Search for "ethanol" in Full Text gives 751 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202
Graphical Abstract
Scheme 1: Synthesis of catechol-containing compounds 1–9.
Figure 1: The X-ray structure of catechol 5 (the thermal ellipsoids of 50% probability). The hydrogen atoms e...
Figure 2: The X-ray structures of catechols 6 (a) and 8 (b) (the thermal ellipsoids of 50% probability). The ...
Figure 3: Fragment of the pack of catechol 5 in crystal (the H-bonds and π–π interactions are shown as dotted...
Figure 4: The interactions in pair of independent molecules A and B of 6 in crystal 6·0.5CH3CN (the H-bonds a...
Figure 5: Fragment of the pack of catechol 8 in crystal (the H-bonds and π–π interactions are shown as dotted...
Scheme 2: Electrochemical transformations of compounds 1–3.
Figure 6: The CV curve of 2 at the potential range from −0.50 to 1.60 V (CH3CN, GC electrode, Ag/AgCl/KCl(sat...
Figure 7: The CV curves of 3 at the potential ranges from –0.5 to 1.2 V (curve 1); from –0.5 to 2.0 V (curve ...
Figure 8: The CV curves of 7 at the potential ranges from –0.5 to 1.3 V (curve 1); from –0.5 to 1.8 V (curve ...
Scheme 3: Proposed mechanism of an electrooxidation of compounds 6–8.
Figure 9: The level of TBARS in rat liver homogenates in vitro, in the presence of compounds 1–9, Trolox, and...
Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199
Graphical Abstract
Figure 1: Overall chemical proteomics strategy to identify protein targets of natural products (NPs) and simi...
Figure 2: A) Design of mostly used photo-crosslinking groups. B) Mass spectrometry properties of proteins PTM...
Figure 3: Direct and indirect approach to identify protein targets and representative chemical proteomics wor...
Figure 4: Products of the CuAAC side reactions.
Figure 5: Search possibilities on peptide-level characterization. A) Comparison of DDA and DIA techniques. B)...
Figure 6: In-gel analysis using a tag with fluorophore (A) or via shift-assay (B).
Figure 7: Reporter linkers. A) DMP-tag. B) AzidoTMT tag. C) SOX-tag. D) Imidazolium tag. *A star indicates th...
Figure 8: Biotin and desthiobition-based sample linkers and their associated diagnostic peaks. A) Structure o...
Figure 9: A) isoDTB linker and probe-specific diagnostic ions (B). *A star indicates the possible introductio...
Figure 10: TEV-cleavable linker structure with its characteristic diagnostic ions (A) and probe-specific diagn...
Figure 11: A) Structure of the full length DADPS linker and remaining part after cleavage. B) Diagnostic ions....
Figure 12: Diagnostic peaks included in the search identify higher numbers of modified PSMs and peptides using...
Figure 13: An alternative DADPS linker.
Figure 14: Chemical structure of the trifunctional trypsin cleavable AzKTB linker.
Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178
Graphical Abstract
Scheme 1: Consecutive three-component synthesis of pyrazoles 1 via in situ-formed 1,3-diketones 2 [44].
Scheme 2: Consecutive three-component synthesis of 4-ethoxycarbonylpyrazoles 5 via SmCl3-catalyzed acylation ...
Scheme 3: Consecutive four-component synthesis of 1-(thiazol-2-yl)pyrazole-3-carboxylates 8 [51].
Scheme 4: Three-component synthesis of thiazolylpyrazoles 17 via in situ formation of acetoacetylcoumarins 18 ...
Scheme 5: Consecutive pseudo-four-component and four-component synthesis of pyrazoles 21 from sodium acetylac...
Scheme 6: Consecutive three-component synthesis of 1-substituted pyrazoles 24 from boronic acids, di(Boc)diim...
Scheme 7: Consecutive three-component synthesis of N-arylpyrazoles 25 via in situ formation of aryl-di(Boc)hy...
Scheme 8: Consecutive three-component synthesis of 1,3,4-substituted pyrazoles 27 and 28 from methylhydrazine...
Scheme 9: Consecutive three-component synthesis of 4-allylpyrazoles 32 via oxidative allylation of 1,3-dicarb...
Scheme 10: Pseudo-five-component synthesis of tris(pyrazolyl)methanes 35 [61].
Scheme 11: Pseudo-three-component synthesis of 5-(indol-3-yl)pyrazoles 39 from 1,3,5-triketones 38 [64].
Scheme 12: Three-component synthesis of thiazolylpyrazoles 43 [65].
Scheme 13: Three-component synthesis of triazolo[3,4-b]-1,3,4-thiadiazin-3-yl substituted 5-aminopyrazoles 47 [67]....
Scheme 14: Consecutive three-component synthesis of 5-aminopyrazoles 49 via formation of β-oxothioamides 50 [68].
Scheme 15: Synthesis of 3,4-biarylpyrazoles 52 from aryl halides, α-bromocinnamaldehyde, and tosylhydrazine vi...
Scheme 16: Consecutive three-component synthesis of 3,4-substituted pyrazoles 57 from iodochromones 55 by Suzu...
Scheme 17: Pseudo-four-component synthesis of pyrazolyl-2-pyrazolines 59 by ring opening/ring closing cyclocon...
Scheme 18: Consecutive three-component synthesis of pyrazoles 61 [77].
Scheme 19: Three-component synthesis of pyrazoles 62 from malononitrile, aldehydes, and hydrazines [78-90].
Scheme 20: Four-component synthesis of pyrano[2,3-c]pyrazoles 63 [91].
Scheme 21: Three-component synthesis of persubstituted pyrazoles 65 from aldehydes, β-ketoesters, and hydrazin...
Scheme 22: Three-component synthesis of pyrazol-4-carbodithioates 67 [100].
Scheme 23: Regioselective three-component synthesis of persubstituted pyrazoles 68 catalyzed by ionic liquid [...
Scheme 24: Consecutive three-component synthesis of 4-halopyrazoles 69 and anellated pyrazoles 70 [102].
Scheme 25: Three-component synthesis of 2,2,2-trifluoroethyl pyrazole-5-carboxylates 72 [103].
Scheme 26: Synthesis of pyrazoles 75 in a one-pot process via carbonylative Heck coupling and subsequent cycli...
Scheme 27: Copper-catalyzed three-component synthesis of 1,3-substituted pyrazoles 76 [105].
Scheme 28: Pseudo-three-component synthesis of bis(pyrazolyl)methanes 78 by ring opening-ring closing cyclocon...
Scheme 29: Three-component synthesis of 1,4,5-substituted pyrazoles 80 [107].
Scheme 30: Consecutive three-component synthesis of 3,5-bis(fluoroalkyl)pyrazoles 83 [111].
Scheme 31: Consecutive three-component synthesis of difluoromethanesulfonyl-functionalized pyrazole 88 [114].
Scheme 32: Consecutive three-component synthesis of perfluoroalkyl-substituted fluoropyrazoles 91 [115].
Scheme 33: Regioselective consecutive three-component synthesis of 1,3,5-substituted pyrazoles 93 [116].
Scheme 34: Three-component synthesis of pyrazoles 96 mediated by trimethyl phosphite [117].
Scheme 35: One-pot synthesis of pyrazoles 99 via Liebeskind–Srogl cross-coupling/cyclocondensation [118].
Scheme 36: Synthesis of 1,3,5-substituted pyrazoles 101 via domino condensation/Suzuki–Miyaura cross-coupling ...
Scheme 37: Consecutive three-component synthesis of 1,3,5-trisubstituted pyrazoles 102 and 103 by Sonogashira ...
Scheme 38: Polymer analogous consecutive three-component synthesis of pyrazole-based polymers 107 [132].
Scheme 39: Synthesis of 1,3,5-substituted pyrazoles 108 by sequentially Pd-catalyzed Kumada–Sonogashira cycloc...
Scheme 40: Consecutive four-step one-pot synthesis of 1,3,4,5-substituted pyrazoles 110 [137].
Scheme 41: Four-component synthesis of pyrazoles 113, 115, and 117 via Sonogashira coupling and subsequent Suz...
Scheme 42: Consecutive four- or five-component synthesis for the preparation of 4-pyrazoly-1,2,3-triazoles 119...
Scheme 43: Four-component synthesis of pyrazoles 121 via alkynone formation by carbonylative Pd-catalyzed coup...
Scheme 44: Preparation of 3-azulenyl pyrazoles 124 by glyoxylation, decarbonylative Sonogashira coupling, and ...
Scheme 45: Four-component synthesis of a 3-indoloylpyrazole 128 [147].
Scheme 46: Two-step synthesis of 5-acylpyrazoles 132 via glyoxylation-Stephen–Castro sequence and subsequent c...
Scheme 47: Copper on iron mediated consecutive three-component synthesis of 3,5-substituted pyrazoles 136 [150].
Scheme 48: Consecutive three-component synthesis of 3-substituted pyrazoles 141 by Sonogashira coupling and su...
Scheme 49: Consecutive three-component synthesis of pyrazoles 143 initiated by Cu(I)-catalyzed carboxylation o...
Scheme 50: Consecutive three-component synthesis of benzamide-substituted pyrazoles 146 starting from N-phthal...
Scheme 51: Consecutive three-component synthesis of 1,3,5-substituted pyrazoles 148 [156].
Scheme 52: Three-component synthesis of 4-ninhydrin-substituted pyrazoles 151 [158].
Scheme 53: Consecutive four-component synthesis of 4-(oxoindol)-1-phenylpyrazole-3-carboxylates 155 [159].
Scheme 54: Three-component synthesis of pyrazoles 160 [160].
Scheme 55: Consecutive three-component synthesis of pyrazoles 165 [162].
Scheme 56: Consecutive three-component synthesis of 3,5-disubstituted and 3-substituted pyrazoles 168 and 169 ...
Scheme 57: Three-component synthesis of 3,4,5-substituted pyrazoles 171 via 1,3-dipolar cycloaddition of vinyl...
Scheme 58: Three-component synthesis of pyrazoles 173 and 174 from aldehydes, tosylhydrazine, and vinylidene c...
Scheme 59: Three-component synthesis of pyrazoles 175 from glyoxyl hydrates, tosylhydrazine, and electron-defi...
Scheme 60: Pseudo-four-component synthesis of pyrazoles 177 from glyoxyl hydrates, tosylhydrazine, and aldehyd...
Scheme 61: Consecutive three-component synthesis of pyrazoles 179 via Knoevenagel-cycloaddition sequence [179].
Scheme 62: Three-component synthesis of 5-dimethylphosphonate substituted pyrazoles 182 from aldehydes, the Be...
Scheme 63: Consecutive three-component synthesis of 5-(dimethyl phosphonate)-substituted pyrazoles 185 from al...
Scheme 64: Three-component synthesis of 5-(dimethyl phosphonate)-substituted pyrazoles 187 from aldehydes, the...
Scheme 65: Three-component synthesis of 5-diethylphosphonate/5-phenylsulfonyl substituted pyrazoles 189 from a...
Scheme 66: Pseudo-three-component synthesis of 3-(dimethyl phosphonate)-substituted pyrazoles 190 [185].
Scheme 67: Three-component synthesis of 3-trifluoromethylpyrazoles 193 [186].
Scheme 68: Consecutive three-component synthesis of 5-stannyl-substituted 4-fluoropyrazole 197 [191,192].
Scheme 69: Pseudo-three-component synthesis of 3,5-diacyl-4-arylpyrazoles 199 [195].
Scheme 70: Three-component synthesis of pyrazoles 204 via nitrilimines [196].
Scheme 71: Three-component synthesis of 1,3,5-substituted pyrazoles 206 via formation of nitrilimines and sali...
Scheme 72: Pseudo four-component synthesis of pyrazoles 209 from acetylene dicarboxylates 147, hydrazonyl chlo...
Scheme 73: Consecutive three-component synthesis of pyrazoles 213 via syndnones 214 [200].
Scheme 74: Consecutive three-component synthesis of pyrazoles 216 via in situ-formed diazomethinimines 217 [201].
Scheme 75: Consecutive three-component synthesis of 3-methylthiopyrazoles 219 from aldehydes, hydrazine, and 1...
Scheme 76: Three-component synthesis of 1,3,5-substituted pyrazoles 220 from aldehydes, hydrazines, and termin...
Scheme 77: Three-component synthesis of 1,3,4,5-substituted pyrazoles 222 from aldehydes, hydrazines, and DMAD ...
Scheme 78: Pseudo three-component synthesis of pyrazoles 224 from sulfonyl hydrazone and benzyl acrylate under...
Scheme 79: Titanium-catalyzed consecutive four-component synthesis of pyrazoles 225 via enamino imines 226 [211]. a...
Scheme 80: Titanium-catalyzed three-component synthesis of pyrazoles 227 via enhydrazino imine complex interme...
Scheme 81: Pseudo-three-component synthesis of pyrazoles 229 via Glaser coupling of terminal alkynes and photo...
Scheme 82: Copper(II)acetate-mediated three-component synthesis of pyrazoles 232 [216].
Scheme 83: Copper-catalyzed three-component synthesis of 1,3,4-substituted pyrazole 234 from oxime acetates, a...
Scheme 84: Three-component synthesis of 3-trifluoroethylpyrazoles 239 [218].
Scheme 85: Pseudo-three-component synthesis of 1,4-bisulfonyl-substituted pyrazoles 242 [219].
Scheme 86: Three-component synthesis of 4-hydroxypyrazole 246 [221].
Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175
Graphical Abstract
Scheme 1: Synthesis of triazolopyridinium salts [34-36].
Scheme 2: Synthesis of pyrazoles [37].
Scheme 3: Synthesis of indazoles from ketone-derived hydrazones [38].
Scheme 4: Intramolecular C(sp2)–H functionalization of aldehyde-derived N-(2-pyridinyl)hydrazones for the syn...
Scheme 5: Synthesis of pyrazolo[4,3-c]quinoline derivatives [40].
Scheme 6: Synthesis of 1,3,4-oxadiazoles and Δ3-1,3,4-oxadiazolines [41].
Scheme 7: Synthesis of 1,3,4-oxadiazoles [43].
Scheme 8: Synthesis of 2-(1,3,4-oxadiazol-2-yl)anilines [44].
Scheme 9: Synthesis of fused s-triazolo perchlorates [45].
Scheme 10: Synthesis of 1-aryl and 1,5-disubstitued 1,2,4-triazoles [49].
Scheme 11: Synthesis of 1,3,5-trisubstituted 1,2,4-triazoles [50].
Scheme 12: Alternative synthesis of 1,3,5-trisubstituted 1,2,4-triazoles [51].
Scheme 13: Synthesis of 5-amino 1,2,4-triazoles [55].
Scheme 14: Synthesis of 1-arylpyrazolines [58].
Scheme 15: Synthesis of 3‑aminopyrazoles [60].
Scheme 16: Synthesis of [1,2,4]triazolo[4,3-a]quinolines [61].·
Scheme 17: Synthesis of 1,2,3-thiadiazoles [64].
Scheme 18: Synthesis of 5-thioxo-1,2,4-triazolium inner salts [65].
Scheme 19: Synthesis of 1-aminotetrazoles [66].
Scheme 20: C(sp2)–H functionalization of aldehyde-derived hydrazones: general mechanisms.
Scheme 21: C(sp2)–H functionalization of benzaldehyde diphenyl hydrazone [68,69].
Scheme 22: Phosphorylation of aldehyde-derived hydrazones [70].
Scheme 23: Azolation of aldehyde-derived hydrazones [72].
Scheme 24: Thiocyanation of benzaldehyde-derived hydrazone 122 [73].
Scheme 25: Sulfonylation of aromatic aldehyde-derived hydrazones [74].
Scheme 26: Trifluoromethylation of aromatic aldehyde-derived hydrazones [76].
Scheme 27: Electrooxidation of benzophenone hydrazones [77].
Scheme 28: Electrooxidative coupling of benzophenone hydrazones and alkenes [77].
Scheme 29: Electrosynthesis of α-diazoketones [78].
Scheme 30: Electrosynthesis of stable diazo compounds [80].
Scheme 31: Photoelectrochemical synthesis of alkenes through in situ generation of diazo compounds [81].
Scheme 32: Synthesis of nitriles [82].
Scheme 33: Electrochemical oxidation of ketone-derived NH-allylhydrazone [83].
Beilstein J. Org. Chem. 2024, 20, 1955–1966, doi:10.3762/bjoc.20.171
Graphical Abstract
Scheme 1: 1,2-Difluoroethylene synthesis from HFO-1123.
Scheme 2: 1,2-Difluoroethylene synthesis from CFC-112 and HCFC-132.
Scheme 3: 1,2-Difluoroethylene synthesis from HFC-143.
Scheme 4: 1,2-Difluoroethylene synthesis from HCFC-142 via HCFC-142a.
Scheme 5: 1,2-Difluoroethylene synthesis from CFO-1112.
Scheme 6: 1,2-Difluoroethylene synthesis from 1,2-dichloroethylene.
Scheme 7: 1,2-Difluoroethylene synthesis from perfluoropropyl vinyl ether.
Scheme 8: Deuteration reaction of 1,2-difluoroethylene.
Scheme 9: Halogen addition to 1,2-difluoroethylene.
Scheme 10: Hypohalite addition to 1,2-difluoroethylene.
Scheme 11: N-Bromobis(trifluoromethyl)amine addition to 1,2-difluoroethylene.
Scheme 12: N-Chloroimidobis(sulfonyl fluoride) addition to 1,2-difluoroethylene.
Scheme 13: Trichlorosilane addition to 1,2-difluoroethylene.
Scheme 14: SF5Br addition to 1,2-difluoroethylene.
Scheme 15: PCl3/O2 addition to 1,2-difluoroethylene.
Scheme 16: Reaction of tetramethyldiarsine with 1,2-difluoroethylene.
Scheme 17: Reaction of trichlorofluoromethane with 1,2-difluoroethylene.
Scheme 18: Addition of perfluoroalkyl iodides to 1,2-difluoroethylene.
Scheme 19: Cyclopropanation of 1,2-difluoroethylene.
Scheme 20: Diels–Alder reaction of 1,2-difluoroethylene and hexachlorocyclopentadiene.
Scheme 21: Cycloaddition reaction of 1,2-difluoroethylene and fluorinated ketones.
Scheme 22: Cycloaddition reaction of 1,2-difluoroethylene and perfluorinated aldehydes.
Scheme 23: Photochemical cycloaddition of 1,2-difluoroethylene and hexafluorodiacetyl.
Scheme 24: Reaction of 1,2-difluoroethylene with difluorosilylene.
Scheme 25: Reaction of 1,2-difluoroethylene with aryl iodides.
Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170
Graphical Abstract
Figure 1: Indazole-containing bioactive molecules.
Figure 2: Tautomerism of indazole.
Scheme 1: NMR, NOE, and yield data of compounds 8 and 9.
Scheme 2: Synthesis of compounds P1 and P2.
Figure 3: DFT-calculated deprotonation of 6 with Cs2CO3 in implicit THF with the temperature of the calculati...
Figure 4: DFT-calculated Cs+-coordinated complexes with different enolate forms of 6(N-H) calculated as isola...
Figure 5: DFT-calculated reaction coordinate diagram for the reaction of 6 under conditions A. Concerning con...
Figure 6: DFT-calculated energy for the deprotonation of 6 by the DMAD anion.
Figure 7: DFT-calculations concerning a coordinated Mitsunobu reaction pathway.
Figure 8: Reaction coordinate diagram of 6(N-H) reacting under conditions B. All calculated energies in kcal/...
Figure 9: Reaction of 18 under conditions A and B (top), and proposed chelation/coordination pathways to acco...
Figure 10: DFT-calculated reaction coordinate diagram for the reaction of 18 under conditions A.
Figure 11: DFT-calculated reaction coordinate diagram for the reaction of 18 under conditions B. Ball-and-stic...
Scheme 3: Reaction of 21 under conditions A and B; amultiple purifications; bdetermined by LC–MS.
Figure 12: DFT-calculated transition-state structures and energies of 21 under conditions A (top) and conditio...
Beilstein J. Org. Chem. 2024, 20, 1922–1932, doi:10.3762/bjoc.20.168
Graphical Abstract
Scheme 1: Known and improved synthetic strategies to access α-(hetero)aryl-amino acids.
Scheme 2: Reformatsky reagent production.
Scheme 3: Scope of ethyl heteroarylacetates. Isolated yields are given. *Dark reactions were carried out for ...
Scheme 4: Telescoped flow synthesis of heteroarylacetates.
Scheme 5: Potential routes for the preparation of oximes.
Scheme 6: Oxime group insertion step.
Scheme 7: Amino ester production: general scheme, scope and gram scale experiment. The numbers in brackets re...
Scheme 8: Reactions scheme and results for the on-DNA experiments. The reported values represent the normaliz...
Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162
Graphical Abstract
Scheme 1: Mechanism of the GBB reaction.
Scheme 2: Comparison of the performance of Sc(OTf)3 with some RE(OTf)3 in a model GBB reaction. Conditions: a...
Scheme 3: Comparison of the performance of various Brønsted acid catalysts in the synthesis of GBB adduct 6. ...
Scheme 4: Synthesis of Brønsted acidic ionic liquid catalyst 7. Conditions: a) neat, 60 °C, 24 h; b) TfOH, DC...
Scheme 5: Aryliodonium derivatives as organic catalysts in the GBB reaction. In the box the proposed binding ...
Scheme 6: DNA-encoded GBB reaction in micelles made of amphiphilic polymer 13. Conditions: a) 13 (50 equiv), ...
Scheme 7: GBB reaction catalyzed by cyclodextrin derivative 14. Conditions: a) 14 (1 mol %), water, 100 °C, 4...
Scheme 8: Proposed mode of activation of CALB. a) activation of the substrates; b) activation of the imine; c...
Scheme 9: One-pot GBB reaction–Suzuki coupling with a bifunctional hybrid biocatalyst. Conditions: a) Pd(0)-C...
Scheme 10: GBB reaction employing 5-HMF (23) as carbonyl component. Conditions: a) TFA (20 mol %), EtOH, 60 °C...
Scheme 11: GBB reaction with β-C-glucopyranosyl aldehyde 26. Conditions: a) InCl3 (20 mol %), MeOH, 70 °C, 2–3...
Scheme 12: GBB reaction with diacetylated 5-formyldeoxyuridine 29, followed by deacetylation of GBB adduct 30....
Scheme 13: GBB reaction with glycal aldehydes 32. Conditions: a) HFIP, 25 °C, 2–4 h.
Scheme 14: Vilsmeier–Haack formylation of 6-β-acetoxyvouacapane (34) and subsequent GBB reaction. Conditions: ...
Scheme 15: GBB reaction of 4-formlyl-PCP 37. Conditions: a) HOAc or HClO4, MeOH/DCM (2:3), rt, 3 d.
Scheme 16: GBB reaction with HexT-aldehyde 39. Conditions: a) 39 (20 nmol) and amidine (20 μmol), MeOH, rt, 6 ...
Scheme 17: GBB reaction of 2,4-diaminopirimidine 41. Conditions: a) Sc(OTf)3 (20 mol %), MeCN, 120 °C (MW), 1 ...
Scheme 18: Synthesis of N-edited guanine derivatives from 3,6-diamine-1,2,4-triazin-5-one 44. Conditions: a) S...
Scheme 19: Synthesis of 2-aminoimidazoles 49 by a Mannich-3CR followed by a one-pot intramolecular oxidative a...
Scheme 20: On DNA Suzuki–Miyaura reaction followed by GBB reaction. Conditions: a) CsOH, sSPhos-Pd-G2; b) AcOH...
Scheme 21: One-pot cascade synthesis of 5-iminoimidazoles. Conditions: a) Na2SO4, DMF, 220 °C (MW).
Scheme 22: GBB reaction of 5-amino-1H-imidazole-4-carbonile 57. Conditions: a) HClO4 (5 mol %), MeOH, rt, 24 h....
Scheme 23: One-pot cascade synthesis of indole-imidazo[1,2,a]pyridine hybrids. In blue the structural motif in...
Scheme 24: One-pot cascade synthesis of fused polycyclic indoles 67 or 69 from indole-3-carbaldehyde. Conditio...
Scheme 25: One-pot cascade synthesis of linked- and bridged polycyclic indoles from indole-2-carbaldehyde (70)...
Scheme 26: One-pot cascade synthesis of pentacyclic dihydroisoquinolines (X = N or CH). In blue the structural...
Scheme 27: One-pot stepwise synthesis of imidazopyridine-fused benzodiazepines 85. Conditions: a) p-TsOH (20 m...
Scheme 28: One-pot stepwise synthesis of benzoxazepinium-fused imidazothiazoles 89. Conditions: a) Yb(OTf)3 (2...
Scheme 29: One-pot stepwise synthesis of fused imidazo[4,5,b]pyridines 95. Conditions: a) HClO4, MeOH, rt, ove...
Scheme 30: Synthesis of heterocyclic polymers via the GBB reaction. Conditions: a) p-TsOH, EtOH, 70 °C, 24 h.
Scheme 31: One-pot multicomponent reaction towards the synthesis of covalent organic frameworks via the GBB re...
Scheme 32: One-pot multicomponent reaction towards the synthesis of covalent organic frameworks via the GBB re...
Scheme 33: GBB-like multicomponent reaction towards the synthesis of benzothiazolpyrroles (X = S) and benzoxaz...
Scheme 34: GBB-like multicomponent reaction towards the formation of imidazo[1,2,a]pyridines. Conditions: a) I2...
Scheme 35: Post-functionalization of GBB products via Ugi reaction. Conditions a) HClO4, DMF, rt, 24 h; b) MeO...
Scheme 36: Post-functionalization of GBB products via Click reaction. Conditions: a) solvent-free, 150 °C, 24 ...
Scheme 37: Post-functionalization of GBB products via cascade alkyne–allene isomerization–intramolecular nucle...
Scheme 38: Post-functionalization of GBB products via metal-catalyzed intramolecular N-arylation. In red and b...
Scheme 39: Post-functionalization of GBB products via isocyanide insertion (X = N or CH). Conditions: a) HClO4...
Scheme 40: Post-functionalization of GBB products via intramolecular nucleophilic addition to nitriles. Condit...
Scheme 41: Post-functionalization of GBB products via Pictet–Spengler cyclization. Conditions: a) 4 N HCl/diox...
Scheme 42: Post-functionalization of GBB products via O-alkylation. Conditions: a) TFA (20 mol %), EtOH, 120 °...
Scheme 43: Post-functionalization of GBB products via macrocyclization (X = -CH2CH2O-, -CH2-, -(CH2)4-). Condi...
Figure 1: Antibacterial activity of GBB-Ugi adducts 113 on both Gram-negative and Gram-positive strains.
Scheme 44: GBB multicomponent reaction using trimethoprim as the precursor. Conditions: a) Yb(OTf)3 or Y(OTf)3...
Figure 2: Antibacterial activity of GBB adducts 152 against MRSA and VRE; NA = not available.
Figure 3: Antibacterial activity of GBB adduct 153 against Leishmania amazonensis promastigotes and amastigot...
Figure 4: Antiviral and anticancer evaluation of the GBB adducts 154a and 154b. In vitro antiproliferative ac...
Figure 5: Anticancer activity of the GBB-furoxan hybrids 145b, 145c and 145d determined through antiprolifera...
Scheme 45: Synthesis and anticancer activity of the GBB-gossypol conjugates. Conditions: a) Sc(OTf)3 (10 mol %...
Figure 6: Anticancer activity of polyheterocycles 133a and 136a against human neuroblastoma. Clonogenic assay...
Figure 7: Development of GBB-adducts 158a and 158b as PD-L1 antagonists. HTRF assays were carried out against...
Figure 8: Development of imidazo[1,2-a]pyridines and imidazo[1,2-a]pyrazines as TDP1 inhibitors. The SMM meth...
Figure 9: GBB adducts 164a–c as anticancer through in vitro HDACs inhibition assays. Additional cytotoxic ass...
Figure 10: GBB adducts 165, 166a and 166b as anti-inflammatory agents through HDAC6 inhibition; NA = not avail...
Scheme 46: GBB reaction of triphenylamine 167. Conditions: a) NH4Cl (10 mol %), MeOH, 80 °C (MW), 1 h.
Scheme 47: 1) Modified GBB-3CR. Conditions: a) TMSCN (1.0 equiv), Sc(OTf)3 (0.2 equiv), MeOH, 140 °C (MW), 20 ...
Scheme 48: GBB reaction to assemble imidazo-fused heterocycle dimers 172. Conditions: a) Sc(OTf)3 (20 mol %), ...
Figure 11: Model compounds 173 and 174, used to study the acid/base-triggered reversible fluorescence response...
Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156
Graphical Abstract
Scheme 1: The use of α,β-unsaturated aldehydes in the Ugi reaction.
Scheme 2: Comparison of isocyanide conversion conditions.
Figure 1: Azomethines based on ethyl 4-acetyl-3,5-dimethyl-1H-pyrrole-2-carboxylate and 4-[(E)-1-chloro-3-oxo...
Figure 2: Molecular structure of ethyl (Z)-4-(3-(N-(4-bromophenyl)-2-chloroacetamido)-4-(tert-butylamino)-1-c...
Scheme 3: Hydrolysis of Ugi bisamide 5d in the presence of HCl. Conditions: (A) 5 equiv HCl, MeOH, 80 °C, 3 h...
Figure 3: Molecular structure of ethyl (E)-4-(4-(tert-butylamino)-3,4-dioxobut-1-en-1-yl)-3,5-dimethyl-1H-pyr...
Figure 4: Molecular structure of ethyl 4-(3-(N-(4-bromophenyl)-2-chloroacetamido)-4-(tert-butylamino)-4-oxobu...
Scheme 4: The Ugi-4CR with the participation of p-anisidine and benzyl isocyanide.
Scheme 5: Successful attempt at tandem one-pot coupling of the Ugi-4CR reaction and post-transformation of th...
Scheme 6: Plausible transformation sequence of the formation of amides 10 and ketobisamides 12.
Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152
Graphical Abstract
Figure 1: Steroidal spiro heterocycles with remarkable pharmacological activity.
Scheme 1: Synthesis of the spirooxetanone 2. a) t-BuOK, THF, rt, 16%.
Scheme 2: Synthesis of the 17-spirooxetane derivative 7. a) HC≡C(CH2)2CH2OTBDPS, n-BuLi, THF, BF3·Et2O, −78 °...
Scheme 3: Pd-catalyzed carbonylation of steroidal alkynols to produce α-methylene-β-lactones at C-3 and C-17 ...
Scheme 4: Catalyst-free protocol to obtain functionalized spiro-lactones by an intramolecular C–H insertion. ...
Scheme 5: One-pot procedure from dienamides to spiro-β-lactams. a) 1. Ac2O, DMAP, Et3N, CH2Cl2, 2. malononitr...
Scheme 6: Spiro-γ-lactone 20 afforded from 7α-alkanamidoestrone derivative 17. a) HC≡CCH2OTHP, n-BuLi, THF, –...
Scheme 7: Synthesis of the 17-spiro-γ-lactone 23, a key intermediate to obtain spironolactone. a) Ethyl propi...
Scheme 8: Synthetic pathway to obtain 17-spirodihydrofuran-3(2H)-ones from 17-oxosteroids. a) 1-Methoxypropa-...
Scheme 9: One-pot procedure to obtain 17-spiro-2H-furan-3-one compounds. a) NaH, diethyl oxalate, benzene, rt...
Scheme 10: Synthesis of 17-spiro-2H-furan-3-one derivatives. a) RCH=NOH, N-chlorosuccinimide/CHCl3, 99%; b) H2...
Scheme 11: Intramolecular condensation of a γ-acetoxy-β-ketoester to synthesize spirofuranone 37. a) (CH3CN)2P...
Scheme 12: Synthesis of spiro 2,5-dihydrofuran derivatives. a) Allyl bromide, DMF, NaH, 0 °C to rt, 93%; b) G-...
Scheme 13: First reported synthesis of C-16 dispiropyrrolidine derivatives. a) Sarcosine, isatin, MeOH, reflux...
Scheme 14: Cycloadducts 47 with antiproliferative activity against human cancer cell lines. a) 1,4-Dioxane–MeO...
Scheme 15: Spiropyrrolidine compounds generated from (E)-16-arylidene steroids and different ylides. a) Acenap...
Scheme 16: 3-Spiropyrrolidines 52a–c obtained from ketones 50a–c. a) p-Toluenesulfonyl hydrazide, MeOH, rt; b)...
Scheme 17: 16-Spiropyrazolines from 16-methylene-13α-estrone derivatives. a) AgOAc, toluene, rt, 78–81%.
Scheme 18: 6-Spiroimidazolines 57 synthesized by a one-pot multicomponent reaction. a) R3-NC, T3P®, DMSO, 70 °...
Scheme 19: Synthesis of spiro-1,3-oxazolines 60, tested as progesterone receptor antagonist agents. a) CF3COCF3...
Scheme 20: Synthesis of spiro-1,3-oxazolidin-2-ones 63 and 66a,b. a) RNH2, EtOH, 70 °C, 70–90%; b) (CCl3O)2CO,...
Scheme 21: Formation of spiro 1,3-oxazolidin-2-one and spiro 2-substituted amino-4,5-dihydro-1,3-oxazoles from ...
Scheme 22: Synthesis of diastereomeric spiroisoxazolines 74 and 75. a) Ar-C(Cl)=N-OH, DIPEA, toluene, rt, 74 (...
Scheme 23: Spiro 1,3-thiazolidine derivatives 77–79 obtained from 2α-bromo-5α-cholestan-3-one 76. a) 2-aminoet...
Scheme 24: Method for the preparation of derivative 83. a) Benzaldehyde, MeOH, reflux, 77%; b) thioglycolic ac...
Scheme 25: Synthesis of spiro 1,3-thiazolidin-4-one derivatives from steroidal ketones. a) Aniline, EtOH, refl...
Scheme 26: Synthesis of spiro N-aryl-1,3-thiazolidin-4-one derivatives 91 and 92. a) Sulfanilamide, DMF, reflu...
Scheme 27: 1,2,4-Trithiolane dimers 94a–e selectively obtained from carbonyl derivatives. a) LR, CH2Cl2, reflu...
Scheme 28: Spiro 1,2,4-triazolidin-3-ones synthesized from semicarbazones. a) H2O2, CHCl3, 0 °C, 82–85%.
Scheme 29: Steroidal spiro-1,3,4-oxadiazoline 99 obtained in two steps from cholest-5-en-3-one (97). a) NH2NHC...
Scheme 30: Synthesis of spiro-1,3,4-thiadiazoline 101 by cyclization and diacetylation of thiosemicarbazone 100...
Scheme 31: Mono- and bis(1,3,4-thiadiazolines) obtained from estrane and androstane derivatives. a) H2NCSNHNH2...
Scheme 32: Different reaction conditions to synthesize spiro-1,3,2-oxathiaphospholanes 108 and 109.
Scheme 33: Spiro-δ-lactones derived from ADT and epi-ADT as inhibitors of 17β-HSDs. a) CH≡C(CH2)2OTHP, n-BuLi,...
Scheme 34: Spiro-δ-lactams 123a,b obtained in a five-step reaction sequence. a) (R)-(+)-tert-butylsulfinamide,...
Scheme 35: Steroid-coumarin conjugates as fluorescent DHT analogues to study 17-oxidoreductases for androgen m...
Scheme 36: 17-Spiro estradiolmorpholinones 130 bearing two types of molecular diversity. a) ʟ- or ᴅ-amino acid...
Scheme 37: Steroidal spiromorpholinones as inhibitors of enzyme 17β-HSD3. a) Methyl ester of ʟ- or ᴅ-leucine, ...
Scheme 38: Steroidal spiro-morpholin-3-ones achieved by N-alkylation or N-acylation of amino diols 141, follow...
Scheme 39: Straightforward method to synthesize a spiromorpholinone derivative from estrone. a) BnBr, K2CO3, CH...
Scheme 40: Pyrazolo[4,3-e][1,2,4]-triazine derivatives 152–154. a) 4-Aminoantipyrine, EtOH/DMF, reflux, 82%; b...
Scheme 41: One-pot procedure to synthesize spiro-1,3,4-thiadiazine derivatives. a) NH2NHCSCONHR, H2SO4, dioxan...
Scheme 42: 1,2,4-Trioxanes with antimalarial activity. a) 1. O2, methylene blue, CH3CN, 500 W tungsten halogen...
Scheme 43: Tetraoxanes 167 and 168 synthesized from ketones 163, 165 and 166. a) NaOH, iPrOH/H2O, 80 °C, 93%; ...
Scheme 44: 1,2,4,5-Tetraoxanes bearing a steroidal moiety and a cycloalkane. a) 30% H2O2/CH2Cl2/CH3CN, HCl, rt...
Scheme 45: Spiro-1,3,2-dioxaphosphorinanes obtained from estrone derivatives. a) KBH4, MeOH, THF or CH2Cl2; b)...
Scheme 46: Synthesis of steroidal spiro-ε-lactone 183. a) 1. Jones reagent, acetone, 0 °C to rt, 2. ClCOCOCl, ...
Scheme 47: Synthesis of spiro-2,3,4,7-tetrahydrooxepines 185 and 187 derived from mestranol and lynestrenol (38...
Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145
Graphical Abstract
Figure 1: General synthesis of triazinephosphonate compounds.
Scheme 1: Synthesis of diethyl phenylphosphonates 2, 4 and 6.
Scheme 2: Synthesis of (4-hydroxyphenyl)methylphosphonate 7 starting from [4-(benzyloxy)phenyl]methanol (8).
Scheme 3: Synthesis of diethyl [hydroxy(4-hydroxyphenyl)methyl]phosphonate (11) and tetraethyl [(4-hydroxyphe...
Scheme 4: Synthesis of diethyl phenylphosphonates 16 and 14.
Scheme 5: Synthesis of 4-aminophenyltriazinephosphonate derivatives TP1–TP3.
Figure 2: Partial view of 1H and 31P NMR spectra of 4-aminophenyltriazinephosphonate derivatives TP1–TP3.
Scheme 6: Synthesis of (4-hydroxyphenyl)triazinephosphonate derivatives TP4–TP6.
Figure 3: Partial view of 1H and 31P NMR spectra of (4-hydroxyphenyl)triazinephosphonate derivatives TP4–TP6.
Scheme 7: Attempted synthesis of triazinephosphonate TP7.
Figure 4: Preparation of the new doped membranes.
Figure 5: Comparison of in-plane proton conductivity vs RH of Nafion doped membranes, at 60 °C.
Beilstein J. Org. Chem. 2024, 20, 1436–1443, doi:10.3762/bjoc.20.126
Graphical Abstract
Figure 1: Molecular structure of compound 4a.
Figure 2: Molecular structure of compound 6g.
Scheme 1: Proposed reaction mechanism.
Beilstein J. Org. Chem. 2024, 20, 1412–1420, doi:10.3762/bjoc.20.123
Graphical Abstract
Figure 1: Representative examples of relevant N-fused heterocycles.
Scheme 1: Different acid-catalyzed six-membered ring cyclizations.
Scheme 2: Substrate scope for the assembly of suitably N-3-functionalized (thio)hydantoins 4a–r. aDCM was uti...
Scheme 3: Substrate scope of the iron(III)-catalyzed synthesis of functionalized heterocyclic N,O-aminals 5a–r...
Scheme 4: Proposed mechanism for the formation of N,O-aminals 5 and hemiaminals 6.
Scheme 5: Control mechanistic experiments.
Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119
Graphical Abstract
Figure 1: Generation of alkyl and acyl radicals via C–O bond breaking.
Figure 2: General photocatalytic mechanism.
Scheme 1: Photoredox-catalyzed hydroacylation of olefins with aliphatic carboxylic acids.
Scheme 2: Acylation–aromatization of p-quinone methides using carboxylic acids.
Scheme 3: Visible-light-induced deoxygenation–defluorination for the synthesis of γ,γ-difluoroallylic ketones....
Scheme 4: Photochemical hydroacylation of azobenzenes with carboxylic acids.
Scheme 5: Photoredox-catalyzed synthesis of flavonoids.
Scheme 6: Synthesis of O-thiocarbamates and photocatalytic reduction of O-thiocarbamates.
Scheme 7: Deoxygenative borylation of alcohols.
Scheme 8: Trifluoromethylation of O-alkyl thiocarbonyl substrates.
Scheme 9: Redox-neutral radical coupling reactions of alkyl oxalates and Michael acceptors.
Scheme 10: Visible-light-catalyzed and Ni-mediated syn-alkylarylation of alkynes.
Scheme 11: 1,2-Alkylarylation of alkenes with aryl halides and alkyl oxalates.
Scheme 12: Deoxygenative borylation of oxalates.
Scheme 13: Coupling of N-phthalimidoyl oxalates with various acceptors.
Scheme 14: Cross-coupling of O-alkyl xanthates with aryl halides via dual photoredox and nickel catalysis.
Scheme 15: Deoxygenative borylation of secondary alcohol.
Scheme 16: Deoxygenative alkyl radical generation from alcohols under visible-light photoredox conditions.
Scheme 17: Deoxygenative alkylation via alkoxy radicals against hydrogenation or β-fragmentation.
Scheme 18: Direct C–O bond activation of benzyl alcohols.
Scheme 19: Deoxygenative arylation of alcohols using NHC to activate alcohols.
Scheme 20: Deoxygenative conjugate addition of alcohol using NHC as alcohol activator.
Scheme 21: Synthesis of polysubstituted aldehydes.
Beilstein J. Org. Chem. 2024, 20, 1334–1340, doi:10.3762/bjoc.20.117
Graphical Abstract
Scheme 1: Synthesis of various triazole derivatives using Boulton–Katritzky rearrangement.
Scheme 2: Synthesis of hydrazone 3a.
Scheme 3: Synthesis of hydrazone 3b using phenylhydrazine hydrochloride.
Scheme 4: Synthesis of target 1,2,3-triazoles 4. Reaction conditions: 1 (0.5 mmol), arylhydrazine hydrochlori...
Figure 1: The X-ray crystal structure of compound 4g (CCDC 2343878).
Scheme 5: Proposed reaction mechanism.
Scheme 6: Reaction of 1d with hydrazine hydrate a.
Scheme 7: Synthesis of products 6. Reaction conditions: 1 (0.5 mmol), hydrazine hydrate (1.5 mmol, 0.08 g), E...
Scheme 8: Proposed reaction mechanism for the formation of products 6.
Scheme 9: Synthesis of methylated product 7.
Beilstein J. Org. Chem. 2024, 20, 1236–1245, doi:10.3762/bjoc.20.106
Graphical Abstract
Scheme 1: Left: Reaction mechanism of the 3-CR with Aza-H as the photocatalyst. Potentials are given vs SCE. ...
Figure 1: A) Room-temperature absorption (black) and emission (yellow) spectra of Aza-H recorded in MeCN/H2O ...
Figure 2: Mechanistic LFP experiments of 25 µM Aza-H with 4CP in MeCN/H2O (9:1) after 355 nm laser pulses. A)...
Figure 3: Mechanistic investigations of Aza-H with TsNa by LFP studies. A) Transient absorption measurements ...
Figure 4: Data sets employed for the calculation ΦISC of Aza-H based on the ground state bleach of Rubpy as t...
Figure 5: Stilbene isomerization and additional energy transfer experiments. A) and B) Triplet quenching expe...
Beilstein J. Org. Chem. 2024, 20, 1198–1206, doi:10.3762/bjoc.20.102
Graphical Abstract
Scheme 1: Ring cleavage and ring rearrangement reactions in the biosynthesis of atypical angucyclines.
Figure 1: HPLC traces of reaction mixtures of AlpG, AlpJ, Flu17, and JadG. (a) standards of prejadomycin (9),...
Figure 2: HPLC traces of reactions of JadG, AlpJ, or Flu17 quenched by SOD. (a) 8 + JadG + ʟ-isoleucine; (b) 8...
Scheme 2: Proposed catalytic mechanism of cofactor-independent AlpJ-family oxygenases.
Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98
Graphical Abstract
Scheme 1: General scheme of the borrowing hydrogen (BH) or hydrogen auto-transfer (HA) methodology.
Scheme 2: General scheme for C–N bond formation. A) Traditional cross-couplings with alkyl or aryl halides. B...
Figure 1: Manganese pre-catalysts used for the N-alkylation of amines with alcohols.
Scheme 3: Manganese(I)-pincer complex Mn1 used for the N-alkylation of amines with alcohols and methanol.
Scheme 4: N-Methylation of amines with methanol using Mn2.
Scheme 5: C–N-Bond formation with amines and methanol using PN3P-Mn complex Mn3 reported by Sortais et al. [36]. a...
Scheme 6: Base-assisted synthesis of amines and imines with Mn4. Reaction assisted by A) t-BuOK and B) t-BuON...
Scheme 7: Coupling of alcohols and hydrazine via the HB approach reported by Milstein et al. [38]. aReaction time...
Scheme 8: Proposed mechanism for the coupling of alcohols and hydrazine catalyzed by Mn5.
Scheme 9: Phosphine-free manganese catalyst for N-alkylation of amines with alcohols reported by Balaraman an...
Scheme 10: N-Alkylation of sulfonamides with alcohols.
Scheme 11: Mn–NHC catalyst Mn6 applied for the N-alkylation of amines with alcohols. a3 mol % of Mn6 were used....
Scheme 12: N-Alkylation of amines with primary and secondary alcohols. a80 °C, b100 °C.
Scheme 13: Manganese(III)-porphyrin catalyst for synthesis of tertiary amines.
Scheme 14: Proposed mechanism for the alcohol dehydrogenation with Mn(III)-porphyrin complex Mn7.
Scheme 15: N-Methylation of nitroarenes with methanol using catalyst Mn3.
Scheme 16: Mechanism of manganese-catalyzed methylation of nitroarenes using Mn3 as the catalyst.
Scheme 17: Bidentate manganese complex Mn8 applied for the N-alkylation of primary anilines with alcohols. aOn...
Scheme 18: N-Alkylation of amines with alcohols in the presence of manganese salts and triphenylphosphine as t...
Scheme 19: N-Alkylation of diazo compounds with alcohols using catalyst Mn9.
Scheme 20: Proposed mechanism for the amination of alcohols with diazo compounds catalyzed by catalyst Mn9.
Scheme 21: Mn1 complex-catalyzed synthesis of polyethyleneimine from ethylene glycol and ethylenediamine.
Scheme 22: Bis-triazolylidene-manganese complex Mn10 for the N-alkylation of amines with alcohols.
Figure 2: Manganese complexes applied for C-alkylation reactions of ketones with alcohols.
Scheme 23: General scheme for the C–C bond formation with alcohols and ketones.
Scheme 24: Mn1 complex-catalyzed α-alkylation of ketones with primary alcohols.
Scheme 25: Mechanism for the Mn1-catalyzed alkylation of ketones with alcohols.
Scheme 26: Phosphine-free in situ-generated manganese catalyst for the α-alkylation of ketones with primary al...
Scheme 27: Plausible mechanism for the Mn-catalyzed α-alkylation of ketones with alcohols.
Scheme 28: α-Alkylation of esters, ketones, and amides using alcohols catalyzed by Mn11.
Scheme 29: Mono- and dialkylation of methylene ketones with primary alcohols using the Mn(acac)2/1,10-phenanth...
Scheme 30: Methylation of ketones with methanol and deuterated methanol.
Scheme 31: Methylation of ketones and esters with methanol. a50 mol % of t-BuOK were used, bCD3OD was used ins...
Scheme 32: Alkylation of ketones and secondary alcohols with primary alcohols using Mn4.
Scheme 33: Bidentate manganese-NHC complex Mn6 applied for the synthesis of alkylated ketones using alcohols.
Scheme 34: Mn1-catalyzed synthesis of substituted cycloalkanes by coupling diols and secondary alcohols or ket...
Scheme 35: Proposed mechanism for the synthesis of cycloalkanes via BH method.
Scheme 36: Synthesis of various cycloalkanes from methyl ketones and diols catalyze by Mn13. aReaction time wa...
Scheme 37: N,N-Amine–manganese complex (Mn13)-catalyzed alkylation of ketones with alcohols.
Scheme 38: Naphthyridine‑N‑oxide manganese complex Mn14 applied for the alkylation of ketones with alcohols. a...
Scheme 39: Proposed mechanism of the naphthyridine‑N‑oxide manganese complex (Mn14)-catalyzed alkylation of ke...
Scheme 40: α-Methylation of ketones and indoles with methanol using Mn15.
Scheme 41: α-Alkylation of ketones with primary alcohols using Mn16. aNMR yield.
Figure 3: Manganese complexes used for coupling of secondary and primary alcohols.
Scheme 42: Alkylation of secondary alcohols with primary alcohols catalyzed by phosphine-free catalyst Mn17. a...
Scheme 43: PNN-Manganese complex Mn18 for the alkylation of secondary alcohols with primary alcohols.
Scheme 44: Mechanism for the Mn-pincer catalyzed C-alkylation of secondary alcohols with primary alcohols.
Scheme 45: Upgrading of ethanol with methanol for isobutanol production.
Scheme 46: Mn-Pincer catalyst Mn19 applied for the β-methylation of alcohols with methanol. a2.0 mol % of Mn19...
Scheme 47: Functionalized ketones from primary and secondary alcohols catalyzed by Mn20. aMn20 (5 mol %), NaOH...
Scheme 48: Synthesis of γ-disubstituted alcohols and β-disubstituted ketones through Mn9-catalyzed coupling of...
Scheme 49: Proposed mechanism for the Mn9-catalyzed synthesis of γ-disubstituted alcohols and β-disubstituted ...
Scheme 50: Dehydrogenative coupling of ethylene glycol and primary alcohols catalyzed by Mn4.
Scheme 51: Mn18-cataylzed C-alkylation of unactivated esters and amides with alcohols.
Scheme 52: Alkylation of amides and esters using Mn21.
Scheme 53: α-Alkylation of nitriles with primary alcohols using in situ-generated manganese catalyst.
Scheme 54: Proposed mechanism for the α-alkylation of nitriles with primary alcohols.
Scheme 55: Mn9-catalyzed α-alkylation of nitriles with primary alcohols. a1,4-Dioxane was used as solvent, 24 ...
Figure 4: Manganese complexes used for alkylation of heterocyclic compounds.
Scheme 56: Aminomethylation of aromatic compounds with secondary amines and methanol catalyzed by Mn22.
Scheme 57: Regioselective alkylation of indolines with alcohols catalyzed by Mn9. aMn9 (4 mol %), 48 h.
Scheme 58: Proposed mechanism for the C- and N-alkylation of indolines with alcohols.
Scheme 59: C-Alkylation of methyl N-heteroarenes with primary alcohols catalyzed by Mn1. aTime was 60 h.
Scheme 60: C-Alkylation of oxindoles with secondary alcohols.
Scheme 61: Plausible mechanism for the Mn23-catalyzed C-alkylation of oxindoles with secondary alcohols.
Scheme 62: Synthesis of C-3-alkylated products by coupling alcohols with indoles and aminoalcohols.
Scheme 63: C3-Alkylation of indoles using Mn1.
Scheme 64: C-Methylation of indoles with Mn15 and methanol.
Scheme 65: α-Alkylation of 2-oxindoles with primary and secondary alcohols catalyzed by Mn25. aReaction carrie...
Scheme 66: Dehydrogenative alkylation of indolines with Mn1. aMn1 (5.0 mol %) was used.
Scheme 67: Synthesis of bis(indolyl)methane derivatives from indoles and alcohols catalyzed by Mn26. aMn26 (5....
Scheme 68: One-pot synthesis of pyrimidines via BH.
Scheme 69: Synthesis of pyrroles from alcohols and aminoalcohols using Mn4.
Scheme 70: Synthesis of pyrroles via multicomponent reaction catalyzed by Mn12.
Scheme 71: Friedländer quinoline synthesis using an in situ-generated phosphine-free manganese catalyst.
Scheme 72: Quinoline synthesis using bis-N-heterocyclic carbene-manganese catalyst Mn6.
Scheme 73: Quinoline synthesis using manganese(III)-porphyrin catalyst Mn7.
Scheme 74: Manganese-catalyzed tetrahydroquinoline synthesis via borrowing BH.
Scheme 75: Proposed mechanism for the manganese-catalyzed tetrahydroquinoline synthesis.
Scheme 76: Synthesis of C3-alkylated indoles using Mn24.
Scheme 77: Synthesis of C-3-alkylated indoles using Mn1.
Scheme 78: C–C Bond formation by coupling of alcohols and ylides.
Scheme 79: C-Alkylation of fluorene with alcohols catalyzed by Mn24.
Scheme 80: Proposed mechanism for the C-alkylation of fluorene with alcohols catalyzed by Mn24.
Scheme 81: α-Alkylation of sulfones using Mn-PNN catalyst Mn28.
Beilstein J. Org. Chem. 2024, 20, 1099–1110, doi:10.3762/bjoc.20.97
Graphical Abstract
Figure 1: Neutral, closed-shell resonance forms for pentacene highlighting Clar aromatic sextets (see [1]) and t...
Figure 2: The only neutral, closed-shell resonance form for 5-ring isotetracenofuran with its highly delocali...
Figure 3: DFT calculated HOMO–LUMO gaps of acenes and isoacenofurans performed at the B3LYP/6-311+G(d,p)//B3L...
Figure 4: A structural rendering of 1,3-dimesitylisobenzofuran showing the requirement for non-planar mesityl...
Scheme 1: Synthesis of 1,3-diarylisobenzofurans 3 and 23.
Figure 5: UV–vis (top) and fluorescence (middle) spectra for 10−6 M solutions of 1,3-diarylisobenzofurans 2, 3...
Figure 6: Calculated HOMO and LUMO orbitals for parent isobenzofuran (1) and 1,3-diarylisobenzofuran derivati...
Figure 7: UV–vis spectra calculated for 1,3-diarylisobenzofuran derivatives 1, 2, 3, 23, 24 and 25 using a DF...
Figure 8: UV–vis spectra for the reactions of 2 (top) and 3 (bottom) with a 7000-fold excess of DMAD in CH2Cl2...
Scheme 2: Reactions between 1,3-diarylisobenzofurans 2, 3 and 23 and DMAD to produce Diels–Alder adducts 26, ...
Scheme 3: Synthesis of 1,3-dimesitylisobenzofuran (3).
Scheme 4: Synthesis of 1,2-phenylenebis(mesitylmethanone) (21).
Scheme 5: Synthesis of 1,2-phenylenebis((2,4,6-triethylphenyl)methanone) (22).
Scheme 6: Synthesis of 1,3-bis(2,4,6-triethylphenyl)isobenzofuran (23).
Scheme 7: Synthesis of dimethyl 1,4-diphenyl-1,4-dihydro-1,4-epoxynaphthalene-2,3-dicarboxylate (26).
Scheme 8: Synthesis of dimethyl 1,4-dimesityl-1,4-dihydro-1,4-epoxynaphthalene-2,3-dicarboxylate (27).
Beilstein J. Org. Chem. 2024, 20, 1076–1087, doi:10.3762/bjoc.20.95
Graphical Abstract
Figure 1: Comparison between the light-initiated radical halogenation of toluene (right), and the Ar-SE bromi...
Figure 2: Toluene halogenation mediated by NBS in absence (left) or exposed to light (right).
Figure 3: Scifinder® reaction hits for the structure “as drawn” (January 2024).
Figure 4: Yields obtained in the preparation of aryl-cored halides.
Beilstein J. Org. Chem. 2024, 20, 1053–1068, doi:10.3762/bjoc.20.93
Graphical Abstract
Figure 1: (a) Previously studied BBD-based photoswitches, (b) recently reported protocol to synthesize a BBD ...
Figure 2: Energy storage capacities and barrier for back conversion of the photoproduct to the diene in the g...
Figure 3: (a) Optimized geometry along with the important geometrical parameters of the TS obtained for the t...
Figure 4: Photophysical properties of the studied BBD photoswitches with elongated unsaturated bridges. (a) O...
Figure 5: Effect of solvation on the thermochemical properties of the studied BBD photoswitches considering t...
Figure 6: Effect of solvation on the photophysical properties of the studied BBD photoswitches. (a) Optical s...
Figure 7: The undesired degradation competing the thermal back conversion of the photoproduct. (a) The therma...
Figure 8: Relative energy profiles for the conversion of the photoproducts into the parent dienes and undesir...
Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92
Graphical Abstract
Figure 1: Chemical structures of H-bonding N-heteroacenes synthesized by Miao et al. and Bunz et al. (a) [22,23]. Pr...
Scheme 1: Synthesis of dicyanopyrazinoquinoxaline derivatives 1a–7a.
Scheme 2: Synthesis of bis-alkoxy-substituted π-conjugated phenanthrolines 16a, 16b, 16c, and 16d.
Scheme 3: An alternative synthetic route to access 7a.
Scheme 4: Synthesis of DPQDs 1b–7b from their corresponding DCPQs 1a–7a. *THF/H2O/1,4-dioxane (4:5:1). **in s...
Figure 2: TGA of 1a–6a (a) and 1b–7b (b) obtained at 10 °C/min under nitrogen.
Figure 3: Absorption spectra (20 μM) for a) DCPQs 1a–6a and b) DPQDs 1b–7b in dimethyl sulfoxide.
Figure 4: Calculated HOMO (below) and LUMO (above) energies by DFT analysis (B3LYP/6-31+G* level of theory), ...
Figure 5: Calculated HOMO (below) and LUMO (above) energies by DFT analysis (B3LYP/6-31+G* level of theory), ...
Figure 6: Asymmetric unit of DPQD 2b with important bond lengths highlighted (a). Torsion angles of 4.33° and...
Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87
Graphical Abstract
Scheme 1: Pd(0)-catalyzed domino C,N-coupling/carbonylation/Suzuki coupling reaction for the synthesis of 2-a...
Scheme 2: Pd(0)-catalyzed single isonitrile insertion: synthesis of 1-(3-amino)-1H-indol-2-yl)-1-ketones.
Scheme 3: Pd(0)-catalyzed gas-free carbonylation of 2-alkynylanilines to 1-(1H-indol-1-yl)-2-arylethan-1-ones....
Scheme 4: Pd(II)-catalyzed heterocyclization/alkoxycarbonylation of 2-alkynylaniline imines.
Scheme 5: Pd(II)-catalyzed heterocyclization/alkoxycarbonylation of 2-alkynylanilines to N-substituted indole...
Scheme 6: Synthesis of indol-2-acetic esters by Pd(II)-catalyzed carbonylation of 1-(2-aminoaryl)-2-yn-1-ols.
Scheme 7: Pd(II)-catalyzed carbonylative double cyclization of suitably functionalized 2-alkynylanilines to 3...
Scheme 8: Indole synthesis by deoxygenation reactions of nitro compounds reported by Cenini et al. [21].
Scheme 9: Indole synthesis by reduction of nitro compounds: approach reported by Watanabe et al. [22].
Scheme 10: Indole synthesis from o-nitrostyrene compounds as reported by Söderberg and co-workers [23].
Scheme 11: Synthesis of fused indoles (top) and natural indoles present in two species of European Basidiomyce...
Scheme 12: Synthesis of 1,2-dihydro-4(3H)-carbazolones through N-heteroannulation of functionalized 2-nitrosty...
Scheme 13: Synthesis of indoles from o-nitrostyrenes by using Pd(OAc)2 and Pd(tfa)2 in conjunction with bident...
Scheme 14: Synthesis of substituted 3-alkoxyindoles via palladium-catalyzed reductive N-heteroannulation.
Scheme 15: Synthesis of 3-arylindoles by palladium-catalyzed C–H bond amination via reduction of nitroalkenes.
Scheme 16: Synthesis of 2,2′-bi-1H-indoles, 2,3′-bi-1H-indoles, 3,3′-bi-1H-indoles, indolo[3,2-b]indoles, indo...
Scheme 17: Pd-catalyzed reductive cyclization of 1,2-bis(2-nitrophenyl)ethene and 1,1-bis(2-nitrophenyl)ethene...
Scheme 18: Flow synthesis of 2-substituted indoles by reductive carbonylation.
Scheme 19: Pd-catalyzed synthesis of variously substituted 3H-indoles from nitrostyrenes by using Mo(CO)6 as C...
Scheme 20: Synthesis of indoles from substituted 2-nitrostyrenes (top) and ω-nitrostyrenes (bottom) via reduct...
Scheme 21: Synthesis of indoles from substituted 2-nitrostyrenes with formic acid as CO source.
Scheme 22: Ni-catalyzed carbonylative cyclization of 2-nitroalkynes and aryl iodides (top) and the Ni-catalyze...
Scheme 23: Mechanism of the Ni-catalyzed carbonylative cyclization of 2-nitroalkynes and aryl iodides (top) an...
Scheme 24: Route to indole derivatives through Rh-catalyzed benzannulation of heteroaryl propargylic esters fa...
Scheme 25: Pd-catalyzed cyclization of 2-(2-haloaryl)indoles reported by Yoo and co-workers [54], Guo and co-worke...
Scheme 26: Approach for the synthesis of 6H-isoindolo[2,1-a]indol-6-ones reported by Huang and co-workers [57].
Scheme 27: Zhou group’s method for the synthesis of 6H-isoindolo[2,1-a]indol-6-ones.
Scheme 28: Synthesis of 6H-isoindolo[2,1-a]indol-6-ones from o-1,2-dibromobenzene and indole derivatives by us...
Scheme 29: Pd(OAc)2-catalyzed Heck cyclization of 2-(2-bromophenyl)-1-alkyl-1H-indoles reported by Guo et al. [55]....
Scheme 30: Synthesis of indolo[1,2-a]quinoxalinone derivatives through Pd/Cu co-catalyzed carbonylative cycliz...
Scheme 31: Pd-catalyzed carbonylative cyclization of o-indolylarylamines and N-monosubstituted o-indolylarylam...
Scheme 32: Pd-catalyzed diasteroselective carbonylative cyclodearomatization of N-(2-bromobenzoyl)indoles with...
Scheme 33: Pd(0)-catalyzed synthesis of CO-linked heterocyclic scaffolds from alkene-indole derivatives and 2-...
Scheme 34: Proposed mechanism for the Pd(0)-catalyzed synthesis of CO-linked heterocyclic scaffolds.
Scheme 35: Pd-catalyzed C–H and N–H alkoxycarbonylation of indole derivatives to indole-3-carboxylates and ind...
Scheme 36: Rh-catalyzed C–H alcoxycarbonylation of indole derivatives to indole-3-carboxylates reported by Li ...
Scheme 37: Pd-catalyzed C–H alkoxycarbonylation of indole derivatives with alcohols and phenols to indole-3-ca...
Scheme 38: Synthesis of N-methylindole-3-carboxylates from N-methylindoles and phenols through metal-catalyst-...
Scheme 39: Synthesis of indol-3-α-ketoamides (top) and indol-3-amides (bottom) via direct double- and monoamin...
Scheme 40: The direct Sonogashira carbonylation coupling reaction of indoles and alkynes via Pd/CuI catalysis ...
Scheme 41: Synthesis of indole-3-yl aryl ketones reported by Zhao and co-workers [73] (path a) and Zhang and co-wo...
Scheme 42: Pd-catalyzed carbonylative synthesis of BIMs from aryl iodides and N-substituted and NH-free indole...
Scheme 43: Cu-catalyzed direct double-carbonylation and monocarbonylation of indoles and alcohols with hexaket...
Scheme 44: Rh-catalyzed direct C–H alkoxycarbonylation of indoles to indole-2-carboxylates [79] (top) and Co-catal...
Scheme 45: Pd-catalyzed carbonylation of NH free-haloindoles.
Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72
Graphical Abstract
Scheme 1: Classes of hydrochlorination reactions discussed in this review.
Figure 1: Mayr’s nucleophilicity parameters for several alkenes. References for each compound can be consulte...
Figure 2: Hydride affinities relating to the reactivity of the corresponding alkene towards hydrochlorination....
Scheme 2: Distinction of polar hydrochlorination reactions.
Scheme 3: Reactions of styrenes with HCl gas or HCl solutions.
Figure 3: Normal temperature dependence for the hydrochlorination of (Z)-but-2-ene.
Figure 4: Pentane slows down the hydrochlorination of 11.
Scheme 4: Recently reported hydrochlorinations of styrenes with HCl gas or HCl solutions.
Scheme 5: Hydrochlorination reactions with di- and trisubstituted alkenes.
Scheme 6: Hydrochlorination of fatty acids with liquified HCl.
Scheme 7: Hydrochlorination with HCl/DMPU solutions.
Scheme 8: Hydrochlorination with HCl generated from EtOH and AcCl.
Scheme 9: Hydrochlorination with HCl generated from H2O and TMSCl.
Scheme 10: Regioisomeric mixtures of chlorooctanes as a result of hydride shifts.
Scheme 11: Regioisomeric mixtures of products as a result of methyl shifts.
Scheme 12: Applications of the Kropp procedure on a preparative scale.
Scheme 13: Curious example of polar anti-Markovnikov hydrochlorination.
Scheme 14: Unexpected and expected hydrochlorinations with AlCl3.
Figure 5: Ex situ-generated HCl gas and in situ application for the hydrochlorination of activated alkenes (*...
Scheme 15: HCl generated by Grob fragmentation of 92.
Scheme 16: Formation of chlorophosphonium complex 104 and the reaction thereof with H2O.
Scheme 17: Snyder’s hydrochlorination with stoichiometric amounts of complex 104 or 108.
Scheme 18: In situ generation of HCl by mixing of MsOH with CaCl2.
Scheme 19: First hydrochlorination of alkenes using hydrochloric acid.
Scheme 20: Visible-light-promoted hydrochlorination.
Scheme 21: Silica gel-promoted hydrochlorination of alkenes with hydrochloric acid.
Scheme 22: Hydrochlorination with hydrochloric acid promoted by acetic acid or iron trichloride.
Figure 6: Metal hydride hydrogen atom transfer reactions vs cationic reactions; BDE (bond-dissociation energy...
Scheme 23: Carreira’s first report on radical hydrochlorinations of alkenes.
Figure 7: Mechanism for the cobalt hydride hydrogen atom transfer reaction reported by Carreira.
Scheme 24: Radical “hydrogenation” of alkenes; competing chlorination reactions.
Scheme 25: Bogers iron-catalyzed radical hydrochlorination.
Scheme 26: Hydrochlorination instead of hydrogenation product.
Scheme 27: Optimization of the Boger protocol by researchers from Merck [88,89].
Figure 8: Proposed mechanism for anti-Markovnikov hydrochlorination by Nicewicz.
Scheme 28: anti-Markovnikov hydrochlorinations as reported by Nicewicz.
Figure 9: Mechanism for anti-Markovnikov hydrochlorination according to Ritter.
Scheme 29: anti-Markovnikov hydrochlorinations as reported by Nicewicz; rr (regioisomeric ratio) corresponds t...
Scheme 30: anti-Markovnikov hydrochlorinations as reported by Liu.
Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68
Graphical Abstract
Figure 1: Principal structure of crocin and crocetin derivatives, including common substituents of the crocet...
Figure 2: The pharmacological activity and mechanisms of action of crocins.
Figure 3: Crocin biosynthetic pathways in C. sativus and G. jasminoides. Enzyme abbreviations are as follows:...