic amount of TBAB (0.1 g) was dissolved in dry acetonitrile (40 mL). The mixture was then heated at reflux for 10 h (TLC control). The solvent was evaporated at reduced

Prins fluorination cyclisations: Preparation of 4-fluoro-pyran and -piperidine heterocycles

• Guillaume G. Launay,
• Alexandra M. Z. Slawin and
• David O'Hagan

Beilstein J. Org. Chem. 2010, 6, No. 41, doi:10.3762/bjoc.6.41

• bonds, particularly concomitant with O- and N-heterocycle assembly. In general the diastereoselectivities are poor in these reactions, however they can be improved in the oxa-Prins case by lowering the temperature of the reactions to −20 °C. Both these oxa- and aza-Prins reactions can be significantly