Search for "C–C bond formations" in Full Text gives 19 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234
Graphical Abstract
Figure 1: (A) Structures of tetrasubstituted 5,10,15,20-tetraphenylporphyrin (TPP, 1), dodecasubstituted 2,3,...
Scheme 1: Reaction scheme for the synthesis of OET-xBrPPs and subsequent Ni(II) metalation.
Figure 2: Substrates used for the investigations for the Suzuki–Miyaura coupling reactions.
Scheme 2: Scope of arm-extended dodecasubstituted porphyrins synthesized via modification of the meso-para-ph...
Scheme 3: Scope of arm-extended dodecasubstituted porphyrins synthesized via reaction at the meso-meta-phenyl...
Scheme 4: Attempts of arm-extension of dodecasubstituted porphyrins at the meso-ortho-phenyl position.
Scheme 5: Borylation and subsequent Suzuki–Miyaura coupling of porphyrin 13.
Figure 3: View of the molecular structure of compounds 26 (top left) and 27 (top right) with atomic displacem...
Figure 4: Left: packing diagram of 27 viewed normal to the c-axis showing the channels in the lattice with th...
Figure 5: Left: view of part 0 2 in the molecular structure of the α2β2-atropisomer, 11 in the crystal, hydro...
Figure 6: Schematic representation of porphyrin 37 showing a doubly intercalated structure.
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. 2023, 19, 687–699, doi:10.3762/bjoc.19.50
Graphical Abstract
Figure 1: Biologically active agents and chiral ligands containing medium and large phostams, phostones, and ...
Figure 2: Synthetic strategies for the preparation of medium and large phostams, phostones, and phostines.
Scheme 1: Synthesis of 1,2-azaphosphepine 2-oxide, 1,2-azaphosphocine 2-oxide, 1,2-azaphosphepane 2-oxide, an...
Scheme 2: Synthesis of bis[1,2]oxaphosphepine 2-oxide from tert-butyl 2-(bis(allyloxy)phosphoryl)pent-4-enoat...
Scheme 3: Synthesis of 2-ethoxy-5H-benzo[f][1,2]oxaphosphepine 2-oxides from 2-allylphenyl ethyl vinylphospho...
Scheme 4: Synthesis of 2-ethoxy-3,6-dihydrobenzo[g][1,2]oxaphosphocine 2-oxides from 2-allylphenyl ethyl ally...
Scheme 5: Synthesis of benzothiophene-fused 2-hydroxy-1,2-oxaphosphecane 2-oxide from (4-allyl-2-(4-methylphe...
Scheme 6: Synthesis of benzothiophene-fused 2-hydroxy-1,2-oxaphosphecane 2-oxide from benzyl hydrogen ((4-all...
Scheme 7: Synthesis of benzothiophene-fused 2-hydroxy-1-oxa-2-phosphacycloundecane 2-oxide from benzyl hydrog...
Scheme 8: Synthesis of 5,6,7-trihydro-1,2-oxaphosphepine 2-oxide and its benzo derivatives from 3-bromobut-3-...
Scheme 9: Synthesis of thieno[2,3-d]pyrimidine-fused 2-hydroxy-1,2-oxaphosphonane 2-oxide from benzyl hydroge...
Scheme 10: Synthesis of 3-phenoxybenzo[f]pyreno[1,10-cd][1,2]oxaphosphepine 3-oxide from diphenyl pyren-1-ylph...
Scheme 11: Synthesis of 1,2-oxaphosphepane 2-oxides and 1,2-oxaphosphocane 2-oxide from hydrogen methyl hex-5-...
Scheme 12: Synthesis of 2-methoxy-1,2-oxaphosphinane 2-oxides, 1,2-oxaphosphepine 2-oxides, 1,2-oxaphosphepane...
Scheme 13: Synthesis of 1,2-azaphosphepane 2-oxide and its benzo derivatives from 5-bromohex-5-en-1-yl methylp...
Scheme 14: Synthesis of 4-phenyl-1,2-dihydronaphtho[2,1-c][1,2]oxaphosphinine 4-oxide and 1-phenyl-3,4-dihydro...
Scheme 15: Synthesis of 2-alkoxy-3,5-dimethylene-1,2-oxaphosphepane 2-oxides from dialkyl 2-bromo-1-methylethy...
Scheme 16: Synthesis of 14-methyl-2-phenoxy-1-oxa-2-phosphacyclotetradecane 2-oxide from phenyl hydrogen (12-h...
Scheme 17: Synthesis of 5-oxo-1,3,5-trihydrobenzo[f][1,2]azaphosphepine 2-oxides from 1,2-dihydro-4H-benzo[d][...
Scheme 18: Synthesis of 3-hydrobenzo[f][1,2]oxaphosphepin-5(4H)-one 2-oxides from 2-phenyl/alkoxy-4H-benzo[d][...
Scheme 19: Synthesis of bicyclic seven- and eight-membered phosphotones from cycloalk-2-enones and dimethyl ph...
Scheme 20: Synthesis of binaphthylene-fused phosphotones from (M)-2'-methyl-[1,1'-binaphthalen]-2-ol and pheny...
Scheme 21: Synthesis of bicyclic phosphotone from (1S,2R)-2-methyl-3-(phenylsulfonyl)cyclohept-3-en-1-ol and d...
Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1
Graphical Abstract
Scheme 1: The power of radical retrosynthesis and the tactic of divergent total synthesis.
Figure 1: Evolution of radical chemistry for organic synthesis.
Scheme 2: Divergent total synthesis of α-pyrone-diterpenoids (Baran).
Scheme 3: Divergent synthesis of pyrone diterpenoids by merged chemoenzymatic and radical synthesis (part I, ...
Scheme 4: Divergent synthesis of pyrone diterpenoids by merged chemoenzymatic and radical synthesis (part II,...
Scheme 5: Divergent synthesis of drimane-type hydroquinone meroterpenoids (Li).
Scheme 6: Divergent synthesis of natural products isolated from Dysidea avara (Lu).
Scheme 7: Divergent synthesis of kaurene-type terpenoids (Lei).
Scheme 8: Divergent synthesis of 6-oxabicyclo[3.2.1]octane meroterpenoids (Lou).
Scheme 9: Divergent synthesis of crinipellins by radical-mediated Dowd–Backwith rearrangement (Xie and Ding).
Scheme 10: Divergent total synthesis of Galbulimima alkaloids (Shenvi).
Scheme 11: Divergent synthesis of eburnane alkaloids (Qin).
Scheme 12: Divergent synthesis of Aspidosperma alkaloids (Boger).
Scheme 13: Photoredox based synthesis of (−)-FR901483 (160) and (+)-TAN1251C (162, Gaunt).
Scheme 14: Divergent synthesis of bipolamines (Maimone).
Scheme 15: Flow chemistry divergency between aporphine and morphinandione alkaloids (Felpin).
Scheme 16: Divergent synthesis of pyrroloazocine natural products (Echavarren).
Scheme 17: Using TEMPO to stabilize radicals for the divergent synthesis of pyrroloindoline natural products (...
Scheme 18: Radical pathway for preparation of lignans (Zhu).
Scheme 19: Divergent synthesis of DBCOD lignans (Lumb).
Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32
Graphical Abstract
Figure 1: Stabilizing interaction in the CF3CH2+ carbenium ion (top) and structure of the first observable fl...
Scheme 1: Isodesmic equations accounting for the destabilizing effect of the CF3 group. ΔE in kcal⋅mol−1, cal...
Scheme 2: Stabilizing effect of fluorine atoms by resonance electron donation in carbenium ions (δ in ppm).
Scheme 3: Direct in situ NMR observation of α-(trifluoromethyl)carbenium ion or protonated alcohols. Δδ = δ19...
Scheme 4: Reported 13C NMR chemical shifts for the α-(trifluoromethyl)carbenium ion 10c (δ in ppm).
Scheme 5: Direct NMR observation of α-(trifluoromethyl)carbenium ions in situ (δ in ppm).
Scheme 6: Illustration of the ion pair solvolysis mechanism for sulfonate 13f. YOH = solvent.
Figure 2: Solvolysis rate for 13a–i and 17.
Figure 3: Structures of allyl triflates 18 and 19 and allyl brosylate 20. Bs = p-BrC6H4SO2.
Figure 4: Structure of tosylate derivatives 21.
Figure 5: a) Structure of triflate derivatives 22. b) Stereochemistry outcomes of the reaction starting from (...
Scheme 7: Solvolysis reaction of naphthalene and anthracenyl derivatives 26 and 29.
Figure 6: Structure of bisarylated derivatives 34.
Figure 7: Structure of bisarylated derivatives 36.
Scheme 8: Reactivity of 9c in the presence of a Brønsted acid.
Scheme 9: Cationic electrocyclization of 38a–c under strongly acidic conditions.
Scheme 10: Brønsted acid-catalyzed synthesis of indenes 42 and indanes 43.
Scheme 11: Reactivity of sulfurane 44 in triflic acid.
Scheme 12: Solvolysis of triflate 45f in alcoholic solvents.
Scheme 13: Synthesis of labeled 18O-52.
Scheme 14: Reactivity of sulfurane 53 in triflic acid.
Figure 8: Structure of tosylates 56 and 21f.
Scheme 15: Resonance forms in benzylic carbenium ions.
Figure 9: Structure of pyrrole derivatives 58 and 59.
Scheme 16: Resonance structure 60↔60’.
Scheme 17: Ga(OTf)3-catalyzed synthesis of 3,3’- and 3,6’-bis(indolyl)methane from trifluoromethylated 3-indol...
Scheme 18: Proposed reaction mechanism.
Scheme 19: Metal-free 1,2-phosphorylation of 3-indolylmethanols.
Scheme 20: Superacid-mediated arylation of thiophene derivatives.
Scheme 21: In situ mechanistic NMR investigations.
Scheme 22: Proposed mechanisms for the prenyltransferase-catalyzed condensation.
Scheme 23: Influence of a CF3 group on the allylic SN1- and SN2-mechanism-based reactions.
Scheme 24: Influence of the CF3 group on the condensation reaction.
Scheme 25: Solvolysis of 90 in TFE.
Scheme 26: Solvolysis of allyl triflates 94 and 97 and isomerization attempt of 96.
Scheme 27: Proposed mechanism for the formation of 95.
Scheme 28: Formation of α-(trifluoromethyl)allylcarbenium ion 100 in a superacid.
Scheme 29: Lewis acid activation of CF3-substituted allylic alcohols.
Scheme 30: Bimetallic-cluster-stabilized α-(trifluoromethyl)carbenium ions.
Scheme 31: Reactivity of cluster-stabilized α-(trifluoromethyl)carbenium ions.
Scheme 32: α-(Trifluoromethyl)propargylium ion 122↔122’ generated from silyl ether 120 in a superacid.
Scheme 33: Formation of α-(trifluoromethyl)propargylium ions from CF3-substituted propargyl alcohols.
Scheme 34: Direct NMR observation of the protonation of some trifluoromethyl ketones in situ and the correspon...
Scheme 35: Selected resonance forms in protonated fluoroketone derivatives.
Scheme 36: Acid-catalyzed Friedel–Crafts reactions of trifluoromethyl ketones 143a,b and 147a–c.
Scheme 37: Enantioselective hydroarylation of CF3-substituted ketones.
Scheme 38: Acid-catalyzed arylation of ketones 152a–c.
Scheme 39: Reactivity of 156 in a superacid.
Scheme 40: Reactivity of α-CF3-substituted heteroaromatic ketones and alcohols as well as 1,3-diketones.
Scheme 41: Reactivity of 168 with benzene in the presence of a Lewis or Brønsted acid.
Scheme 42: Acid-catalyzed three-component asymmetric reaction.
Scheme 43: Anodic oxidation of amines 178a–c and proposed mechanism.
Scheme 44: Reactivity of 179b in the presence of a strong Lewis acid.
Scheme 45: Trifluoromethylated derivatives as precursors of trifluoromethylated iminium ions.
Scheme 46: Mannich reaction with trifluoromethylated hemiaminal 189.
Scheme 47: Suitable nucleophiles reacting with 192 after Lewis acid activation.
Scheme 48: Strecker reaction involving the trifluoromethylated iminium ion 187.
Scheme 49: Reactivity of 199 toward nucleophiles.
Scheme 50: Reactivity of 204a with benzene in the presence of a Lewis acid.
Scheme 51: Reactivity of α-(trifluoromethyl)-α-chloro sulfides in the presence of strong Lewis acids.
Scheme 52: Anodic oxidation of sulfides 213a–h and Pummerer rearrangement.
Scheme 53: Mechanism for the electrochemical oxidation of the sulfide 213a.
Scheme 54: Reactivity of (trifluoromethyl)diazomethane (217a) in HSO3F.
Figure 10: a) Structure of diazoalkanes 217a–c and b) rate-limiting steps of their decomposition.
Scheme 55: Deamination reaction of racemic 221 and enantioenriched (S)-221.
Scheme 56: Deamination reaction of labeled 221-d2. Elimination products were formed in this reaction, the yiel...
Scheme 57: Deamination reaction of 225-d2. Elimination products were also formed in this reaction in undetermi...
Scheme 58: Formation of 229 from 228 via 1,2-H-shift.
Scheme 59: Deamination reaction of 230. Elimination products were formed in this reaction, the yield of which ...
Scheme 60: Deamination of several diazonium ions. Elimination products were formed in these reactions, the yie...
Scheme 61: Solvolysis reaction mechanism of alkyl tosylates.
Scheme 62: Solvolysis outcome for the tosylates 248 and 249 in HSO3FSbF5.
Figure 11: Solvolysis rate of 248, 249, 252, and 253 in 91% H2SO4.
Scheme 63: Illustration of the reaction pathways. TsCl, pyridine, −5 °C (A); 98% H2SO4, 30 °C (B); 98% H2SO4, ...
Scheme 64: Proposed solvolysis mechanism for the aliphatic tosylate 248.
Scheme 65: Solvolysis of the derivatives 259 and 260.
Scheme 66: Solvolysis of triflate 261. SOH = solvent.
Scheme 67: Intramolecular Friedel–Crafts alkylations upon the solvolysis of triflates 264 and 267.
Scheme 68: α-CF3-enhanced γ-silyl elimination of cyclobutyltosylates 270a,b.
Scheme 69: γ-Silyl elimination in the synthesis of a large variety of CF3-substituted cyclopropanes. Pf = pent...
Scheme 70: Synthetic pathways to 281. aNMR yields.
Scheme 71: The cyclopropyl-substituted homoallylcyclobutylcarbenium ion manifold.
Scheme 72: Reactivity of CF3-substituted cyclopropylcarbinyl derivatives 287a–c. LG = leaving group.
Scheme 73: Reactivity of CF3-substituted cyclopropylcarbinyl derivatives 291a–c.
Scheme 74: Superacid-promoted dimerization or TFP.
Scheme 75: Reactivity of TFP in a superacid.
Scheme 76: gem-Difluorination of α-fluoroalkyl styrenes via the formation of a “hidden” α-RF-substituted carbe...
Scheme 77: Solvolysis of CF3-substituted pentyne 307.
Scheme 78: Photochemical rearrangement of 313.
Figure 12: Structure of 2-norbornylcarbenium ion 318 and argued model for the stabilization of this cation.
Figure 13: Structures and solvolysis rate (TFE, 25 °C) of the sulfonates 319–321. Mos = p-MeOC6H4SO2.
Scheme 79: Mechanism for the solvolysis of 323. SOH = solvent.
Scheme 80: Products formed by the hydrolysis of 328.
Scheme 81: Proposed carbenium ion intermediates in an equilibrium during the solvolysis of tosylates 328, 333,...
Beilstein J. Org. Chem. 2020, 16, 1006–1021, doi:10.3762/bjoc.16.90
Graphical Abstract
Scheme 1: Copper-catalysed ACA of organometallics to piperidones. A) addition of organozinc reagents; B) addi...
Scheme 2: Copper-catalysed ACA of alkenylalanes to N-substituted-2,3-dehydro-4-piperidones.
Scheme 3: Copper-catalysed asymmetric addition of dialkylzinc reagents to N-acyl-4-methoxypyridinium salts fo...
Scheme 4: Copper-catalysed ACA of organozirconium reagents to N-substituted 2,3-dehydro-4-piperidones and lac...
Scheme 5: Copper-catalysed ACA of Grignard reagents to chromones and coumarins and further derivatisation of ...
Scheme 6: Copper-catalysed ACA of Grignard reagents to N-protected quinolones.
Scheme 7: Copper-catalysed ACAs of organometallics to conjugated unsaturated lactams.
Scheme 8: Copper-catalysed ACA of Et2Zn to 5,6-dihydro-2-pyranone.
Scheme 9: Copper-catalysed ACA of Grignard reagents to pyranone and 5,6-dihydro-2-pyranone.
Scheme 10: Copper-catalysed AAA of an organozirconium reagent to heterocyclic acceptors.
Scheme 11: Copper-catalysed ring opening of an oxygen-bridged substrate with trialkylaluminium reagents.
Scheme 12: Copper-catalysed ring opening of oxabicyclic substrates with organolithium reagents (selected examp...
Scheme 13: Copper-catalysed ring opening of polycyclic meso hydrazines.
Scheme 14: Copper-catalysed ACA of Grignard reagents to alkenyl-substituted aromatic N-heterocycles.
Scheme 15: Copper-catalysed ACA of Grignard reagents to β-substituted alkenylpyridines.
Scheme 16: Copper-catalysed ACA of organozinc reagents to alkylidene Meldrum’s acids.
Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165
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.
Beilstein J. Org. Chem. 2019, 15, 256–278, doi:10.3762/bjoc.15.23
Graphical Abstract
Scheme 1: The oxidative radical ring-opening/cyclization of cyclopropane derivatives.
Scheme 2: Mn(OAc)3-mediated oxidative radical ring-opening and cyclization of MCPs with malonates.
Scheme 3: Mn(III)-mediated oxidative radical ring-opening and cyclization of MCPs with 1,3-dicarbonyl compoun...
Scheme 4: Heat-promoted ring-opening/cyclization of MCPs with elemental chalgogens.
Scheme 5: Copper(II) acetate-mediated oxidative radical ring-opening and cyclization of MCPs with diphenyl di...
Scheme 6: AIBN-promoted oxidative radical ring-opening and cyclization of MCPs with benzenethiol.
Scheme 7: AIBN-mediated oxidative radical ring-opening and cyclization of MCPs with diethyl phosphites.
Scheme 8: Organic-selenium induced radical ring-opening and cyclization of MCPs derivatives (cyclopropylaldeh...
Scheme 9: Copper(I)-catalyzed oxidative radical trifluoromethylation/ring-opening/cyclization of MCPs with To...
Scheme 10: Ag(I)-mediated trifluoromethylthiolation/ring-opening/cyclization of MCPs with AgSCF3.
Scheme 11: oxidative radical ring-opening and cyclization of MCPs with α-C(sp3)-–H of ethers.
Scheme 12: Oxidative radical ring-opening and cyclization of MCPs with aldehydes.
Scheme 13: Cu(I) or Fe(II)-catalyzed oxidative radical trifluoromethylation/ring-opening/cyclization of MCPs d...
Scheme 14: Rh(II)-catalyzed oxidative radical ring-opening and cyclization of MCPs.
Scheme 15: Ag(I)-catalyzed oxidative radical amination/ring-opening/cyclization of MCPs derivatives.
Scheme 16: Heating-promoted radical ring-opening and cyclization of MCP derivatives (arylvinylidenecyclopropan...
Scheme 17: Bromine radical-mediated ring-opening of alkylidenecyclopropanes.
Scheme 18: Fluoroalkyl (Rf) radical-mediated ring-opening of MCPs.
Scheme 19: Visible-light-induced alkylation/ring-opening/cyclization of cyclopropyl olefins with bromides.
Scheme 20: Mn(III)-mediated ring-opening and [3 + 3]-annulation of cyclopropanols and vinyl azides.
Scheme 21: Ag(I)-catalyzed oxidative ring-opening of cyclopropanols with quinones.
Scheme 22: Ag(I)-catalyzed oxidative ring-opening of cyclopropanols with heteroarenes.
Scheme 23: Cu(I)-catalyzed oxidative ring-opening/trifluoromethylation of cyclopropanols.
Scheme 24: Cu(I)-catalyzed oxidative ring-opening and trifluoromethylation/trifluoromethylthiolation of cyclop...
Scheme 25: Ag(I)-mediated oxidative ring-opening/fluorination of cyclopropanols with Selectfluor.
Scheme 26: Photocatalyzed ring-opening/fluorination of cyclopropanols with Selectfluor.
Scheme 27: Na2S2O8-promoted ring-opening/alkynylation of cyclopropanols with EBX.
Scheme 28: Ag(I)-catalyzed ring-opening and chlorination of cyclopropanols with aldehydes.
Scheme 29: Ag(I)-catalyzed ring-opening/alkynylation of cyclopropanols with EBX.
Scheme 30: Na2S2O8-promoted ring-opening/alkylation of cyclopropanols with acrylamides.
Scheme 31: Cyclopropanol ring-opening initiated tandem cyclization with acrylamides or 2-isocyanobiphenyls.
Scheme 32: Ag(II)-mediated oxidative ring-opening/fluorination of cyclopropanols with AgF2.
Scheme 33: Cu(II)-catalyzed ring-opening/fluoromethylation of cyclopropanols with sulfinate salts.
Scheme 34: Cu(II)-catalyzed ring-opening/sulfonylation of cyclopropanols with sulfinate salts.
Scheme 35: Na2S2O8-promoted ring-opening/arylation of cyclopropanols with propiolamides.
Scheme 36: The ring-opening and [3 + 2]-annulation of cyclopropanols with α,β-unsaturated aldehydes.
Scheme 37: Cu(II)-catalyzed ring-opening/arylation of cyclopropanols with aromatic nitrogen heterocyles.
Scheme 38: Ag(I)-catalyzed ring-opening and difluoromethylthiolation of cyclopropanols with PhSO2SCF2H.
Scheme 39: Ag(I)-catalyzed ring-opening and acylation of cyclopropanols with aldehydes.
Scheme 40: Aerobic oxidation ring-opening of cyclopropanols for the synthesis of 2-oxyranyl ketones.
Scheme 41: Aerobic oxidation ring-opening of cyclopropanols for the synthesis of linear enones.
Scheme 42: Aerobic oxidation ring-opening of cyclopropanols for the synthesis of metabolite.
Beilstein J. Org. Chem. 2017, 13, 895–902, doi:10.3762/bjoc.13.90
Graphical Abstract
Scheme 1: Envisaged general approach for the synthesis of the title compounds.
Scheme 2: Synthesis of 4-iodopyrazoles of type 3.
Scheme 3: Lithium–halogen exchange and subsequent carboxylation with iodopyrazoles 3a–d.
Scheme 4: Attempted cross-coupling reactions with 4-halopyrazoles 5 and 3a.
Scheme 5: Negishi couplings with 4-iodopyrazoles 3a,b.
Scheme 6: Formation of pyrazoloquinolizin-6-ium iodide 12 upon reaction of 3a with (phenylethynyl)zinc bromid...
Scheme 7: Prototropic tautomerism of compound 1a.
Figure 1: 1H NMR (in italics), 13C NMR and 15N NMR (in bold) chemical shifts of compound 9a (in CDCl3).
Beilstein J. Org. Chem. 2016, 12, 628–635, doi:10.3762/bjoc.12.61
Graphical Abstract
Figure 1: Parent and supported bifunctional thioureas used in this work.
Scheme 1: Reaction of nitrostyrene with diethyl malonate and 2-ethoxycarbonyl cyclopentanone.
Scheme 2: Reaction of nitrostyrenes with malonates and β-diketones.
Scheme 3: Reaction of nitrostyrenes with β-keto esters and β-dicarbonyl compounds.
Scheme 4: Reaction of nitrostyrenes with α-nitrocyclohexanone and ethyl α-nitropropionate.
Beilstein J. Org. Chem. 2015, 11, 2654–2660, doi:10.3762/bjoc.11.285
Graphical Abstract
Figure 1: Structure of PGI2 and beraprost (1).
Scheme 1: Retrosynthetic analysis of beraprost (1).
Scheme 2: Preparation of Michael precursors 7 and 8.
Scheme 3: First attempt at the synthesis of 2 from 6.
Scheme 4: Achievement of a formal synthesis of 2.
Beilstein J. Org. Chem. 2015, 11, 1412–1417, doi:10.3762/bjoc.11.152
Graphical Abstract
Figure 1: Structures of photopyrones 1–8, pseudopyronines 9–11, myxopyronin A (12) and corallopyronin A (13)....
Scheme 1: Proposed biosynthesis of photopyrone D (4) by PpyS from P. luminescens. The second deprotonation st...
Figure 2: Dimeric structure of modeled PpyS (A). Chain A (blue), chain B (red). 14 (surface, cyan) is covalen...
Figure 3: Phylogenetic tree (PHYML) composed of PpyS, its homologues and other known ketosynthases. Table S4 (...
Beilstein J. Org. Chem. 2015, 11, 568–575, doi:10.3762/bjoc.11.62
Graphical Abstract
Scheme 1: Photooxidation of the substrate and reductive quenching of the photocatalyst (left) vs photoreducti...
Scheme 2: Mechanism of the Markovnikov-type photocatalytic addition of methanol to 1,1-diphenylethylene (1) a...
Scheme 3: Intramolecular photocatalytic addition with substrate 3; reaction conditions: 3 (2 mM), Py (2 mM), ...
Scheme 4: Proposed mechanism of the anti-Markovnikov-type photocatalytic addition of methanol to 1,1-diphenyl...
Figure 1: Conversion of substrate 1 and formation of product 5 observed during photocatalysis with PDI in the...
Figure 2: Conversion of substrate 1 (black dashed) and formation of product 5 (red solid) observed during pho...
Figure 3: Spectra of PDI before (dotted black) and after excitation (red), then every 2 min until ground stat...
Scheme 5: Intramolecular additions of substrates 8 and 10 to demonstrate the effect of different electron den...
Beilstein J. Org. Chem. 2015, 11, 431–436, doi:10.3762/bjoc.11.49
Graphical Abstract
Figure 1: Thioxanthone (1a).
Scheme 1: Route to methoxyarenes 1d, 1f, and 1h.
Scheme 2: Ru-catalyzed C–H activation of thioxanthones. Conditions: 6 mol % RuH2(CO)(PPh3)3, toluene, 135 °C,...
Beilstein J. Org. Chem. 2013, 9, 1388–1396, doi:10.3762/bjoc.9.155
Graphical Abstract
Scheme 1: Sketch illustrating preparation of the Au@HS-CNC catalyst.
Figure 1: Au4f and S2p XPS spectra of the Au@HS-CNC (4.4 mol %) catalyst.
Figure 2: TEM pictures of the HS-NCC and Au@HS-CNC (4.4 mol %) catalyst (scale bar: 5 nm).
Figure 3: Thermogravimetric behavior of the Au@HS-CNC (4.4 mol %) catalyst (A) and CNC (B).
Figure 4: FT-IR spectra of CNC, HS-CNC, and Au@HS-CNC (4.4 mol %) catalyst.
Figure 5: Solid-state 13C NMR spectra of the CNC and Au@HS-CNC (4.4 mol %) catalyst.
Figure 6: Recycling test of Au@HS-CNC (4.4 mol %) catalyst for the three-component coupling of formaldehyde, ...
Beilstein J. Org. Chem. 2012, 8, 522–527, doi:10.3762/bjoc.8.59
Graphical Abstract
Figure 1: Synthetic route to transform oxyglycal I to a septanoside V.
Scheme 1: Reaction conditions: (i) NaOMe, PhMe, reflux, 8 h; (ii) methyl acrylate (for 3); tert-butyl acrylat...
Scheme 2: Reaction conditions: (i) phenylboronic acid (for 8); 4-methoxyphenylboronic acid (for 9); 3-methylp...
Scheme 3: Reaction conditions: (i) phenylacetylene (for 11); oct-1-yne (for 12); Pd(PPh3)2Cl2 (20 mol %), CuI...
Scheme 4: Reaction conditions: (i) Pd/C (10 %), H2, MeOH, rt, 24 h; (ii) NaBH4, MeOH, 0 °C to rt, 3 h.
Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103
Graphical Abstract
Scheme 1: Gold-catalyzed addition of alcohols.
Scheme 2: Gold-catalyzed cycloaddition of alcohols.
Scheme 3: Ionic liquids as the solvent in gold-catalyzed cycloaddition.
Scheme 4: Gold-catalyzed cycloaddition of diynes.
Scheme 5: Gold(I) chloride catalyzed cycloisomerization of 2-alkynyl-1,5-diols.
Scheme 6: Gold-catalyzed cycloaddition of glycols and dihydroxy compounds.
Scheme 7: Gold-catalyzed ring-opening of cyclopropenes.
Scheme 8: Gold-catalyzed intermolecular hydroalkoxylation of alkynes. PR3 = 41–45.
Scheme 9: Gold-catalyzed intramolecular 6-endo-dig cyclization of β-hydroxy-α,α-difluoroynones.
Scheme 10: Gold-catalyzed intermolecular hydroalkoxylation of non-activated olefins.
Scheme 11: Preparation of unsymmetrical ethers from alcohols.
Scheme 12: Expedient synthesis of dihydrofuran-3-ones.
Scheme 13: Catalytic approach to functionalized divinyl ketones.
Scheme 14: Gold-catalyzed glycosylation.
Scheme 15: Gold-catalyzed cycloaddition of aldehydes and ketones.
Scheme 16: Gold-catalyzed annulations of 2-(ynol)aryl aldehydes and o-alkynyl benzaldehydes.
Scheme 17: Gold-catalyzed addition of carboxylates.
Scheme 18: Dual-catalyzed rearrangement reaction of allenoates.
Scheme 19: Meyer–Schuster rearrangement of propargylic alcohols.
Scheme 20: Propargylic alcohol rearrangements.
Scheme 21: Gold-catalyzed synthesis of imines and amine alkylation.
Scheme 22: Hydroamination of allenes and allenamides.
Scheme 23: Gold-catalyzed inter- and intramolecular amination of alkynes and alkenes.
Scheme 24: Gold-catalyzed cycloisomerization of O-propioloyl oximes and β-allenylhydrazones.
Scheme 25: Intra- and intermolecular amination with ureas.
Scheme 26: Gold-catalyzed cyclization of ortho-alkynyl-N-sulfonylanilines and but-3-yn-1-amines.
Scheme 27: Gold-catalyzed piperidine ring synthesis.
Scheme 28: Ring expansion of alkylnyl cyclopropanes.
Scheme 29: Gold-catalyzed annulations of N-propargyl-β-enaminones and azomethine imines.
Scheme 30: Gold(I)-catalyzed cycloisomerization of aziridines.
Scheme 31: AuCl3/AgSbF6-catalyzed intramolecular amination of 2-(tosylamino)phenylprop-1-en-3-ols.
Scheme 32: Gold-catalyzed cyclization via a 7-endo-dig pathway.
Scheme 33: Gold-catalyzed synthesis of fused xanthines.
Scheme 34: Gold-catalyzed synthesis of amides and isoquinolines.
Scheme 35: Gold-catalyzed oxidative cross-coupling reactions of propargylic acetates.
Scheme 36: Gold-catalyzed nucleophilic addition to allenamides.
Scheme 37: Gold-catalyzed direct carbon–carbon bond coupling reactions.
Scheme 38: Gold-catalyzed C−H functionalization of indole/pyrrole heterocycles and non-activated arenes.
Scheme 39: Gold-catalyzed cycloisomerization of cyclic compounds.
Scheme 40: Gold-catalyzed cycloaddition of 1-aryl-1-allen-6-enes and propargyl acetates.
Scheme 41: Gold(I)-catalyzed cycloaddition with ligand-controlled regiochemistry.
Scheme 42: Gold(I)-catalyzed cycloaddition of dienes and enynes.
Scheme 43: Gold-catalyzed intramolecular cycloaddition of 3-alkoxy-1,5-enynes and 2,2-dipropargylmalonates.
Scheme 44: Gold-catalyzed intramolecular cycloaddition of 1,5-allenynes.
Scheme 45: Gold(I)-catalyzed cycloaddition of indoles.
Scheme 46: Gold-catalyzed annulation reactions.
Scheme 47: Gold–carbenoid induced cleavage of a sp3-hybridized C−H bond.
Scheme 48: Furan- and indole-based cascade reactions.
Scheme 49: Tandem process using aromatic alkynes.
Scheme 50: Gold-catalyzed cycloaddition of 1,3-dien-5-ynes.
Scheme 51: Gold-catalyzed cascade cyclization of diynes, propargylic esters, and 1,3-enynyl ketones.
Scheme 52: Tandem reaction of β-phenoxyimino ketones and alkynyl oxime ethers.
Scheme 53: Gold-catalyzed tandem cyclization of enynes, 2-(tosylamino)phenylprop-1-yn-3-ols, and allenoates.
Scheme 54: Cyclization of 2,4-dien-6-yne carboxylic acids.
Scheme 55: Gold(I)-catalyzed tandem cyclization approach to tetracyclic indolines.
Scheme 56: Gold-catalyzed tandem reactions of alkynes.
Scheme 57: Aminoarylation and oxyarylation of alkenes.
Scheme 58: Cycloaddition of 2-ethynylnitrobenzene with various alkenes.
Scheme 59: Gold-catalyzed tandem reactions of allenoates and alkynes.
Scheme 60: Gold-catalyzed asymmetric synthesis of 2,3-dihydropyrroles.
Scheme 61: Chiral [NHC–Au(I)]-catalyzed cyclization of enyne.
Scheme 62: Gold-catalyzed hydroaminations and hydroalkoxylations.
Scheme 63: Gold(I)-catalyzed asymmetric hydroalkoxylation of 1,3-dihydroxymethyl-2-alkynylbenzene chromium com...
Scheme 64: Gold-catalyzed synthesis of julolidine derivatives.
Scheme 65: Gold-catalyzed the synthesis of chiral fused heterocycles.
Scheme 66: Gold-catalyzed asymmetric reactions with 3,5-(t-Bu)2-4-MeO-MeOBIPHEP.
Scheme 67: Gold-catalyzed cyclization of o-(alkynyl) styrenes.
Scheme 68: Asymmetric gold(I)-catalyzed redox-neutral domino reactions of enynes.
Scheme 69: Gold(I)-catalyzed enantioselective polyene cyclization reaction.
Scheme 70: Gold(I)-catalyzed enantioselective synthesis of benzopyrans.
Scheme 71: Gold(I)-catalyzed enantioselective ring expansion of allenylcyclopropanols.
Beilstein J. Org. Chem. 2009, 5, No. 1, doi:10.3762/bjoc.5.1
Graphical Abstract
Scheme 1: Aza- and thia-substituted electron donors.
Scheme 2: Radical-polar crossover reaction of arenediazonium salts by TTF.
Scheme 3: Studies on the reductive radical cyclization of arenediazonium salt 16 by TDAE.
Scheme 4: Preparation of the arenediazonium salts 31a–d. Reagents and conditions: (a) 23, NaH, THF, 0 °C, 0.5...
Scheme 5: Cascade radical cyclizations of arenediazonium salts 42 and 44 by TDAE. Reagents and conditions: (a...
Scheme 6: TDAE-mediated radical based addition-elimination route to indoles.
Scheme 7: Cyclization of the arenediazonium salts 49b–d by TDAE. Reagents and conditions: (a) NOBF4, CH2Cl2, ...
Scheme 8: Cyclization of the arenediazonium salt 62 by TDAE. Reagents and conditions: (a) 2-Nitrobenzenesulfo...
Scheme 9: Mechanism for the formation of the tetracyclic sulfonamide 65.
Scheme 10: Possible mechanism for the formation of indole (63) and indole sulfonamide 64.
Beilstein J. Org. Chem. 2007, 3, No. 24, doi:10.1186/1860-5397-3-24
Graphical Abstract
Scheme 1: Microwave promoted ene reaction of ethyl trifluoropyruvate with α-methyl styrene.
Scheme 2: Thiourea catalysed ene reaction.
Scheme 3: Asymmetric carbonyl ene reaction mediated by chiral thiourea.
Scheme 4: Reaction between ethyl trifluoropyruvate and various alkenes.