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Search for "Suzuki–Miyaura coupling" in Full Text gives 91 result(s) in Beilstein Journal of Organic Chemistry.
Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects
- Shivani Gulati,
- Stephy Elza John and
- Nagula Shankaraiah
Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71
- azepinone 22 and exemplified a modified Ugi reaction (four-component reaction). The aldehyde and acid component of the Ugi reaction was functionalized on the same biaryl ring employing a Suzuki–Miyaura coupling. The authors advocated the use of microwave as it consistently increased the yield from 49% to 82
Graphical Abstract
Figure 1: Marketed drugs with acridine moiety.
Scheme 1: Synthesis of 4-arylacridinediones.
Scheme 2: Proposed mechanism for acridinedione synthesis.
Scheme 3: Synthesis of tetrahydrodibenzoacridinones.
Scheme 4: Synthesis of naphthoacridines.
Scheme 5: Plausible mechanism for naphthoacridines.
Figure 2: Benzoazepines based potent molecules.
Scheme 6: Synthesis of azepinone.
Scheme 7: Proposed mechanism for azepinone formation.
Scheme 8: Synthesis of benzoazulenen-1-one derivatives.
Scheme 9: Proposed mechanism for benzoazulene-1-one synthesis.
Figure 3: Indole-containing pharmacologically active molecules.
Scheme 10: Synthesis of functionalized indoles.
Scheme 11: Plausible mechanism for the synthesis of functionalized indoles.
Scheme 12: Synthesis of spirooxindoles.
Scheme 13: Synthesis of substituted spirooxindoles.
Scheme 14: Plausible mechanism for the synthesis of substituted spirooxindoles.
Scheme 15: Synthesis of pyrrolidinyl spirooxindoles.
Scheme 16: Proposed mechanism for pyrrolidinyl spirooxindoles.
Figure 4: Pyran-containing biologically active molecules.
Scheme 17: Synthesis of functionalized benzopyrans.
Scheme 18: Plausible mechanism for synthesis of benzopyran.
Scheme 19: Synthesis of indoline-spiro-fused pyran derivatives.
Scheme 20: Proposed mechanism for indoline-spiro-fused pyran.
Scheme 21: Synthesis of substituted naphthopyrans.
Figure 5: Marketed drugs with pyrrole ring.
Scheme 22: Synthesis of tetra-substituted pyrroles.
Scheme 23: Mechanism for silica-supported PPA-SiO2-catalyzed pyrrole synthesis.
Scheme 24: Synthesis of pyrrolo[1,10]-phenanthrolines.
Scheme 25: Proposed mechanism for pyrrolo[1,10]-phenanthrolines.
Figure 6: Marketed drugs and molecules containing pyrimidine and pyrimidinones skeletons.
Scheme 26: MWA-MCR pyrimidinone synthesis.
Scheme 27: Two proposed mechanisms for pyrimidinone synthesis.
Scheme 28: MWA multicomponent synthesis of dihydropyrimidinones.
Scheme 29: Proposed mechanism for dihydropyrimidinones.
Figure 7: Biologically active fused pyrimidines.
Scheme 30: MWA- MCR for the synthesis of pyrrolo[2,3-d]pyrimidines.
Scheme 31: Proposed mechanism for pyrrolo[2,3-d]pyrimidines.
Scheme 32: Synthesis of substituted pyrrolo[2,3-d]pyrimidine-2,4-diones.
Scheme 33: Probable pathway for pyrrolo[2,3-d]pyrimidine-2,4-diones.
Scheme 34: Synthesis of pyridopyrimidines.
Scheme 35: Plausible mechanism for the synthesis of pyridopyrimidines.
Scheme 36: Synthesis of dihydropyridopyrimidine and dihydropyrazolopyridine.
Scheme 37: Proposed mechanism for the formation of dihydropyridopyrimidine.
Scheme 38: Synthesis of thiopyrano[4,3-d]pyrimidines.
Scheme 39: Plausible mechanism for the synthesis of thiopyrano[4,3-d]pyrimidines.
Scheme 40: Synthesis of decorated imidazopyrimidines.
Scheme 41: Proposed mechanism for imidazopyrimidine synthesis.
Figure 8: Pharmacologically active molecules containing purine bases.
Scheme 42: Synthesis of aza-adenines.
Scheme 43: Synthesis of 5-aza-7-deazapurines.
Scheme 44: Proposed mechanism for deazapurines synthesis.
Figure 9: Biologically active molecules containing pyridine moiety.
Scheme 45: Synthesis of steroidal pyridines.
Scheme 46: Proposed mechanism for steroidal pyridine.
Scheme 47: Synthesis of N-alkylated 2-pyridones.
Scheme 48: Two possible mechanisms for pyridone synthesis.
Scheme 49: Synthesis of pyridone derivatives.
Scheme 50: Postulated mechanism for synthesis of pyridone.
Figure 10: Biologically active fused pyridines.
Scheme 51: Benzimidazole-imidazo[1,2-a]pyridines synthesis.
Scheme 52: Mechanism for the synthesis of benzimidazole-imidazo[1,2-a]pyridines.
Scheme 53: Synthesis of pyrazolo[3,4-b]pyridine-5-spirocycloalkanedione derivatives.
Scheme 54: Proposed mechanism for spiro-pyridines.
Scheme 55: Functionalized macrocyclane-fused pyrazolo[3,4-b]pyridine derivatives.
Scheme 56: Mechanism postulated for macrocyclane-fused pyrazolo[3,4-b]pyridine.
Scheme 57: Generation of pyrazolo[3,4-b]pyridines.
Scheme 58: Proposed mechanism for the synthesis of pyrazolo[3,4-b]pyridines.
Scheme 59: Proposed mechanism for the synthesis of azepinoindole.
Figure 11: Pharmaceutically important molecules with quinoline moiety.
Scheme 60: Povarov-mediated quinoline synthesis.
Scheme 61: Proposed mechanism for Povarov reaction.
Scheme 62: Synthesis of pyrazoloquinoline.
Scheme 63: Plausible mechanism for pyrazoloquinoline synthesis.
Figure 12: Quinazolinones as pharmacologically significant scaffolds.
Scheme 64: Four-component reaction for dihydroquinazolinone.
Scheme 65: Proposed mechanism for dihydroquinazolinones.
Scheme 66: Synthesis purine quinazolinone and PI3K-δ inhibitor.
Scheme 67: Synthesis of fused benzothiazolo/benzoimidazoloquinazolinones.
Scheme 68: Proposed mechanism for fused benzothiazolo/benzoimidazoloquinazolinones.
Scheme 69: On-water reaction for synthesis of thiazoloquinazolinone.
Scheme 70: Proposed mechanism for the thiazoloquinazolinone synthesis.
Scheme 71: β-Cyclodextrin-mediated synthesis of indoloquinazolinediones.
Scheme 72: Proposed mechanism for synthesis of indoloquinazolinediones.
Figure 13: Triazoles-containing marketted drugs and pharmacologically active molecules.
Scheme 73: Cu(I) DAPTA-catalyzed 1,2,3-triazole formation.
Scheme 74: Mechanism for Cu(I) DAPTA-catalyzed triazole formation.
Scheme 75: Synthesis of β-hydroxy-1,2,3-triazole.
Scheme 76: Proposed mechanism for synthesis of β-hydroxy-1,2,3-triazoles.
Scheme 77: Synthesis of bis-1,2,4-triazoles.
Scheme 78: Proposed mechanism for bis-1,2,4-triazoles synthesis.
Figure 14: Thiazole containing drugs.
Scheme 79: Synthesis of a substituted thiazole ring.
Scheme 80: Synthesis of pyrazolothiazoles.
Figure 15: Chromene containing drugs.
Scheme 81: Magnetic nanocatalyst-mediated aminochromene synthesis.
Scheme 82: Proposed mechanism for the synthesis of chromenes.
Total synthesis of pyrrolo[2,3-c]quinoline alkaloid: trigonoine B
- Takashi Nishiyama,
- Erina Hamada,
- Daishi Ishii,
- Yuuto Kihara,
- Nanase Choshi,
- Natsumi Nakanishi,
- Mari Murakami,
- Kimiko Taninaka,
- Noriyuki Hatae and
- Tominari Choshi
Beilstein J. Org. Chem. 2021, 17, 730–736, doi:10.3762/bjoc.17.62
- -azahexatriene system. Lastly, it was proposed that the carbodiimide 10 could be derived from urea 11. Therefore, we investigated the electrocyclization of a pyrrol-3-ylbenzene containing a carbodiimide moiety. First, 2-(pyrrol-3-yl)aniline 14 was synthesized by a Suzuki–Miyaura coupling reaction of 2
- -iodo-5-methoxyaniline (24), was synthesized according to the procedure previously reported by Wetzel and co-workers [31]. The Suzuki–Miyaura coupling of 2-iodoaniline derivative 24 and pyrrole-3-boronic acid pinacol ester 13 was carried out in the presence of Pd(OAc)2 and SPhos, followed by the
Graphical Abstract
Figure 1: Natural products possessing the pyrrolo[2,3-c]quinoline skeleton.
Scheme 1: Total synthesis of marinoquinolines and the failure of the introduction of a tetrahydroquinoline mo...
Scheme 2: Retrosynthetic analysis of the pyrrolo[2,3-c]quinoline ring construction.
Scheme 3: Synthesis of N-substituted 4-aminopyrrolo[3,2-c]quinoline 18.
Scheme 4: Synthesis of the tetrahydroquinoline moiety through cycloamination.
Scheme 5: Synthesis of trigonoine B (1).
Helicene synthesis by Brønsted acid-catalyzed cycloaromatization in HFIP [(CF3)2CHOH]
- Takeshi Fujita,
- Noriaki Shoji,
- Nao Yoshikawa and
- Junji Ichikawa
Beilstein J. Org. Chem. 2021, 17, 396–403, doi:10.3762/bjoc.17.35
- bisacetal precursors, which were readily prepared through C–C bond formation by Suzuki–Miyaura coupling. This cyclization was efficiently realized by a catalytic amount of trifluoromethanesulfonic acid (TfOH) in a cation-stabilizing solvent, 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP), which readily allowed
- central aromatic ring (Ar1) (Scheme 3, route b). The teraryl structures were constructed by the formation of two C–C bonds via tandem Suzuki–Miyaura coupling of two terminal (Ar2) and central (Ar1) arenes. It is noted that dihalogenated arenes were adopted as components for the central aromatic ring (Ar1
- , and heterohelicenes. Results and Discussion Carbohelicenes such as [5]helicene (1a) and [6]helicene (1b) were synthesized via Suzuki–Miyaura coupling of readily available dihalogenated arenes 2 with phenylboronic acid ester 3 bearing a (1,3-dioxolan-2-yl)methyl group [29], followed by triflic acid
Graphical Abstract
Scheme 1: Conventional methods for the synthesis of helicenes.
Scheme 2: Brønsted acid-catalyzed cycloaromatization of biaryls bearing an acetal moiety.
Scheme 3: Two strategies for the helicene synthesis via Suzuki–Miyaura coupling/cycloaromatization sequence.
Scheme 4: Synthesis of (a) [5]helicene and (b) [6]helicene.
Scheme 5: Synthesis of helicenes with double helical structures.
Scheme 6: Synthesis of hetero[4]-, [5]-, and [6]helicenes.
Progress in the total synthesis of inthomycins
- Bidyut Kumar Senapati
Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7
- between vinyl bromide (Z,Z)-(+)-145a and (E)-vinylstannane 24 [43] proceeded without significant isomerization to give (4Z,6Z,8E)-triene (+)-146a, a subunit of inthomycin A ((+)-1). Meanwhile, the Suzuki–Miyaura coupling of vinylboronate (Z,E)-(+)-145b with the known (E)-oxazole iodide 48 [43] was
Graphical Abstract
Figure 1: The inthomycins A–C (1–3) and structurally closely related compounds.
Figure 2: Syntheses of inthomycins A–C (1–3).
Scheme 1: The first total synthesis of racemic inthomycin A (rac)-1 by Whiting.
Scheme 2: Moloney’s synthesis of the phenyl analogue of inthomycin C ((rac)-3).
Scheme 3: Moloney’s synthesis of phenyl analogues of inthomycins A (rac-1) and B (rac-2).
Scheme 4: The first total synthesis of inthomycin B (+)-2 by R. J. K. Taylor.
Scheme 5: R. J. K. Taylor’s total synthesis of racemic inthomycin A (rac)-1.
Scheme 6: The first total synthesis of inthomycin C ((+)-3) by R. J. K. Taylor.
Scheme 7: The first total synthesis of naturally occurring inthomycin C ((–)-3) by Ryu et al.
Scheme 8: Preparation of E,E-iododiene (+)-84 and Z,E- iododiene 85a.
Scheme 9: Hatakeyama’s total synthesis of inthomycin A (+)-1 and inthomycin B (+)-2.
Scheme 10: Hatakeyama’s total synthesis of inthomycin C ((–)-3).
Scheme 11: Maulide’s formal synthesis of racemic inthomycin C ((rac)-3).
Scheme 12: Hale’s synthesis of dienylstannane (+)-69 and enyne (+)-82b intermediates.
Scheme 13: Hale’s total synthesis of inthomycin C ((+)-3).
Scheme 14: Hale and Hatakeyama’s resynthesis of (3R)-inthomycin C (−)-3 Mosher esters.
Scheme 15: Reddy’s formal syntheses of inthomycin C (+)-3 and inthomycin C ((−)-3).
Scheme 16: Synthesis of the cross-metathesis precursors (rac)-118 and 121.
Scheme 17: Donohoe’s total synthesis of inthomycin C ((−)-3).
Scheme 18: Synthesis of dienylboronic ester (E,E)-128.
Scheme 19: Synthesis of the alkenyl iodides (Z)- and (E)-130.
Scheme 20: Burton’s total synthesis of inthomycin B ((+)-2).
Scheme 21: Burton’s total synthesis of inthomycin C ((−)-3).
Scheme 22: Burton’s total synthesis of inthomycin A ((+)-1).
Scheme 23: Synthesis of common intermediate (Z)-(+)-143a.
Scheme 24: Synthesis of (Z)-and (E)-selective fragments (+)-145a–c.
Scheme 25: Kim’s total synthesis of inthomycins A (+)-1 and B (+)-2.
Scheme 26: Completion of total synthesis of inthomycin C ((–)-3) by Kim.
Naphthalonitriles featuring efficient emission in solution and in the solid state
- Sidharth Thulaseedharan Nair Sailaja,
- Iván Maisuls,
- Jutta Kösters,
- Alexander Hepp,
- Andreas Faust,
- Jens Voskuhl and
- Cristian A. Strassert
Beilstein J. Org. Chem. 2020, 16, 2960–2970, doi:10.3762/bjoc.16.246
- –Miyaura coupling reaction starting from 6,7-dibromo-2,3-dicyanonaphthalene, which was prepared according to the literature [45] (Scheme 2). The compounds with the substituents R = H [46] and t-Bu [47] are already known and were herein investigated for comparative purpose. The standard reaction conditions
- exhibit weak emission in the inner cell, and ACQgens show weak emission in the outer cell [44]. Results and Discussion Synthesis and structural characterization In this contribution, six different p-phenyl-2,3-disubstituted-6,7-diphenylnaphthalenes with variable moieties were synthesized by the Suzuki
Graphical Abstract
Scheme 1: A) Structures of the six investigated 2,3-disubstituted-6,7-diphenylnaphthalene derivatives with va...
Scheme 2: Synthesis of p-phenyl-6,7-disubstituted naphthalene-2,3-dicarbonitrile.
Figure 1: Molecular structure in the crystal of Me as obtained by X-ray diffractometric analysis. Thermal dis...
Figure 2: A) Intermolecular CH…π interactions for compound Me. B) Weak intermolecular π–π stacking interactio...
Figure 3: Normalized absorption spectra of the evaluated compounds in fluid THF at rt. All solutions were opt...
Figure 4: Normalized emission spectra of the evaluated compounds in fluid THF at rt (left) and in a frozen gl...
Figure 5: A) Photographs of H at different THF/H2O ratios under UV excitation (λ = 365 nm). B) Photoluminesce...
The biomimetic synthesis of balsaminone A and ellagic acid via oxidative dimerization
- Sharna-kay Daley and
- Nadale Downer-Riley
Beilstein J. Org. Chem. 2020, 16, 2026–2031, doi:10.3762/bjoc.16.169
- Ullman coupling, Suzuki–Miyaura coupling and Stille coupling have dominated the field for the synthesis of biaryls [1][4]. Throughout the years, the exploration of oxidative dimerization reactions of electron-rich aromatic compounds, such as thiophenes, anilines and alkoxyarenes, in an attempt to
Graphical Abstract
Figure 1: Selected natural products synthesized via oxidative dimerization.
Scheme 1: Proposed biosynthesis of balsaminone A (4) [19].
Scheme 2: Proposed biosynthesis of ellagic acid (5) [20].
Scheme 3: Previous syntheses of balsaminone A (4) [22] and ellagic acid (5) [23].
Scheme 4: Attempted synthesis of the biomimetic precursor 9. [O]: Act-C, K3[Fe(CN)6], or p-benzoquinone.
Scheme 5: Biomimetic synthesis of balsaminone A (4).
Scheme 6: Concise and efficient biomimetic synthesis of ellagic acid (5).
Syntheses of spliceostatins and thailanstatins: a review
- William A. Donaldson
Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166
- . The removal of the silyl protecting group and hydrolysis of the methyl ester afforded the carboxylic acid 108. A subsequently attempted Suzuki–Miyaura coupling of 108 with vinyl boronates was described as “capricious”, and thus the acid was esterified with the tert-butyl donor reagent 109 to afford
- utilized the sequential application of a cross-metathesis and a Suzuki–Miyaura coupling in the syntheses of thailanstatin A and B (7 and 5) and spliceostatin D (9, Scheme 24) [24][25]. To this end, the methylhydrazinolysis of the phthalimide 39 and the amide formation with 12c yielded 121. The cross
- -metathesis of 121 with a five-fold excess of isopropenylboronic acid pinacol ester afforded the lynchpin vinylborane 130. A Pd-catalyzed Suzuki–Miyaura coupling of 130 with the vinyl iodide 110, 111, or 112 gave the tert-butyl ester 131, 132, or 133 in a moderate yield (42–63%). The hydrolysis of the tert
Graphical Abstract
Figure 1: Structures of spliceostatins/thailanstatins.
Scheme 1: Synthetic routes to protected (2Z,4S)-4-hydroxy-2-butenoic acid fragments.
Scheme 2: Kitahara synthesis of the (all-cis)-2,3,5,6-tetrasubstituted tetrahydropyran.
Scheme 3: Koide synthesis of (all-cis)-2,3,5,6-tetrasubstituted tetrahydropyran.
Scheme 4: Nicolaou synthesis of the (all-cis)-2,3,5,6-tetrasubstituted tetrahydropyran.
Scheme 5: Jacobsen synthesis of the (all-cis)-2,3,5,6-tetrasubstituted tetrahydropyran.
Scheme 6: Unproductive attempt to generate the (all-cis)-tetrahydropyranone 50.
Scheme 7: Ghosh synthesis of the C-7–C-14 (all-cis)-tetrahydropyran segment.
Scheme 8: Ghosh’s alternative route to the (all-cis)-tetrahydropyranone 50.
Scheme 9: Alternative synthesis of the dihydro-3-pyrone 58.
Scheme 10: Kitahara’s 1st-generation synthesis of the C-1–C-6 fragment of FR901464 (1).
Scheme 11: Kitahara 1st-generation synthesis of the C-1–C-6 fragment of FR901464 (1).
Scheme 12: Nimura/Arisawa synthesis of the C-1-phenyl segment.
Scheme 13: Ghosh synthesis of the C-1–C-6 fragment of FR901464 (1) from (R)-glyceraldehyde acetonide.
Scheme 14: Jacobsen synthesis of the C-1–C-7 segment of FR901464 (1).
Scheme 15: Koide synthesis of the C-1–C-7 segment of FR901464 (1).
Scheme 16: Ghosh synthesis of the C-1–C-5 segment 102 of thailanstatin A (7).
Scheme 17: Nicolaou synthesis of the C-1–C-9 segments of spliceostatin D (9) and thailanstatins A (7) and B (5...
Scheme 18: Ghosh synthesis of the C-1–C-6 segment 115 of spliceostatin E (10).
Scheme 19: Fragment coupling via Wittig and modified Julia olefinations by Kitahara.
Scheme 20: Fragment coupling via cross-metathesis by Koide.
Scheme 21: The Ghosh synthesis of spliceostatin A (4), FR901464 (1), spliceostatin E (10), and thailanstatin m...
Scheme 22: Arisawa synthesis of a C-1-phenyl analog of FR901464 (1).
Scheme 23: Jacobsen fragment coupling by a Pd-catalyzed Negishi coupling.
Scheme 24: Nicolaou syntheses of thailanstatin A and B (7 and 5) and spliceostatin D (9) via a Pd-catalyzed Su...
Scheme 25: The Ghosh synthesis of spliceostatin G (11) via Suzuki–Miyaura coupling.
Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones
- Valeria Nori,
- Antonio Arcadi,
- Armando Carlone,
- Fabio Marinelli and
- Marco Chiarini
Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95
- (Te), Italy 10.3762/bjoc.16.95 Abstract Cascade cyclocarbopalladation of the readily available aryl/alkyl-substituted propargylic amides containing an aryl iodide moiety, followed by Suzuki–Miyaura coupling with arylboronic acids, allowed an efficient regio- and stereoselective synthesis of
- 4 and 6 was unambiguously confirmed by NMR spectroscopy [43]. Conclusion In conclusion, we have demonstrated that cascade cyclocarbopalladations of the readily available aryl/alkyl-substituted N-propargyl-2-iodobenzamides 2 followed by Suzuki–Miyaura coupling reactions with arylboronic acids, in the
Graphical Abstract
Scheme 1: Planned approach to tetrasubstituted-4-methylene-3,4-dihydroisoquinolin-1(2H)-ones 4 and 6.
Scheme 2: Preparation of the starting N-propargyl-2-iodobenzamides 2.
Scheme 3: Substrate scope of the reaction of N-propargyl-2-iodobenzamide 2a with arylboronic acids 3b–i.
Scheme 4: Substrate scope of the reaction of N-propargyl-2-iodobenzamides 2c–f with arylboronic acids 3a–c/j.
Scheme 5: Reaction of N-propargyl-2-iodobenzamides 2b,f with the 2-alkynyltrifluoroacetanilides 5a–c.
Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions for the synthesis of chiral biaryl compounds with a large steric substituent at the 2-position
- Yongsu Li,
- Bendu Pan,
- Xuefeng He,
- Wang Xia,
- Yaqi Zhang,
- Hao Liang,
- Chitreddy V. Subba Reddy,
- Rihui Cao and
- Liqin Qiu
Beilstein J. Org. Chem. 2020, 16, 966–973, doi:10.3762/bjoc.16.85
- structure (Scheme 4). Conclusion In summary, a Pd-catalyzed asymmetric Suzuki–Miyaura coupling of 3-methyl-2-bromophenylamides or 3-methyl-2-bromo-1-nitrobenzene and 1-naphthaleneboronic acids has been successfully developed and the corresponding axially chiral biaryl compounds were obtained in very high
- by column chromatography to obtain the desired products. General procedure for the asymmetric Suzuki–Miyaura coupling In a glovebox, an oven-dried sealing tube (15 mL) was charged with bromoarylamides (0.2 mmol, 1.0 equiv), Pd2(dba)3 (0.005 mmol, 5 mol % Pd), ligand L7 (0.012 mmol, 6 mol
- silica gel. The enantiomeric excess value of the product was determined by HPLC by using an AD-H, OD-H or IA-3 column. (R)-MeO-MOP and our ligands. Asymmetric Suzuki–Miyaura coupling. Reaction conditions: 1 equiv N-aryl-bromoaryl compounds, 2 equiv arylboronic acids, 5 mol % Pd, 6 mol % ligand, 3 equiv
Graphical Abstract
Figure 1: (R)-MeO-MOP and our ligands.
Scheme 1: Asymmetric Suzuki–Miyaura coupling. Reaction conditions: 1 equiv N-aryl-bromoaryl compounds, 2 equi...
Scheme 2: Asymmetric Suzuki–Miyaura coupling. Reaction conditions: 1 equiv of bromoaryl compounds, 2 equiv of...
Scheme 3: Gram-scale reaction.
Scheme 4: Based on our analysis and speculation, a possible intermediate structure is proposed [65,66].
Scheme 5: Method A for the synthesis of amide substrates.
Scheme 6: Method B for the synthesis of amide substrates.
Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules
- Valerian Dragutan,
- Ileana Dragutan,
- Albert Demonceau and
- Lionel Delaude
Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68
- of the dienic compound through a Suzuki–Miyaura coupling and Julia–Kocienski olefination, followed by a Yamaguchi lactonization, and an asymmetric epoxidation in the presence of (+)-diethyl tartrate, conveniently produced (−)-amphidinolide K (4, Scheme 7). In a remarkable work, Trost et al. [72
Graphical Abstract
Scheme 1: Intramolecular (A) and intermolecular (B) enyne metathesis reactions.
Scheme 2: Ene–yne and yne–ene mechanisms for intramolecular enyne metathesis reactions.
Scheme 3: Metallacarbene mechanism in intermolecular enyne metathesis.
Scheme 4: The Oguri strategy for accessing artemisinin analogs 1a–c through enyne metathesis.
Scheme 5: Access to the tetracyclic core of nanolobatolide (2) via tandem enyne metathesis followed by an Eu(...
Scheme 6: Synthesis of (−)-amphidinolide E (3) using an intermolecular enyne metathesis as the key step.
Scheme 7: Synthesis of amphidinolide K (4) by an enyne metathesis route.
Scheme 8: Trost synthesis of des-epoxy-amphidinolide N (5) [72].
Scheme 9: Enyne metathesis between the propargylic derivative and the allylic alcohol in the synthesis of the...
Scheme 10: Synthetic route to amphidinolide N (6a).
Scheme 11: Synthesis of the stereoisomeric precursors of amphidinolide V (7a and 7b) through alkyne ring-closi...
Scheme 12: Synthesis of the anthramycin precursor 8 from ʟ-methionine by a tandem enyne metathesis–cross metat...
Scheme 13: Synthesis of (−)‐clavukerin A (9) and (−)‐isoclavukerin A (10) by an enyne metathesis route startin...
Scheme 14: Synthesis of (−)-isoguaiene (11) through an enyne metathesis as the key step.
Scheme 15: Synthesis of erogorgiaene (12) by a tandem enyne metathesis/cross metathesis sequence using the sec...
Scheme 16: Synthesis of (−)-galanthamine (13) from isovanilin by an enyne metathesis.
Scheme 17: Application of enyne metathesis for the synthesis of kempene diterpenes 14a–c.
Scheme 18: Synthesis of the alkaloid (+)-lycoflexine (15) through enyne metathesis.
Scheme 19: Synthesis of the AB subunits of manzamine A (16a) and E (16b) by enyne metathesis.
Scheme 20: Jung's synthesis of rhodexin A (17) by enyne metathesis/cross metathesis reactions.
Scheme 21: Total synthesis of (−)-flueggine A (18) and (+)-virosaine B (19) from Weinreb amide by enyne metath...
Scheme 22: Access to virgidivarine (20) and virgiboidine (21) by an enyne metathesis route.
Scheme 23: Enyne metathesis approach to (−)-zenkequinone B (22).
Scheme 24: Access to C-aryl glycoside 23 by an intermolecular enyne metathesis/Diels–Alder cycloaddition.
Scheme 25: Synthesis of spiro-C-aryl glycoside 24 by a tandem intramolecular enyne metathesis/Diels–Alder reac...
Scheme 26: Pathways to (−)-exiguolide (25) by Trost’s Ru-catalyzed enyne cross-coupling and cross-metathesis [94].
Recent advances in Cu-catalyzed C(sp3)–Si and C(sp3)–B bond formation
- Balaram S. Takale,
- Ruchita R. Thakore,
- Elham Etemadi-Davan and
- Bruce H. Lipshutz
Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67
Graphical Abstract
Scheme 1: Pharmaceuticals possessing a silicon or boron atom.
Scheme 2: The first Cu-catalyzed C(sp3)–Si bond formation.
Scheme 3: Conversion of benzylic phosphate 6 to the corresponding silane.
Scheme 4: Conversion of alkyl triflates to alkylsilanes.
Scheme 5: Conversion of secondary alkyl triflates to alkylsilanes.
Scheme 6: Conversion of alkyl iodides to alkylsilanes.
Scheme 7: Trapping of intermediate radical through cascade reaction.
Scheme 8: Radical pathway for conversion of alkyl iodides to alkylsilanes.
Scheme 9: Conversion of alkyl ester of N-hydroxyphthalimide to alkylsilanes.
Scheme 10: Conversion of gem-dibromides to bis-silylalkanes.
Scheme 11: Conversion of imines to α-silylated amines (A) and the reaction pathway (B).
Scheme 12: Conversion of N-tosylimines to α-silylated amines.
Scheme 13: Screening of diamine ligands.
Scheme 14: Conversion of N-tert-butylsulfonylimines to α-silylated amines.
Scheme 15: Conversion of aldimines to nonracemic α-silylated amines.
Scheme 16: Conversion of N-tosylimines to α-silylated amines.
Scheme 17: Reaction pathway [A] and conversion of aldehydes to α-silylated alcohols [B].
Scheme 18: Conversion of aldehydes to benzhydryl silyl ethers.
Scheme 19: Conversion of ketones to 1,2-diols (A) and conversion of imines to 1,2-amino alcohols (B).
Scheme 20: Ligand screening (A) and conversion of aldehydes to α-silylated alcohols (B).
Scheme 21: Conversion of aldehydes to α-silylated alcohols.
Scheme 22: 1,4-Additions to α,β-unsaturated ketones.
Scheme 23: 1,4-Additions to unsaturated ketones to give β-silylated derivatives.
Scheme 24: Additions onto α,β-unsaturated lactones to give β-silylated lactones.
Scheme 25: Conversion of α,β-unsaturated to β-silylated lactams.
Scheme 26: Conversion of N-arylacrylamides to silylated oxindoles.
Scheme 27: Conversion of α,β-unsaturated carbonyl compounds to silylated tert-butylperoxides.
Scheme 28: Catalytic cycle for Cu(I) catalyzed α,β-unsaturated compounds.
Scheme 29: Conversion of p-quinone methides to benzylic silanes.
Scheme 30: Conversion of α,β-unsaturated ketimines to regio- and stereocontrolled allylic silanes.
Scheme 31: Conversion of α,β-unsaturated ketimines to enantioenriched allylic silanes.
Scheme 32: Regioselective conversion of dienedioates to allylic silanes.
Scheme 33: Conversion of alkenyl-substituted azaarenes to β-silylated adducts.
Scheme 34: Conversion of conjugated benzoxazoles to enantioenriched β-silylated adducts.
Scheme 35: Conversion of α,β-unsaturated carbonyl indoles to α-silylated N-alkylated indoles.
Scheme 36: Conversion of β-amidoacrylates to α-aminosilanes.
Scheme 37: Conversion of α,β-unsaturated ketones to enantioenriched β-silylated ketones, nitriles, and nitro d...
Scheme 38: Regio-divergent silacarboxylation of allenes.
Scheme 39: Silylation of diazocarbonyl compounds, (A) asymmetric and (B) racemic.
Scheme 40: Enantioselective hydrosilylation of alkenes.
Scheme 41: Conversion of 3-acylindoles to indolino-silanes.
Scheme 42: Proposed mechanism for the silylation of 3-acylindoles.
Scheme 43: Silyation of N-chlorosulfonamides.
Scheme 44: Conversion of acyl silanes to α-silyl alcohols.
Scheme 45: Conversion of N-tosylaziridines to β-silylated N-tosylamines.
Scheme 46: Conversion of N-tosylaziridines to silylated N-tosylamines.
Scheme 47: Conversion of 3,3-disubstituted cyclopropenes to silylated cyclopropanes.
Scheme 48: Conversion of conjugated enynes to 1,3-bis(silyl)propenes.
Scheme 49: Proposed sequence for the Cu-catalyzed borylation of substituted alkenes.
Scheme 50: Cu-catalyzed synthesis of nonracemic allylic boronates.
Scheme 51: Cu–NHC catalyzed synthesis of α-substituted allylboronates.
Scheme 52: Synthesis of α-chiral (γ-alkoxyallyl)boronates.
Scheme 53: Cu-mediated formation of nonracemic cis- or trans- 2-substituted cyclopropylboronates.
Scheme 54: Cu-catalyzed synthesis of γ,γ-gem-difluoroallylboronates.
Scheme 55: Cu-catalyzed hydrofunctionalization of internal alkenes and vinylarenes.
Scheme 56: Cu-catalyzed Markovnikov and anti-Markovnikov borylation of alkenes.
Scheme 57: Cu-catalyzed borylation/ortho-cyanation/Cope rearrangement.
Scheme 58: Borylfluoromethylation of alkenes.
Scheme 59: Cu-catalyzed synthesis of tertiary nonracemic alcohols.
Scheme 60: Synthesis of densely functionalized and synthetically versatile 1,2- or 4,3-borocyanated 1,3-butadi...
Scheme 61: Cu-catalyzed trifunctionalization of allenes.
Scheme 62: Cu-catalyzed selective arylborylation of arenes.
Scheme 63: Asymmetric borylative coupling between styrenes and imines.
Scheme 64: Regio-divergent aminoboration of unactivated terminal alkenes.
Scheme 65: Cu-catalyzed 1,4-borylation of α,β-unsaturated ketones.
Scheme 66: Cu-catalyzed protodeboronation of α,β-unsaturated ketones.
Scheme 67: Cu-catalyzed β-borylation of α,β-unsaturated imines.
Scheme 68: Cu-catalyzed synthesis of β-trifluoroborato carbonyl compounds.
Scheme 69: Asymmetric 1,4-borylation of α,β-unsaturated carbonyl compounds.
Scheme 70: Cu-catalyzed ACB and ACA reactions of α,β-unsaturated 2-acyl-N-methylimidazoles.
Scheme 71: Cu-catalyzed diborylation of aldehydes.
Scheme 72: Umpolung pathway for chiral, nonracemic tertiary alcohol synthesis (top) and proposed mechanism for...
Scheme 73: Cu-catalyzed synthesis of α-hydroxyboronates.
Scheme 74: Cu-catalyzed borylation of ketones.
Scheme 75: Cu-catalyzed borylation of unactivated alkyl halides.
Scheme 76: Cu-catalyzed borylation of allylic difluorides.
Scheme 77: Cu-catalyzed borylation of cyclic and acyclic alkyl halides.
Scheme 78: Cu-catalyzed borylation of unactivated alkyl chlorides and bromides.
Scheme 79: Cu-catalyzed decarboxylative borylation of carboxylic acids.
Scheme 80: Cu-catalyzed borylation of benzylic, allylic, and propargylic alcohols.
Synthesis of triphenylene-fused phosphole oxides via C–H functionalizations
- Md. Shafiqur Rahman and
- Naohiko Yoshikai
Beilstein J. Org. Chem. 2020, 16, 524–529, doi:10.3762/bjoc.16.48
- π-extension through a Suzuki–Miyaura coupling, Sonogashira coupling, and electrophilic alkyne carbocyclization [18]. Given the successful synthesis of the angularly fused phosphahelicenes, we became interested in the further exploitation of 7-hydroxybenzo[b]phosphole as an intermediate for the
Graphical Abstract
Figure 1: Examples of functional molecules based on π-extended phospholes.
Scheme 1: Syntheses of PAH-fused phospholes featuring a 7-hydroxybenzo[b]phosphole as a key intermediate.
Scheme 2: Synthesis of phosphole-fused ortho-teraryl compounds 7.
Scheme 3: Oxidative cyclization of phosphole-fused ortho-teraryl compounds 7 into triphenylene-fused phosphol...
Figure 2: ORTEP drawings of compound 8a (thermal ellipsoids set at 50% probability). a) top view; b) side vie...
Figure 3: UV–vis absorption (solid lines) and fluorescence (dashed lines) spectra of compounds 8a–c.
Palladium-catalyzed synthesis and nucleotide pyrophosphatase inhibition of benzo[4,5]furo[3,2-b]indoles
- Hoang Huy Do,
- Saif Ullah,
- Alexander Villinger,
- Joanna Lecka,
- Jean Sévigny,
- Peter Ehlers,
- Jamshed Iqbal and
- Peter Langer
Beilstein J. Org. Chem. 2019, 15, 2830–2839, doi:10.3762/bjoc.15.276
- selected inhibitors on isozymes ENPP1 and ENPP3 modelled proteins were in accordance with in vitro experimental studies. Conclusion In conclusion, we have reported a convenient strategy for the preparation of benzo[4,5]furo[3,2-b]indoles based on Suzuki–Miyaura coupling reactions followed by Pd-catalyzed
Graphical Abstract
Figure 1: Pharmacologically relevant furoindoles.
Scheme 1: Synthesis of benzo[4,5]furo[3,2-b]indoles 5a–j. Conditions: (i) 1.2 equiv 2-bromophenylboronic acid...
Figure 2: Ortep of 5c (propability of ellipsoids: 45%).
Figure 3: Diindolofurans 6a–e.
Figure 4: Illustration of binding poses of selected inhibitors for the ENPP1 homology model: (a): suramin, (b...
Figure 5: 3D poses of docked selected inhibitors inside homology model of ENPP3. (a): suramin, (b): 5e, (c): ...
Acid-catalyzed rearrangements in arenes: interconversions in the quaterphenyl series
- Sarah L. Skraba-Joiner,
- Carter J. Holt and
- Richard P. Johnson
Beilstein J. Org. Chem. 2019, 15, 2655–2663, doi:10.3762/bjoc.15.258
- , samples of m,p’- (13), o,p’- (15), o,m’- (16), and o,o’-quaterphenyl (17) were synthesized as shown in Scheme 3. Suzuki–Miyaura coupling was used to synthesize 13, 15, and 16 from the corresponding aryl bromides and boronic acids [35]. o,o’-Quaterphenyl (17) was synthesized by homo-coupling of 2
- through time-of-flight matrix assisted laser desorption ionization (MALDI–TOF–MS) mass spectrometry, using sulfur as a matrix. Suzuki–Miyaura coupling to form m,p’-quaterphenyl (13) [35]: 4-Biphenylboronic acid (0.18 g, 0.91 mmol) and 1 M K2CO3 (1.5 mL) were added to a 10 mL Pyrex microwave tube. 3
- (400 MHz, CDCl3) δ 7.87–7.85 (m, 1H), 7.76–7.69 (m, 4H), 7.69–7.64 (m, 4H), 7.64–7.58 (m, 2H), 7.57–7.52 (m, 1H), 7.50–7.45 (m, 4H), 7.41–7.35 (m, 2H). Suzuki–Miyaura coupling to form o,p’-quaterphenyl (15) [35]: K2CO3 (0.91 g, 6.6 mmol) and water (7.7 mL) were combined in a 25 mL round bottom flask
Graphical Abstract
Scheme 1: Acid-catalyzed rearrangements of arenes.
Scheme 2: Rearrangement of quaterphenyl isomers by phenyl shifts.
Scheme 3: Synthesis of quaterphenyl isomers.
Scheme 4: Rearrangement of quaterphenyl isomers via (a) 1,2-phenyl shift and (b) 1,2-biphenyl shift.
Figure 1: Pathways for terminal 1,2-phenyl shifts in quaterphenyl isomers calculated with IEFPCM(DCE)/B3LYP/6...
Figure 2: Pathways for 1,2-biphenyl shifts in quaterphenyl isomers calculated with IEFPCM(DCE)/B3LYP/6-31+G(d...
A new approach to silicon rhodamines by Suzuki–Miyaura coupling – scope and limitations
- Thines Kanagasundaram,
- Antje Timmermann,
- Carsten S. Kramer and
- Klaus Kopka
Beilstein J. Org. Chem. 2019, 15, 2569–2576, doi:10.3762/bjoc.15.250
- functionalized with free acid moieties are directly accessible in contrast to previously described methods. Keywords: cross coupling; fluorescent dyes; near-infrared (NIR) dyes; silicon rhodamines; Suzuki–Miyaura coupling; Introduction Silicon rhodamines are versatile fluorescent dyes that found extensive use
- , we wanted to investigate if these dyes are also accessible by Suzuki–Miyaura coupling. Results and Discussion Optimization of reaction conditions At first we investigated the effects of different catalysts and boron compounds on the synthesis of silicon rhodamine 22 via Suzuki–Miyaura cross coupling
- explored the substrate scope of the Suzuki–Miyaura coupling by screening commercially available boronic acids (Scheme 4, Table 2). Hereby, PdCl2(dppf) was also tested in order to suppress the formation of the inseparable phosphonium cation species. At first, we investigated the use of 3-boronobenzoic acid
Graphical Abstract
Scheme 1: Different synthetic approaches to silicon rhodamine dyes.
Scheme 2: Previous work from Calitree [29] and Urano [22,28] on the Suzuki–Miyaura coupling of triflates, derived from x...
Scheme 3: Optimization of cross-coupling conditions of triflate 21, derived from Si-xanthone 12, with boron s...
Scheme 4: Coupling reactions of silicon xanthone 12 with different boron species (23b–30b, 31).
Mono- and bithiophene-substituted diarylethene photoswitches with emissive open or closed forms
- A. Lennart Schleper,
- Mariano L. Bossi,
- Vladimir N. Belov and
- Stefan W. Hell
Beilstein J. Org. Chem. 2019, 15, 2344–2354, doi:10.3762/bjoc.15.227
- regioisomeric bromides were also formed, but they were separated by column chromatography on the next step. Bithiophene 11 was prepared in 74% yield by using a Suzuki–Miyaura coupling (catalyzed by PEPPSI-IPr) between boronic ester 9 and bromide 10 [13][14]. Boronation of bithiophene 11 was achieved under
- , AsOTh2, and SyOTh2 (Figure 1) were obtained using a standard procedure for a Suzuki–Miyaura coupling of iodides 4, 5, 7, and 8 with boronic acid esters 9 and 12 (see Scheme 3). Throughout the text, abbreviations “As” and “Sy” denote asymmetric and symmetric substitution patterns, respectively; “O
- esters 9 and 12 (bpy – 4,4’-di-tert-butyl-2,2’-dipyridine; COD – cycloocta-1,5-diene; NBS – N-bromosuccinimide, DCM – dichloromethane). Photoswitchable diarylethenes AsTh1, SyTh1, AsTh2, SyTh2, AsOTh1, SyOTh1, AsOTh2, and SyOTh2 synthesized via a Suzuki–Miyaura coupling. Conditions: 60 °C, argon
Graphical Abstract
Figure 1: Structures of “thiophenylated” DAEs prepared and studied in this work.
Scheme 1: Synthesis routes towards mono- and diiodinated core structures 4, 5, 7, and 8.
Scheme 2: Synthesis of thiophene- and bithiopheneboronic esters 9 and 12 (bpy – 4,4’-di-tert-butyl-2,2’-dipyr...
Scheme 3: Photoswitchable diarylethenes AsTh1, SyTh1, AsTh2, SyTh2, AsOTh1, SyOTh1, AsOTh2, and SyOTh2 synthe...
Scheme 4: Saponification of methyl ester groups in tetraester SyTh2 leading to tetracarboxylic acid SyTh2-H.
Figure 2: Absorption (A) and emission (B) spectra of SyTh2 in acetonitrile in the course of the cyclization r...
Figure 3: Absorption spectra of the OFs (A) and CFs (B) of AsTh1 (a), SyTh1 (b), AsTh2 (c), SyTh2 (d), AsOTh1...
Figure 4: Solutions of compounds AsTh1 (a), SyTh1 (b), AsTh2 (c), SyTh2 (d), AsOTh1 (e), SyOTh1 (f), AsOTh2 (...
Figure 5: Fatigue resistances of compounds SyOTh1 (A and B) and SyTh1 (C). Parts A and C show the absorbance ...
Figure 6: (A) Absorption spectra of compound SyOTh1 in MeCN at the photostationary states under irradiation w...
Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage
- Gagandeep Kour Reen,
- Ashok Kumar and
- Pratibha Sharma
Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165
- -catalyzed cross-coupling reactions have laid down the foundation of new C–C bond formations [50][51]. A number of Pd-catalyzed organic reactions viz., C–N coupling, amination and intramolecular amidation, cyclization, and Suzuki–Miyaura coupling [52][53][54][55] have recently been reported in the literature
Graphical Abstract
Figure 1: Various drugs having IP nucleus.
Figure 2: Participation percentage of various TMs for the syntheses of IPs.
Scheme 1: CuI–NaHSO4·SiO2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 2: Experimental examination of reaction conditions.
Scheme 3: One-pot tandem reaction for the synthesis of 2-haloimidazopyridines.
Scheme 4: Mechanistic scheme for the synthesis of 2-haloimidazopyridine.
Scheme 5: Copper-MOF-catalyzed three-component reaction (3-CR) for imidazo[1,2-a]pyridines.
Scheme 6: Mechanism for copper-MOF-driven synthesis.
Scheme 7: Heterogeneous synthesis via titania-supported CuCl2.
Scheme 8: Mechanism involving oxidative C–H functionalization.
Scheme 9: Heterogeneous synthesis of IPs.
Scheme 10: One-pot regiospecific synthesis of imidazo[1,2-a]pyridines.
Scheme 11: Vinyl azide as an unprecedented substrate for imidazo[1,2-a]pyridines.
Scheme 12: Radical pathway.
Scheme 13: Cu(I)-catalyzed transannulation approach for imidazo[1,5-a]pyridines.
Scheme 14: Plausible radical pathway for the synthesis of imidazo[1,5-a]pyridines.
Scheme 15: A solvent-free domino reaction for imidazo[1,2-a]pyridines.
Scheme 16: Cu-NPs-mediated synthesis of imidazo[1,2-a]pyridines.
Scheme 17: CuI-catalyzed synthesis of isoxazolylimidazo[1,2-a]pyridines.
Scheme 18: Functionalization of 4-bromo derivative via Sonogashira coupling reaction.
Scheme 19: A plausible reaction pathway.
Scheme 20: Cu(I)-catalyzed intramolecular oxidative C–H amidation reaction.
Scheme 21: One-pot synthetic reaction for imidazo[1,2-a]pyridine.
Scheme 22: Plausible reaction mechanism.
Scheme 23: Cu(OAc)2-promoted synthesis of imidazo[1,2-a]pyridines.
Scheme 24: Mechanism for aminomethylation/cycloisomerization of propiolates with imines.
Scheme 25: Three-component synthesis of imidazo[1,2-a]pyridines.
Figure 3: Scope of pyridin-2(1H)-ones and acetophenones.
Scheme 26: CuO NPS-promoted A3 coupling reaction.
Scheme 27: Cu(II)-catalyzed C–N bond formation reaction.
Scheme 28: Mechanism involving Chan–Lam/Ullmann coupling.
Scheme 29: Synthesis of formyl-substituted imidazo[1,2-a]pyridines.
Scheme 30: A tandem sp3 C–H amination reaction.
Scheme 31: Probable mechanistic approach.
Scheme 32: Dual catalytic system for imidazo[1,2-a]pyridines.
Scheme 33: Tentative mechanism.
Scheme 34: CuO/CuAl2O4/ᴅ-glucose-promoted 3-CCR.
Scheme 35: A tandem CuOx/OMS-2-based synthetic strategy.
Figure 4: Biomimetic catalytic oxidation in the presence of electron-transfer mediators (ETMs).
Scheme 36: Control experiment.
Scheme 37: Copper-catalyzed C(sp3)–H aminatin reaction.
Scheme 38: Reaction of secondary amines.
Scheme 39: Probable mechanistic pathway.
Scheme 40: Coupling reaction of α-azidoketones.
Scheme 41: Probable pathway.
Scheme 42: Probable mechanism with free energy calculations.
Scheme 43: MCR for cyanated IP synthesis.
Scheme 44: Substrate scope for the reaction.
Scheme 45: Reaction mechanism.
Scheme 46: Probable mechanistic pathway for Cu/ZnAl2O4-catalyzed reaction.
Scheme 47: Copper-catalyzed double oxidative C–H amination reaction.
Scheme 48: Application towards different coupling reactions.
Scheme 49: Reaction mechanism.
Scheme 50: Condensation–cyclization approach for the synthesis of 1,3-diarylated imidazo[1,5-a]pyridines.
Scheme 51: Optimized reaction conditions.
Scheme 52: One-pot 2-CR.
Scheme 53: One-pot 3-CR without the isolation of chalcone.
Scheme 54: Copper–Pybox-catalyzed cyclization reaction.
Scheme 55: Mechanistic pathway catalyzed by Cu–Pybox complex.
Scheme 56: Cu(II)-promoted C(sp3)-H amination reaction.
Scheme 57: Wider substrate applicability for the reaction.
Scheme 58: Plausible reaction mechanism.
Scheme 59: CuI assisted C–N cross-coupling reaction.
Scheme 60: Probable reaction mechanism involving sp3 C–H amination.
Scheme 61: One-pot MCR-catalyzed by CoFe2O4/CNT-Cu.
Scheme 62: Mechanistic pathway.
Scheme 63: Synthetic scheme for 3-nitroimidazo[1,2-a]pyridines.
Scheme 64: Plausible mechanism for CuBr-catalyzed reaction.
Scheme 65: Regioselective synthesis of halo-substituted imidazo[1,2-a]pyridines.
Scheme 66: Synthesis of 2-phenylimidazo[1,2-a]pyridines.
Scheme 67: Synthesis of diarylated compounds.
Scheme 68: CuBr2-mediated one-pot two-component oxidative coupling reaction.
Scheme 69: Decarboxylative cyclization route to synthesize 1,3-diarylimidazo[1,5-a]pyridines.
Scheme 70: Mechanistic pathway.
Scheme 71: C–H functionalization reaction of enamines to produce diversified heterocycles.
Scheme 72: A plausible mechanism.
Scheme 73: CuI-promoted aerobic oxidative cyclization reaction of ketoxime acetates and pyridines.
Scheme 74: CuI-catalyzed pathway for the formation of imidazo[1,2-a]pyridine.
Scheme 75: Mechanistic pathway.
Scheme 76: Mechanistic rationale for the synthesis of products.
Scheme 77: Copper-catalyzed synthesis of vinyloxy-IP.
Scheme 78: Regioselective product formation with propiolates.
Scheme 79: Proposed mechanism for vinyloxy-IP formation.
Scheme 80: Regioselective synthesis of 3-hetero-substituted imidazo[1,2-a]pyridines with different reaction su...
Scheme 81: Mechanistic pathway.
Scheme 82: CuI-mediated synthesis of 3-formylimidazo[1,2-a]pyridines.
Scheme 83: Radical pathway for 3-formylated IP synthesis.
Scheme 84: Pd-catalyzed urea-cyclization reaction for IPs.
Scheme 85: Pd-catalyzed one-pot-tandem amination and intramolecular amidation reaction.
Figure 5: Scope of aniline nucleophiles.
Scheme 86: Pd–Cu-catalyzed Sonogashira coupling reaction.
Scheme 87: One-pot amide coupling reaction for the synthesis of imidazo[4,5-b]pyridines.
Scheme 88: Urea cyclization reaction for the synthesis of two series of pyridines.
Scheme 89: Amidation reaction for the synthesis of imidazo[4,5-b]pyridines.
Figure 6: Amide scope.
Scheme 90: Pd NPs-catalyzed 3-component reaction for the synthesis of 2,3-diarylated IPs.
Scheme 91: Plausible mechanistic pathway for Pd NPs-catalyzed MCR.
Scheme 92: Synthesis of chromenoannulated imidazo[1,2-a]pyridines.
Scheme 93: Mechanism for the synthesis of chromeno-annulated IPs.
Scheme 94: Zinc oxide NRs-catalyzed synthesis of imidazo[1,2-a]azines/diazines.
Scheme 95: Zinc oxide-catalyzed isocyanide based GBB reaction.
Scheme 96: Reaction pathway for ZnO-catalyzed GBB reaction.
Scheme 97: Mechanistic pathway.
Scheme 98: ZnO NRs-catalyzed MCR for the synthesis of imidazo[1,2-a]azines.
Scheme 99: Ugi type GBB three-component reaction.
Scheme 100: Magnetic NPs-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 101: Regioselective synthesis of 2-alkoxyimidazo[1,2-a]pyridines catalyzed by Fe-SBA-15.
Scheme 102: Plausible mechanistic pathway for the synthesis of 2-alkoxyimidazopyridine.
Scheme 103: Iron-catalyzed synthetic approach.
Scheme 104: Iron-catalyzed aminooxygenation reaction.
Scheme 105: Mechanistic pathway.
Scheme 106: Rh(III)-catalyzed double C–H activation of 2-substituted imidazoles and alkynes.
Scheme 107: Plausible reaction mechanism.
Scheme 108: Rh(III)-catalyzed non-aromatic C(sp2)–H bond activation–functionalization for the synthesis of imid...
Scheme 109: Reactivity and selectivity of different substrates.
Scheme 110: Rh-catalyzed direct C–H alkynylation by Li et al.
Scheme 111: Suggested radical mechanism.
Scheme 112: Scandium(III)triflate-catalyzed one-pot reaction and its mechanism for the synthesis of benzimidazo...
Scheme 113: RuCl3-assisted Ugi-type Groebke–Blackburn condensation reaction.
Scheme 114: C-3 aroylation via Ru-catalyzed two-component reaction.
Scheme 115: Regioselective synthetic mechanism.
Scheme 116: La(III)-catalyzed one-pot GBB reaction.
Scheme 117: Mechanistic approach for the synthesis of imidazo[1,2-a]pyridines.
Scheme 118: Synthesis of imidazo[1,2-a]pyridine using LaMnO3 NPs under neat conditions.
Scheme 119: Mechanistic approach.
Scheme 120: One-pot 3-CR for regioselective synthesis of 2-alkoxy-3-arylimidazo[1,2-a]pyridines.
Scheme 121: Formation of two possible products under optimization of the catalysts.
Scheme 122: Mechanistic strategy for NiFe2O4-catalyzed reaction.
Scheme 123: Two-component reaction for synthesizing imidazodipyridiniums.
Scheme 124: Mechanistic scheme for the synthesis of imidazodipyridiniums.
Scheme 125: CuI-catalyzed arylation of imidazo[1,2-a]pyridines.
Scheme 126: Mechanism for arylation reaction.
Scheme 127: Cupric acetate-catalyzed double carbonylation approach.
Scheme 128: Radical mechanism for double carbonylation of IP.
Scheme 129: C–S bond formation reaction catalyzed by cupric acetate.
Scheme 130: Cupric acetate-catalyzed C-3 formylation approach.
Scheme 131: Control experiments for signifying the role of DMSO and oxygen.
Scheme 132: Mechanism pathway.
Scheme 133: Copper bromide-catalyzed CDC reaction.
Scheme 134: Extension of the substrate scope.
Scheme 135: Plausible radical pathway.
Scheme 136: Transannulation reaction for the synthesis of imidazo[1,5-a]pyridines.
Scheme 137: Plausible reaction pathway for denitrogenative transannulation.
Scheme 138: Cupric acetate-catalyzed C-3 carbonylation reaction.
Scheme 139: Plausible mechanism for regioselective C-3 carbonylation.
Scheme 140: Alkynylation reaction at C-2 of 3H-imidazo[4,5-b]pyridines.
Scheme 141: Two-way mechanism for C-2 alkynylation of 3H-imidazo[4,5-b]pyridines.
Scheme 142: Palladium-catalyzed SCCR approach.
Scheme 143: Palladium-catalyzed Suzuki coupling reaction.
Scheme 144: Reaction mechanism.
Scheme 145: A phosphine free palladium-catalyzed synthesis of C-3 arylated imidazopyridines.
Scheme 146: Palladium-mediated Buchwald–Hartwig cross-coupling reaction.
Figure 7: Structure of the ligands optimized.
Scheme 147: Palladium acetate-catalyzed direct arylation of imidazo[1,2-a]pyridines.
Scheme 148: Palladium acetate-catalyzed mechanistic pathway.
Scheme 149: Palladium acetate-catalyzed regioselective arylation reported by Liu and Zhan.
Scheme 150: Mechanism for selective C-3 arylation of IP.
Scheme 151: Pd(II)-catalyzed alkenylation reaction with styrenes.
Scheme 152: Pd(II)-catalyzed alkenylation reaction with acrylates.
Scheme 153: A two way mechanism.
Scheme 154: Double C–H activation reaction catalyzed by Pd(OAc)2.
Scheme 155: Probable mechanism.
Scheme 156: Palladium-catalyzed decarboxylative coupling.
Scheme 157: Mechanistic cycle for decarboxylative arylation reaction.
Scheme 158: Ligand-free approach for arylation of imidazo[1,2-a]pyridine-3-carboxylic acids.
Scheme 159: Mechanism for ligandless arylation reaction.
Scheme 160: NHC-Pd(II) complex assisted arylation reaction.
Scheme 161: C-3 arylation of imidazo[1,2-a]pyridines with aryl bromides catalyzed by Pd(OAc)2.
Scheme 162: Pd(II)-catalyzed C-3 arylations with aryl tosylates and mesylates.
Scheme 163: CDC reaction for the synthesis of imidazo[1,2-a]pyridines.
Scheme 164: Plausible reaction mechanism for Pd(OAc)2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 165: Pd-catalyzed C–H amination reaction.
Scheme 166: Mechanism for C–H amination reaction.
Scheme 167: One-pot synthesis for 3,6-di- or 2,3,6-tri(hetero)arylimidazo[1,2-a]pyridines.
Scheme 168: C–H/C–H cross-coupling reaction of IPs and azoles catalyzed by Pd(II).
Scheme 169: Mechanistic cycle.
Scheme 170: Rh-catalyzed C–H arylation reaction.
Scheme 171: Mechanistic pathway for C–H arylation of imidazo[1,2-a]pyridine.
Scheme 172: Rh(III)-catalyzed double C–H activation of 2-phenylimidazo[1,2-a]pyridines and alkynes.
Scheme 173: Rh(III)-catalyzed mechanistic pathway.
Scheme 174: Rh(III)-mediated oxidative coupling reaction.
Scheme 175: Reactions showing functionalization of the product obtained by the group of Kotla.
Scheme 176: Mechanism for Rh(III)-catalyzed oxidative coupling reaction.
Scheme 177: Rh(III)-catalyzed C–H activation reaction.
Scheme 178: Mechanistic cycle.
Scheme 179: Annulation reactions of 2-arylimidazo[1,2-a]pyridines and alkynes.
Scheme 180: Two-way reaction mechanism for annulations reaction.
Scheme 181: [RuCl2(p-cymene)]2-catalyzed C–C bond formation reaction.
Scheme 182: Reported reaction mechanism.
Scheme 183: Fe(III) catalyzed C-3 formylation approach.
Scheme 184: SET mechanism-catalyzed by Fe(III).
Scheme 185: Ni(dpp)Cl2-catalyzed KTC coupling.
Scheme 186: Pd-catalyzed SM coupling.
Scheme 187: Vanadium-catalyzed coupling of IP and NMO.
Scheme 188: Mechanistic cycle.
Scheme 189: Selective C3/C5–H bond functionalizations by mono and bimetallic systems.
Scheme 190: rGO-Ni@Pd-catalyzed C–H bond arylation of imidazo[1,2-a]pyridine.
Scheme 191: Mechanistic pathway for heterogeneously catalyzed arylation reaction.
Scheme 192: Zinc triflate-catalyzed coupling reaction of substituted propargyl alcohols.
Synthesis of pyrrolo[1,2-a]quinolines by formal 1,3-dipolar cycloaddition reactions of quinolinium salts
- Anthony Choi,
- Rebecca M. Morley and
- Iain Coldham
Beilstein J. Org. Chem. 2019, 15, 1480–1484, doi:10.3762/bjoc.15.149
- could be converted to other derivatives by Suzuki–Miyaura coupling, reduction or oxidation reactions. Keywords: azomethine ylide; cycloaddition; heterocycle; pyrrolidine; stereoselective; Introduction Cycloaddition reactions of azomethine ylides are an important class of pericyclic reactions that give
- ). The adducts could be reduced, oxidised, or could undergo Suzuki–Miyaura coupling to give different substituted dihydro- and tetrahydroquinoline derivatives. Single crystal X-ray structure for 7c. Single crystal X-ray structure for 9. Reaction of ketone 1 with electron-deficient alkenes 2. Reactions of
- ester 4 and amide 5 with electron-deficient alkenes 6. Reactions of ester 4 and amide 5 with N-methylmaleimide. Reduction and oxidation of adducts 9 and 10. Formation of amides 15a and 15b and Suzuki–Miyaura coupling to yield 16. Supporting Information Supporting Information File 322: Experimental
Graphical Abstract
Scheme 1: Reaction of ketone 1 with electron-deficient alkenes 2.
Scheme 2: Reactions of ester 4 and amide 5 with electron-deficient alkenes 6.
Figure 1: Single crystal X-ray structure for 7c.
Scheme 3: Reactions of ester 4 and amide 5 with N-methylmaleimide.
Figure 2: Single crystal X-ray structure for 9.
Scheme 4: Reduction and oxidation of adducts 9 and 10.
Scheme 5: Formation of amides 15a and 15b and Suzuki–Miyaura coupling to yield 16.
Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams
- Edorta Martínez de Marigorta,
- Jesús M. de Los Santos,
- Ana M. Ochoa de Retana,
- Javier Vicario and
- Francisco Palacios
Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104
- , presumably by changing the anionic character of the palladium complex to cationic in intermediate 135. Finally, the Suzuki–Miyaura coupling of palladium salt 135 with boronic acid derivative 130 would provide the final oxindoles 131 or 132. Finally, is worth mentioning an example of a multicomponent
Graphical Abstract
Figure 1: γ-Lactam-derived structures considered in this review.
Figure 2: Alkaloids containing an isoindolinone moiety.
Figure 3: Alkaloids containing the 2-oxindole ring system.
Figure 4: Drugs and biological active compounds containing an isoindolinone moiety.
Figure 5: Drugs and biologically active compounds bearing a 2-oxindole skeleton.
Scheme 1: Three-component reaction of benzoic acid 1, amides 2 and DMSO (3).
Scheme 2: Copper-catalysed three-component reaction of 2-iodobenzoic acids 10, alkynylcarboxylic acids 11 and...
Scheme 3: Proposed mechanism for the formation of methylene isoindolinones 13.
Scheme 4: Copper-catalysed three-component reaction of 2-iodobenzamide 17, terminal alkyne 18 and pyrrole or ...
Scheme 5: Palladium-catalysed three-component reaction of ethynylbenzamides 21, secondary amines 22 and CO (23...
Scheme 6: Proposed mechanism for the formation of methyleneisoindolinones 24.
Scheme 7: Copper-catalysed three-component reaction of formyl benzoate 29, amines 2 and alkynes 18.
Scheme 8: Copper-catalysed three-component reaction of formylbenzoate 29, amines 2 and ketones 31.
Scheme 9: Non-catalysed (A) and phase-transfer catalysed (B) three-component reactions of formylbenzoic acids ...
Scheme 10: Proposed mechanism for the formation of isoindolinones 36.
Scheme 11: Three-component reaction of formylbenzoic acid 33, amines 2 and fluorinated silyl ethers 39.
Scheme 12: Three-component Ugi reaction of 2-formylbenzoic acid (33), diamines 41 and isocyanides 42.
Scheme 13: Non-catalysed (A, B) and chiral phosphoric acid promoted (C) three-component Ugi reactions of formy...
Scheme 14: Proposed mechanism for the enantioselective formation of isoindolinones 46.
Scheme 15: Three-component reaction of benzoic acids 33 or 54, amines 2 and TMSCN (52).
Scheme 16: Several variations of the three-component reaction of formylbenzoic acids 33, amines 2 and isatoic ...
Scheme 17: Proposed mechanism for the synthesis of isoindoloquinazolinones 57.
Scheme 18: Three-component reaction of isobenzofuranone 61, amines 2 and isatoic anhydrides 56.
Scheme 19: Palladium-catalysed three-component reaction of 2-aminobenzamides 59, 2-bromobenzaldehydes 62 and C...
Scheme 20: Proposed mechanism for the palladium-catalysed synthesis of isoindoloquinazolinones 57.
Scheme 21: Four-component reaction of 2-vinylbenzoic acids 67, aryldioazonium tetrafluoroborates 68, DABCO·(SO2...
Scheme 22: Plausible mechanism for the formation of isoindolinones 71.
Scheme 23: Three-component reaction of trimethylsilylaryltriflates 77, isocyanides 42 and CO2 (78).
Scheme 24: Plausible mechanism for the three-component synthesis of phthalimides 79.
Scheme 25: Copper-catalysed three-component reaction of 2-formylbenzonitriles 85, arenes 86 and diaryliodonium...
Scheme 26: Copper-catalysed three-component reaction of 2-formylbenzonitriles 85, diaryliodonium salts 87 and ...
Scheme 27: Proposed mechanism for the formation of 2,3-diarylisoindolinones 88, 89 and 92.
Scheme 28: Palladium-catalysed three-component reaction of chloroquinolinecarbaldehydes 97 with isocyanides 42...
Scheme 29: Palladium-catalysed three-component reaction of imines 99 with CO (23) and ortho-iodoarylimines 100....
Scheme 30: Palladium-catalysed three-component reaction of amines 2 with CO (23) and aryl iodide 105.
Scheme 31: Three-component reaction of 2-ethynylanilines 109, perfluoroalkyl iodides 110 and carbon monoxide (...
Scheme 32: Ultraviolet-induced three-component reaction of N-(2-iodoaryl)acrylamides 113, DABCO·(SO2)2 (69) an...
Scheme 33: Proposed mechanism for the preparation of oxindoles 115.
Scheme 34: Three-component reaction of acrylamide 113, CO (23) and 1,4-benzodiazepine 121.
Scheme 35: Multicomponent reaction of sulfonylacrylamides 123, aryldiazonium tetrafluoroborates 68 and DABCO·(...
Scheme 36: Proposed mechanism for the preparation of oxindoles 124.
Scheme 37: Three-component reaction of N-arylpropiolamides 128, aryl iodides 129 and boronic acids 130.
Scheme 38: Proposed mechanism for the formation of diarylmethylene- and diarylallylideneoxindoles 131 and 132.
Scheme 39: Three-component reaction of cyclohexa-1,3-dione (136), amines 2 and alkyl acetylenedicarboxylates 1...
Scheme 40: Proposed mechanism for the formation of 2-oxindoles 138.
Synthesis and biological activity of methylated derivatives of the Pseudomonas metabolites HHQ, HQNO and PQS
- Sven Thierbach,
- Max Wienhold,
- Susanne Fetzner and
- Ulrich Hennecke
Beilstein J. Org. Chem. 2019, 15, 187–193, doi:10.3762/bjoc.15.18
- , its isolation should be possible and enable further modification, for example by ipso-substitution with heteroatom electrophiles. The application of the boronic acid in Suzuki–Miyaura coupling should also be possible [30][31]. Growth inhibition experiments against S. aureus showed that HQNO
Graphical Abstract
Scheme 1: Methylation of HHQ (1).
Scheme 2: Synthesis of methylated HQNO derivatives.
Scheme 3: Synthesis of methylated PQS derivatives.
Figure 1: Overview of AQ compounds (A), and effect of AQs on the growth of S. aureus Newman (B). 24-Well plat...
Figure 2: Inhibition of cellular O2 consumption rate (cOCR) of S. aureus Newman. Cell suspensions (OD600 nm o...
Figure 3: Impact on AQ quorum sensing by the newly synthesized AQ derivatives. Cultures of P. aeruginosa PAO1...
Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate
- Eloi P. Coutant,
- Vincent Hervin,
- Glwadys Gagnot,
- Candice Ford,
- Racha Baatallah and
- Yves L. Janin
Beilstein J. Org. Chem. 2018, 14, 2853–2860, doi:10.3762/bjoc.14.264
- modifications of some of the intermediates – using Suzuki–Miyaura coupling or cycloadditions – before undertaking the oximation step – provided accesses to further α-amino esters. Moreover, other pathways to α-hydroxyimino esters were explored including an attempt to improve the cycloadditions between ethyl β
Graphical Abstract
Scheme 1: Malonate-based retrosynthesis of α-amino esters.
Scheme 2: Some side products and synthesis of α-amino ester 10.
Scheme 3: Syntheses of α-amino esters 22, 24, 26, 28 and 33.
Scheme 4: Syntheses of α-amino esters 38, 41 and 46a,b.
Scheme 5: Syntheses of α-amino esters 53 and 58.
Synthesis and biological evaluation of 1,2-disubstituted 4-quinolone analogues of Pseudonocardia sp. natural products
- Stephen M. Geddis,
- Teodora Coroama,
- Suzanne Forrest,
- James T. Hodgkinson,
- Martin Welch and
- David R. Spring
Beilstein J. Org. Chem. 2018, 14, 2680–2688, doi:10.3762/bjoc.14.245
- first developed a strategy which constructed natural products 1–4 by uniting the quinolone cores with the side chain by means of an sp2–sp3 Suzuki–Miyaura coupling reaction [8]. Whilst these compounds unfortunately provided no modulation of PQS quorum screening (as determined using a heterologous
Graphical Abstract
Figure 1: A family of quinolone natural products 1–8, which were first isolated from Pseudonocardia sp. CL384...
Scheme 1: Proposed use of the chemistry developed towards the total synthesis of 5 and 6 for generation of na...
Scheme 2: Sonagashira coupling of alkynes 10a and 10b with commercially available acid chloride 9 to give yno...
Scheme 3: Conjugate addition of primary amines 12a–f with ynones 11a and 11b. aFollowing concentration in vac...
Scheme 4: Cyclisation of precursors 13 to natural product analogues 14 using palladium- or copper-catalysed c...
Scheme 5: Use of an excess of DMEDA in the Cu-catalysed cyclisation of 13bb resulted in the generation of 14bg...
Figure 2: Growth of E. coli ESS with time in the presence of 200 μM of each compound. A) Natural product seri...
Figure 3: Growth of S. aureus 25923 with time in the presence of 200 μM of each compound. A) Natural product ...
Figure 4: OD520 (absorption corresponding to pyocyanin) normalised by the culture population (measured by OD6...
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
- Suzuki–Miyaura coupling reaction of bromobenzene with 5,7-di(Bpin)azulene, which in turn was formed via the exhaustive borylation of azulene with excess bis(pinacolato)diboron (B2pin2) [21]. Cyclocondensation of 5,7-diphenylazulene with formaldehyde produced 5 [22] under conditions similar to those used
Graphical Abstract
Figure 1: Examples of calix[n]arenes 1 and calix[4]azulenes 2–5.
Figure 2: Three major computed conformers of OPC4A; a: 1,2-alternate; b: cone and c: saddle.
Figure 3: Geometry-optimized (ωB97xD/6-31G(d)) and (ωB97xD/GenECP) structures, respectively, computed for lef...
Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source
- Tetsuaki Fujihara and
- Yasushi Tsuji
Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221
- coumarin derivative. Rhodium catalysts Carboxylation of aryl and alkenylboronic esters Aryl and alkenylboronic acids or their esters are of interest in organic synthesis because they are commonly used for C–C bond-forming reactions such as Pd-catalyzed Suzuki–Miyaura coupling reactions [50][51][52][53
Graphical Abstract
Scheme 1: Optimization of the Co-catalyzed carboxylation of 1a.
Scheme 2: Co-catalyzed carboxylation of propargyl acetates 1.
Scheme 3: Plausible reaction mechanism for the Co-catalyzed carboxylation of propargyl acetates 1.
Scheme 4: Optimization of the Co-catalyzed carboxylation of 3a.
Scheme 5: Co-catalyzed carboxylation of vinyl triflates 3.
Scheme 6: Co-catalyzed carboxylation of a sterically hindered aryl triflate 5.
Scheme 7: Optimization of the Co-catalyzed carboxylation of 7a.
Scheme 8: Scope of the reductive carboxylation of α,β-unsaturated nitriles 7.
Scheme 9: Scope of the carboxylation of α,β-unsaturated carboxamides 9.
Scheme 10: Optimization of the Co-catalyzed carboxylation of 11a.
Scheme 11: Scope of the carboxylation of allylarenes 11.
Scheme 12: Scope of the carboxylation of 1,4-diene derivatives 14.
Scheme 13: Plausible reaction mechanism for the Co-catalyzed C(sp3)–H carboxylation of allylarenes.
Scheme 14: Optimization of the Co-catalyzed carboxyzincation of 16a.
Scheme 15: Derivatization of the carboxyzincated product.
Scheme 16: Co-catalyzed carboxyzincation of alkynes 16.
Scheme 17: Plausible reaction mechanism for the Co-catalyzed carboxyzincation of alkynes 16.
Scheme 18: Co-catalyzed four-component coupling of alkynes 16, acrylates 18, CO2, and zinc.
Scheme 19: Proposed reaction mechanism for the Co-catalyzed four-component coupling.
Scheme 20: Visible-light-driven hydrocarboxylation of alkynes.
Scheme 21: Visible-light-driven synthesis of γ-hydroxybutenolides from ortho-ester-substituted aryl alkynes.
Scheme 22: One-pot synthesis of coumarines and 2-quinolones via hydrocarboxylation/alkyne isomerization/cycliz...
Scheme 23: Proposed reaction mechanism for the Co-catalyzed carboxylative cyclization of ortho-substituted aro...
Scheme 24: Rh-catalyzed carboxylation of arylboronic esters 25.
Scheme 25: Rh-catalyzed carboxylation of alkenylboronic esters 27.
Scheme 26: Plausible reaction mechanism for the Rh-catalyzed carboxylation of arylboronic esters 25.
Scheme 27: Ligand effect on the Rh-catalyzed carboxylation of 2-phenylpyridine 29a.
Scheme 28: Rh-catalyzed chelation-assisted C(sp2)–H bond carboxylation with CO2.
Scheme 29: Reaction mechanism for the Rh-catalyzed C(sp2)–H carboxylation of 2-pyridylarenes 29.
Scheme 30: Carboxylation of C(sp2)–H bond with CO2.
Scheme 31: Carboxylation of C(sp2)–H bond with CO2.
Scheme 32: Reaction mechanism for the Rh-catalyzed C(sp2)–H carboxylation of 2-arylphenols 34.
Scheme 33: Hydrocarboxylation of styrene derivatives with CO2.
Scheme 34: Hydrocarboxylation of α,β-unsaturated esters with CO2.
Scheme 35: Asymmetric hydrocarboxylation of α,β-unsaturated esters with CO2.
Scheme 36: Proposed reaction mechanism for the Rh-catalyzed hydrocarboxylation of C–C double bonds with CO2.
Scheme 37: Visible-light-driven hydrocarboxylation with CO2.
Scheme 38: Visible-light-driven Rh-catalyzed hydrocarboxylation of C–C double bonds with CO2.
Scheme 39: Optimization of reaction conditions on the Rh-catalyzed [2 + 2 + 2] cycloaddition of diyne 42a and ...
Scheme 40: [2 + 2 + 2] Cycloaddition of diyne and CO2.
Scheme 41: Proposed reaction pathways for the Rh-catalyzed [2 + 2 + 2] cycloaddition of diyne and CO2.
Synthesis and characterization of π–extended “earring” subporphyrins
- Haiyan Guan,
- Mingbo Zhou,
- Bangshao Yin,
- Ling Xu and
- Jianxin Song
Beilstein J. Org. Chem. 2018, 14, 1956–1960, doi:10.3762/bjoc.14.170
- 10.3762/bjoc.14.170 Abstract A π-extended “earring” subporphyrin 3 was synthesized from β,β′-diiodosubporphyrin and diboryltripyrrane via a Suzuki–Miyaura coupling and following oxidation. Its Pd complex 3Pd was also synthesized and both of the compounds were fully characterized by 1H NMR, MS and X-ray
- boron atom [25][26][27][28][29][30], meso- [31][32] and β-position [33][34][35]. By using the method developed by Osuka the β,β′-diborylsubporphyrins [36] can be obtained in high yields. A subsequent Suzuki–Miyaura coupling smoothly affords various β-aryl-substituted subporphyrins [37]. Alternatively
- cavities π-extended “earring” porphyrins through the aforementioned Suzuki–Miyaura coupling reaction and subsequent oxidation [38]. In this case β,β′-dibromo/tetrabromoporphyrins and diboryltripyrrane were applied as reactants. We discovered that both the π-extended “earring” porphyrins and the
Graphical Abstract
Scheme 1: Synthesis of “earring” subporphyrin and its Pd complex. Synthetic procedure: (i) Diboryltripyrrane ...
Figure 1: Partial 1H NMR spectrum of 3.
Figure 2: X-ray crystal structures of 3: a) top view; b) side view. Thermal ellipsoids are drawn at the 50% p...
Figure 3: Partial 1H NMR spectrum of 3Pd.
Figure 4: X-ray crystal structures of 3Pd: a) top view; b) side view. Thermal ellipsoids are at the 30% proba...
Figure 5: UV–vis/NIR spectra of 3 and 3Pd.
