Search for "sulfone" in Full Text gives 115 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2016, 12, 702–715, doi:10.3762/bjoc.12.70
Graphical Abstract
Figure 1: Selected piperazine-containing small-molecule pharmaceuticals.
Figure 2: Strategies for the synthesis of carbon-substituted piperazines.
Figure 3: The first α-lithiation of N-Boc-protected piperazines by van Maarseveen et al. in 2005 [37].
Figure 4: α-Lithiation of N-Boc-N’-tert-butyl piperazines by Coldham et al. in 2010 [38].
Figure 5: Diamine-free α-lithiation of N-Boc-piperazines by O’Brien, Campos, et al. in 2010 [40].
Figure 6: The first enantioselective α-lithiation of N-Boc-piperazines by McDermott et al. in 2008 [41].
Figure 7: Dynamic thermodynamic resolution of lithiated of N-Boc-piperazines by Coldham et al. in 2010 [38].
Figure 8: Enantioselective α-lithiation of N-Boc-N’-alkylpiperazines by O’Brien et al. in 2013 and 2016 [42,43].
Figure 9: Asymmetric α-functionalization of N-Boc-piperazines with Ph2CO by O’Brien et al. in 2016 [43].
Figure 10: A “chiral auxiliary” strategy toward enantiopure α-functionalized piperazines by O’Brien et al. 201...
Figure 11: Installation of methyl group at the α-position of piperazines by O’Brien et al. 2016 [43].
Figure 12: α-Lithiation trapping of C-substituted N-Boc-piperazines by O’Brien et al. 2016 [43].
Figure 13: Rh-catalyzed reactions of N-(2-pyridinyl)piperazines by Murai et al. in 1997 [52].
Figure 14: Ta-catalyzed hydroaminoalkylation of piperazines by Schafer et al. in 2013 [55].
Figure 15: Photoredox catalysis for α-C–H functionalization of piperazines by MacMillan et al. in 2011 and 201...
Figure 16: Copper-catalyzed aerobic C–H oxidation of piperazines by Touré, Sames, et al. in 2013 [67].
Figure 17: Free radical approach by Undheim et al. in 1994 [68].
Figure 18: Anodic oxidation approach by Nyberg et al. in 1976 [70].
Beilstein J. Org. Chem. 2016, 12, 16–21, doi:10.3762/bjoc.12.3
Graphical Abstract
Figure 1: 4H-chromene (1) and some of its biologically active derivatives.
Scheme 1: a) Preparation of 2-bromoallyl sulfones 2a,b; b) reaction of 2a with 4-chlorophenol and Cs2CO3; c) ...
Scheme 2: Base-mediated cyclization reaction of o-hydroxychalcone 7a and 2-bromoallyl sulfone 2a.
Scheme 3: Preparation of ortho-hydroxychalcones 7a–i.
Scheme 4: Synthesis of 4H-chromenes via base-mediated reactions of 7a–i and 2a,b. Reaction conditions: 7a–i (...
Scheme 5: A plausible mechanistic rationalization for the formation of 4H-chromene derivative 8aa from 7a and ...
Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273
Graphical Abstract
Figure 1: a) Structure of xenicin (1) and b) numbering of the xenicane skeleton according to Schmitz and van ...
Figure 2: Overview of selected Xenia diterpenoids according to the four subclasses [2-20]. The nine-membered carboc...
Figure 3: Representative members of the caryophyllenes, azamilides and Dictyota diterpenes.
Scheme 1: Proposed biosynthesis of Xenia diterpenoids (OPP = pyrophosphate, GGPP = geranylgeranyl pyrophospha...
Scheme 2: Direct synthesis of the nine-membered carbocycle as proposed by Schmitz and van der Helm (E = elect...
Scheme 3: The construction of E- or Z-cyclononenes.
Scheme 4: Total synthesis of racemic β-caryophyllene (22) by Corey.
Scheme 5: Total synthesis of racemic β-caryophyllene (22) by Oishi.
Scheme 6: Total synthesis of coraxeniolide A (10) by Leumann.
Scheme 7: Total synthesis of antheliolide A (18) by Corey.
Scheme 8: a) Synthesis of enantiomer 80, b) total syntheses of coraxeniolide A (10) and c) β-caryophyllene (22...
Scheme 9: Total synthesis of blumiolide C (11) by Altmann.
Scheme 10: Synthesis of a xeniolide F precursor by Hiersemann.
Scheme 11: Synthesis of the xenibellol (15) and the umbellacetal (114) core by Danishefsky.
Scheme 12: Proposed biosynthesis of plumisclerin A (118).
Scheme 13: Synthesis of the tricyclic core structure of plumisclerin A by Yao.
Scheme 14: Total synthesis of 4-hydroxydictyolactone (137) by Williams.
Scheme 15: Photoisomerization of 4-hydroxydictyolactone (137) to 4-hydroxycrenulide (138).
Scheme 16: The total synthesis of (+)-acetoxycrenulide (151) by Paquette.
Beilstein J. Org. Chem. 2015, 11, 2223–2241, doi:10.3762/bjoc.11.241
Graphical Abstract
Figure 1: Some ruthenium catalysts for metathesis reactions.
Scheme 1: Decomposition of methylidenes 1 and 2.
Scheme 2: Deactivation of G-HII in the presence of ethylene.
Scheme 3: Reaction between GI/GII and n-BuNH2.
Scheme 4: Reaction of GII with amines a–d.
Scheme 5: Amine-induced decomposition of GII methylidene 2.
Scheme 6: Amine-induced decomposition of GII in RCM conditions.
Scheme 7: Deactivation of methylidene 2 in the presence of pyridine.
Scheme 8: Reaction of G-HII with various amines.
Scheme 9: Formation of olefin 22 from styrene.
Scheme 10: Hypothetic deactivation pathway of G-HII.
Scheme 11: RCM of dienic pyridinium salts.
Scheme 12: Synthesis of polycyclic scaffolds using RCM.
Scheme 13: Enyne ring-closing metathesis.
Scheme 14: Synthesis of (R)-(+)-muscopyridine using a RCM strategy.
Scheme 15: Synthesis of a tris-pyrrole macrocycle.
Scheme 16: Synthesis of a bicyclic imidazole.
Scheme 17: RCM using Schrock’s catalyst 44.
Scheme 18: Synthesis of 1,6-pyrido-diazocine 46 by using a RCM.
Scheme 19: Synthesis of fused pyrimido-azepines through RCM.
Scheme 20: RCM involving alkenes containing various N-heteroaromatics.
Scheme 21: Synthesis of dihydroisoquinoline using a RCM.
Scheme 22: Formation of tricyclic compound 59.
Scheme 23: RCM in the synthesis of normuscopyridine.
Scheme 24: Synthesis of macrocycle 64.
Scheme 25: Synthesis of macrocycles possessing an imidazole group.
Scheme 26: Retrosynthesis of an analogue of erythromycin.
Scheme 27: Retrosynthesis of haminol A.
Scheme 28: CM involving 3-vinylpyridine 70 with 71 and vinylpyridine 70 with 73.
Scheme 29: Revised retrosynthesis of haminol A.
Scheme 30: CM between 78 and crotonaldehyde.
Scheme 31: Hypothesized deactivation pathway.
Scheme 32: CM involving an allyl sulfide containing a quinoline.
Scheme 33: CM involving allylic sulfide possessing a quinoxaline or a phenanthroline.
Scheme 34: CM between an acrylate and a 2-methoxy-5-bromo pyridine.
Scheme 35: Successful CM of an alkene containing a 2-chloropyridine.
Scheme 36: Variation of the substituent on the pyridine ring.
Scheme 37: CM involving alkenes containing a variety of N-heteroaromatics.
Beilstein J. Org. Chem. 2015, 11, 1833–1864, doi:10.3762/bjoc.11.199
Graphical Abstract
Figure 1: Ruthenium alkylidene catalysts used in RRM processes.
Figure 2: General representation of various RRM processes.
Figure 3: A general mechanism for RRM process.
Scheme 1: RRM of cyclopropene systems.
Scheme 2: RRM of cyclopropene with catalyst 2. (i) catalyst 2 (2.5 mol %), ethylene (24, 1 atm), (ii) toluene...
Scheme 3: RRM of various cyclopropene derivatives with catalyst 2. (i) catalyst 2 (2.5 mol %), CH2Cl2 (c = 0....
Scheme 4: RRM of substituted cyclopropene system with catalyst 2.
Scheme 5: RRM of cyclobutene system with catalyst 2.
Scheme 6: RRM approach to various bicyclic compounds.
Scheme 7: RRM approach to erythrina alkaloid framework.
Scheme 8: ROM–RCM sequence to lactone derivatives.
Scheme 9: RRM protocol towards the synthesis of lactone derivative 58.
Scheme 10: RRM protocol towards the asymmetric synthesis of asteriscunolide D (61).
Scheme 11: RRM strategy towards the synthesis of various macrolide rings.
Scheme 12: RRM protocol to dipiperidine system.
Scheme 13: RRM of cyclopentene system to generate the cyclohexene systems.
Scheme 14: RRM of cyclopentene system 74.
Scheme 15: RRM approach to compound 79.
Scheme 16: RRM approach to spirocycles.
Scheme 17: RRM approach to bicyclic dihydropyrans.
Scheme 18: RCM–ROM–RCM cascade using non strained alkenyl heterocycles.
Scheme 19: First ROM–RCM–ROM–RCM cascade for the synthesis of trisaccharide 97.
Scheme 20: RRM of cyclohexene system.
Scheme 21: RRM approach to tricyclic spirosystem.
Scheme 22: RRM approach to bicyclic building block 108a.
Scheme 23: ROM–RCM protocol for the synthesis of the bicyclo[3.3.0]octene system.
Scheme 24: RRM protocol to bicyclic enone.
Scheme 25: RRM protocol toward the synthesis of the tricyclic system 118.
Scheme 26: RRM approach toward the synthesis of the tricyclic enones 122a and 122b.
Scheme 27: Synthesis of tricyclic and tetracyclic systems via RRM protocol.
Scheme 28: RRM protocol towards the synthesis of tetracyclic systems.
Scheme 29: RRM of the propargylamino[2.2.1] system.
Scheme 30: RRM of highly decorated bicyclo[2.2.1] systems.
Scheme 31: RRM protocol towards fused tricyclic compounds.
Scheme 32: RRM protocol to functionalized tricyclic systems.
Scheme 33: RRM approach to functionalized polycyclic systems.
Scheme 34: Sequential RRM approach to functionalized tricyclic ring system 166.
Scheme 35: RRM protocol to functionalized CDE tricyclic ring system of schintrilactones A and B.
Scheme 36: Sequential RRM approach to 7/5 fused bicyclic systems.
Scheme 37: Sequential ROM-RCM protocol for the synthesis of bicyclic sugar derivatives.
Scheme 38: ROM–RCM sequence of the norbornene derivatives 186 and 187.
Scheme 39: RRM approach toward highly functionalized bridge tricyclic system.
Scheme 40: RRM approach toward highly functionalized tricyclic systems.
Scheme 41: Synthesis of hexacyclic compound 203 by RRM approach.
Scheme 42: RRM approach toward C3-symmetric chiral trimethylsumanene 209.
Scheme 43: Triquinane synthesis via IMDA reaction and RRM protocol.
Scheme 44: RRM approach to polycyclic compounds.
Scheme 45: RRM strategy toward cis-fused bicyclo[3.3.0]carbocycles.
Scheme 46: RRM protocol towards the synthesis of bicyclic lactone 230.
Scheme 47: RRM approach to spiro heterocyclic compounds.
Scheme 48: RRM approach to spiro heterocyclic compounds.
Scheme 49: RRM approach to regioselective pyrrolizidine system 240.
Scheme 50: RRM approach to functionalized bicyclic derivatives.
Scheme 51: RRM approach to tricyclic derivatives 249 and 250.
Scheme 52: RRM approach to perhydroindoline derivative and spiro system.
Scheme 53: RRM approach to bicyclic pyran derivatives.
Scheme 54: RRM of various functionalized oxanorbornene systems.
Scheme 55: RRM to assemble the spiro fused-furanone core unit. (i) 129, benzene, 55 °C, 3 days; (ii) Ph3P=CH2B...
Scheme 56: RRM protocol to norbornenyl sultam systems.
Scheme 57: Ugi-RRM protocol for the synthesis of 2-aza-7-oxabicyclo system.
Scheme 58: Synthesis of spiroketal systems via RRM protocol.
Scheme 59: RRM approach to cis-fused heterotricyclic system.
Scheme 60: RRM protocol to functionalized bicyclic systems.
Scheme 61: ROM/RCM/CM cascade to generate bicyclic scaffolds.
Scheme 62: RCM of ROM/CM product.
Scheme 63: RRM protocol to bicyclic isoxazolidine ring system.
Scheme 64: RRM approach toward the total synthesis of (±)-8-epihalosaline (300).
Scheme 65: Sequential RRM approach to decalin 304 and 7/6 fused 305 systems.
Scheme 66: RRM protocol to various fused carbocyclic derivatives.
Scheme 67: RRM to cis-hydrindenol derivatives.
Scheme 68: RRM protocol towards the cis-hydrindenol derivatives.
Scheme 69: RRM approach toward the synthesis of diversed polycyclic lactams.
Scheme 70: RRM approach towards synthesis of hexacyclic compound 324.
Scheme 71: RRM protocol to generate luciduline precursor 327 with catalyst 2.
Scheme 72: RRM protocol to key building block 330.
Scheme 73: RRM approach towards the synthesis of key intermediate 335.
Scheme 74: RRM protocol to highly functionalized spiro-pyran system 339.
Scheme 75: RRM to various bicyclic polyether derivatives.
Beilstein J. Org. Chem. 2015, 11, 1373–1378, doi:10.3762/bjoc.11.148
Graphical Abstract
Figure 1: Retrosynthetic approach to polycyclic sulfones.
Scheme 1: Preparation of the sulfone 6 via oxidation.
Scheme 2: Synthesis of alkenylated sulfone derivatives.
Scheme 3: Synthesis of 10 by RRM of 2a.
Scheme 4: Synthesis of 1b using RRM.
Scheme 5: RRM of the dipentenyl sulfone 2c.
Scheme 6: RRM of the dihexenyl sulfone 2d.
Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142
Graphical Abstract
Figure 1: General representation of cyclophanes.
Figure 2: cyclophanes one or more with heteroatom.
Figure 3: Metathesis catalysts 12–17 and C–C coupling catalyst 18.
Figure 4: Natural products containing the cyclophane skeleton.
Figure 5: Turriane family of natural products.
Scheme 1: Synthesis of [3]ferrocenophanes through Mannich reaction. Reagents and conditions: (i) excess HNMe2...
Scheme 2: Synthesis of cyclophanes through Michael addition. Reagents and conditions: (i) xylylene dibromide,...
Scheme 3: Synthesis of normuscopyridine analogue 37 through an oxymercuration–oxidation strategy. Reagents an...
Scheme 4: Synthesis of tribenzocyclotriyne 39 through Castro–Stephens coupling reaction. Reagents and conditi...
Scheme 5: Synthesis of cyclophane 43 through Glaser–Eglinton coupling. Reagents and conditions: (i) 9,10-bis(...
Scheme 6: Synthesis of the macrocyclic C-glycosyl cyclophane through Glaser coupling. Reagents and conditions...
Scheme 7: Synthesis of cyclophane-containing complex 49 through Glaser–Eglinton coupling reaction. Reagents a...
Scheme 8: Synthesis of cyclophane 53 through Glaser–Eglinton coupling. Reagents and conditions: (i) K2CO3, ac...
Figure 6: Cyclophanes 54–56 that have been synthesized through Glaser–Eglinton coupling.
Figure 7: Synthesis of tetrasubstituted [2.2]paracyclophane 57 and chiral cyclophyne 58 through Eglinton coup...
Scheme 9: Synthesis of cyclophane through Glaser–Hay coupling reaction. Reagents and conditions: (i) CuCl2 (1...
Scheme 10: Synthesis of seco-C/D ring analogs of ergot alkaloids through intramolecular Heck reaction. Reagent...
Scheme 11: Synthesis of muscopyridine 73 via Kumada coupling. Reagents and conditions: (i) 72, THF, ether, 20 ...
Scheme 12: Synthesis of the cyclophane 79 via McMurry coupling. Reagents and conditions: (i) 75, decaline, ref...
Scheme 13: Synthesis of stilbenophane 81 via McMurry coupling. Reagents and conditions: (i) TiCl4, Zn, pyridin...
Scheme 14: Synthesis of stilbenophane 85 via McMurry coupling. Reagents and conditions: (i) NBS (2 equiv), ben...
Figure 8: List of cyclophanes prepared via McMurry coupling reaction as a key step.
Scheme 15: Synthesis of paracyclophane by cross coupling involving Pd(0) catalyst. Reagents and conditions: (i...
Scheme 16: Synthesis of the cyclophane 112 via the pinacol coupling and 113 by RCM. Reagents and conditions: (...
Scheme 17: Synthesis of cyclophane derivatives 122a–c via Sonogoshira coupling. Reagents and conditions: (i) C...
Scheme 18: Synthesis of cyclophane 130 via Suzuki–Miyaura reaction as a key step. Reagents and conditions: (i)...
Scheme 19: Synthesis of the mycocyclosin via Suzuki–Miyaura cross coupling. Reagents and conditions: (i) benzy...
Scheme 20: Synthesis of cyclophanes via Wurtz coupling reaction Reagents and conditions: (i) PhLi, Et2O, C6H6,...
Scheme 21: Synthesis of non-natural glycophanes using alkyne metathesis. Reagents and conditions: (i) G-I (12)...
Figure 9: Synthesis of cyclophanes via ring-closing alkyne metathesis.
Scheme 22: Synthesis of crownophanes by cross-enyne metathesis. Reagents and conditions: (i) G-II (13), 5 mol ...
Scheme 23: Synthesis of (−)-cylindrocyclophanes A (156) and (−)-cylindrocyclophanes F (155). Reagents and cond...
Scheme 24: Synthesis of cyclophane 159 derivatives via SM cross-coupling and RCM. Reagents and conditions: (i)...
Scheme 25: Sexithiophene synthesis via cross metathesis. Reagents and conditions: (i) 161, Pd(PPh3)4, K2CO3, T...
Scheme 26: Synthesis of pyrrole-based cyclophane using enyne metathesis. Reagents and conditions: (i) Se, chlo...
Scheme 27: Synthesis of macrocyclic derivatives by RCM. Reagents and conditions: (i) G-I/G-II, CH2Cl2, 0.005 M...
Scheme 28: Synthesis of enantiopure β-lactam-based dienyl bis(dihydrofuran) 179. Reagents and conditions: (i) ...
Scheme 29: Synthesis of a [1.1.6]metaparacyclophane derivative 183 via SM cross coupling. Reagents and conditi...
Scheme 30: Synthesis of a [1.1.6]metaparacyclophane derivative 190 via SM cross coupling. Reagents and conditi...
Scheme 31: Template-promoted synthesis of cyclophanes involving RCM. Reagents and conditions: (i) acenaphthene...
Scheme 32: Synthesis of [3.4]cyclophane derivatives 200 via SM cross coupling and RCM. Reagents and conditions...
Figure 10: Examples for cyclophanes synthesized by RCM.
Scheme 33: Synthesis of the longithorone C framework assisted by fluorinated auxiliaries. Reagents and conditi...
Scheme 34: Synthesis of the longithorone framework via RCM. Reagents and conditions: (i) 213, NaH, THF, rt, 10...
Scheme 35: Synthesis of floresolide B via RCM as a key step. Reagents and conditions: (i) G-II (13, 0.1 equiv)...
Scheme 36: Synthesis of normuscopyridine (223) by the RCM strategy. Reagents and condition: (i) Mg, THF, hexen...
Scheme 37: Synthesis of muscopyridine (73) via RCM. Reagents and conditions: (i) 225, NaH, THF, 0 °C to rt, 1....
Scheme 38: Synthesis of muscopyridine (73) via RCM strategy. Reagents and conditions: (i) NaH, n-BuLi, 5-bromo...
Scheme 39: Synthesis of pyridinophane derivatives 223 and 245. Reagents and conditions: (i) PhSO2Na, TBAB, CH3...
Scheme 40: Synthesis of metacyclophane derivatives 251 and 253. Reagents and conditions: (i) 240, NaH, THF, rt...
Scheme 41: Synthesis of normuscopyridine and its higher analogues. Reagents and conditions: (i) alkenyl bromid...
Scheme 42: Synthesis of fluorinated ferrocenophane 263 via a [2 + 2] cycloaddition. Reagents and conditions: (...
Scheme 43: Synthesis of [2.n]metacyclophanes 270 via a [2 + 2] cycloaddition. Reagents and conditions: (i) Ac2...
Scheme 44: Synthesis of metacyclophane 273 by a [2 + 2 + 2] co-trimerization. Reagents and conditions: (i) [Rh...
Scheme 45: Synthesis of paracyclophane 276 via a [2 + 2 + 2] cycloaddition reaction. Reagents and conditions: ...
Scheme 46: Synthesis of cyclophane 278 via a [2 + 2 + 2] cycloaddition reaction. Reagents and conditions: (i) ...
Scheme 47: Synthesis of cyclophane 280 via a [2 + 2 + 2] cycloaddition. Reagents and conditions: (i) [(Rh(cod)(...
Scheme 48: Synthesis of taxane framework by a [2 + 2 + 2] cycloaddition. Reagents and conditions: (i) Cp(CO)2 ...
Scheme 49: Synthesis of cyclophane 284 and 285 via a [2 + 2 + 2] cycloaddition reaction. Reagents and conditio...
Scheme 50: Synthesis of pyridinophanes 293a,b and 294a,b via a [2 + 2 + 2] cycloaddition. Reagents and conditi...
Scheme 51: Synthesis of pyridinophanes 296 and 297 via a [2 + 2 + 2] cycloaddition. Reagents and conditions: (...
Scheme 52: Synthesis of triazolophane by a 1,3-dipolar cycloaddition. Reagents and conditions: (i) propargyl b...
Scheme 53: Synthesis of glycotriazolophane 309 by a click reaction. Reagents and conditions: (i) LiOH, H2O, Me...
Figure 11: Cyclophanes 310 and 311 prepared via click chemistry.
Scheme 54: Synthesis of cyclophane via the Dötz benzannulation. Reagents and conditions: (i) THF, 100 °C, 12 h...
Scheme 55: Synthesis of [6,6]metacyclophane by a Dötz benzannulation. Reagents and conditions: (i) THF, 100 °C...
Scheme 56: Synthesis of cyclophanes by a Dötz benzannulation. Reagents and conditions: (i) THF, 65 °C, 3 h; (i...
Scheme 57: Synthesis of muscopyridine (73) via an intramolecular DA reaction of ketene. Reagents and condition...
Scheme 58: Synthesis of bis[10]paracyclophane 336 via Diels–Alder reaction. Reagents and conditions: (i) DMAD,...
Scheme 59: Synthesis of [8]paracyclophane via DA reaction. Reagents and conditions: (i) maleic anhydride, 3–5 ...
Scheme 60: Biomimetic synthesis of (−)-longithorone A. Reagents and conditions: (i) Me2AlCl, CH2Cl2, −20 °C, 7...
Scheme 61: Synthesis of sporolide B (349) via a [4 + 2] cycloaddition reaction. Reagents and conditions: (i) P...
Scheme 62: Synthesis of the framework of (+)-cavicularin (352) via a [4 + 2] cycloaddition. Reagents and condi...
Scheme 63: Synthesis of oxazole-containing cyclophane 354 via Beckmann rearrangement. Reagents and conditions:...
Scheme 64: Synthesis of cyclophanes 360a–c via benzidine rearrangement. Reagents and conditions: (i) 356a–d, K2...
Scheme 65: Synthesis of cyclophanes 365a–c via benzidine rearrangement. Reagents and conditions: (i) BocNHNH2,...
Scheme 66: Synthesis of metacyclophane 367 via Ciamician–Dennstedt rearrangement. Reagents and conditions: (i)...
Scheme 67: Synthesis of cyclophane by tandem Claisen rearrangement and RCM as key steps. Reagents and conditio...
Scheme 68: Synthesis of cyclophane derivative 380. Reagents and conditions: (i) K2CO3, CH3CN, allyl bromide, r...
Scheme 69: Synthesis of metacyclophane via Cope rearrangement. Reagents and conditions: (i) MeOH, NaBH4, rt, 1...
Scheme 70: Synthesis of cyclopropanophane via Favorskii rearrangement. Reagents and conditions: (i) Br2, CH2Cl2...
Scheme 71: Cyclophane 389 synthesis via photo-Fries rearrangement. Reagents and conditions: (i) DMAP, EDCl/CHCl...
Scheme 72: Synthesis of normuscopyridine (223) via Schmidt rearrangement. Reagents and conditions: (i) ethyl s...
Scheme 73: Synthesis of crownophanes by tandem Claisen rearrangement. Reagents and conditions: (i) diamine, Et3...
Scheme 74: Attempted synthesis of cyclophanes via tandem Claisen rearrangement and RCM. Reagents and condition...
Scheme 75: Synthesis of muscopyridine via alkylation with 2,6-dimethylpyridine anion. Reagents and conditions:...
Scheme 76: Synthesis of cyclophane via Friedel–Craft acylation. Reagents and conditions: (i) CS2, AlCl3, 7 d, ...
Scheme 77: Pyridinophane 418 synthesis via Friedel–Craft acylation. Reagents and conditions: (i) 416, AlCl3, CH...
Scheme 78: Cyclophane synthesis involving the Kotha–Schölkopf reagent 421. Reagents and conditions: (i) NBS, A...
Scheme 79: Cyclophane synthesis involving the Kotha–Schölkopf reagent 421. Reagents and conditions: (i) BEMP, ...
Scheme 80: Cyclophane synthesis by coupling with TosMIC. Reagents and conditions: (i) (a) ClCH2OCH3, TiCl4, CS2...
Scheme 81: Synthesis of diaza[32]cyclophanes and triaza[33]cyclophanes. Reagents and conditions: (i) DMF, NaH,...
Scheme 82: Synthesis of cyclophane 439 via acyloin condensation. Reagents and conditions: (i) Na, xylene, 75%;...
Scheme 83: Synthesis of multibridged binuclear cyclophane 442 by aldol condensation. Reagents and conditions: ...
Scheme 84: Synthesis of various macrolactones. Reagents and conditions: (i) iPr2EtN, DMF, 77–83%; (ii) TBDMSCl...
Scheme 85: Synthesis of muscone and muscopyridine via Yamaguchi esterification. Reagents and conditions: (i) 4...
Scheme 86: Synthesis of [5]metacyclophane via a double elimination reaction. Reagents and conditions: (i) LiBr...
Figure 12: Cyclophanes 466–472 synthesized via Hofmann elimination.
Scheme 87: Synthesis of cryptophane via Baylis–Hillman reaction. Reagents and conditions: (i) methyl acrylate,...
Scheme 88: Synthesis of cyclophane 479 via double Chichibabin reaction. Reagents and conditions: (i) excess 478...
Scheme 89: Synthesis of cyclophane 483 via double Chichibabin reaction. Reagents and conditions: (i) 481, OH−;...
Scheme 90: Synthesis of cyclopeptide via an intramolecular SNAr reaction. Reagents and conditions: (i) TBAF, T...
Scheme 91: Synthesis of muscopyridine (73) via C-zip ring enlargement reaction. Reagents and conditions: (i) H...
Figure 13: Mechanism of the formation of compound 494.
Scheme 92: Synthesis of indolophanetetraynes 501a,b using the Nicholas reaction as a key step. Reagents and co...
Scheme 93: Synthesis of cyclophane via radical cyclization. Reagents and conditions: (i) cyclododecanone, phen...
Scheme 94: Synthesis of (−)-cylindrocyclophanes A (156) and (−)-cylindrocyclophanes F (155). Reagents and cond...
Scheme 95: Cyclophane synthesis via Wittig reaction. Reagents and conditions: (i) LiOEt (2.1 equiv), THF, −78 ...
Figure 14: Representative examples of cyclophanes synthesized via Wittig reaction.
Scheme 96: Synthesis of the [6]paracyclophane via isomerization of Dewar benzene. Reagents and conditions: (i)...
Beilstein J. Org. Chem. 2015, 11, 1105–1111, doi:10.3762/bjoc.11.124
Graphical Abstract
Scheme 1: BEDT-TTF and chiral derivatives.
Scheme 2: Synthesis of the chiral sulfones (S,S)-1 and (R,R)-1.
Figure 1: Molecular structure of (R,R)-1 (left) and (S,S)-1 (right) together with atom numbering scheme (H at...
Figure 2: Packing of (R,R)-1 in the bc plane (left) and detailed S···S interactions (only S3···S7 (−1+x, y, z...
Figure 3: Packing of (S,S)-1 in the ab plane (left) and detailed S···S intermolecular interactions within (hi...
Beilstein J. Org. Chem. 2015, 11, 576–582, doi:10.3762/bjoc.11.63
Graphical Abstract
Scheme 1: Hetero-Diels–Alder reaction of thiobenzophenone (1a) with dimethyl acetylenedicarboxylate (2a) [10].
Scheme 2: Synthesis of polycyclic thiopyrans via the hetero-Diels–Alder reaction/1,3-hydrogen shift sequence.
Figure 1: ORTEP Plot [19] of the molecular structure of 4b, drawn using 50% probability displacement ellipsoids.
Scheme 3: Reactions of aryl/hetaryl thioketones with methyl propiolate (Table 1).
Scheme 4: Oxidation of selected thiopyrans 4 and 5 to give the corresponding sulfones.
Figure 2: ORTEP Plot [19] of the molecular structure of one of the symmetry-independent molecules of 6d, drawn us...
Beilstein J. Org. Chem. 2014, 10, 2729–2737, doi:10.3762/bjoc.10.288
Graphical Abstract
Scheme 1: Synthesis of nanodiamond derivatives carrying primary amino groups. a) Δ, b) 18-crown-6, KI, c) BH3...
Figure 1: FTIR-spectra of annealed nanodiamond 2 (a), nitrile 4 (b) and amine 5 (c). As can be seen from the ...
Figure 2: FTIR spectra (left) of compounds 2 (a), 9 (b), 10 (c) and 11 (d). The formation of the sulfone grou...
Figure 3: Modified Kaiser test. a) Left: control, right: positive result; b) left: control, control with prem...
Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195
Graphical Abstract
Figure 1: Examples of phosphonamide reagents used in stereoselective synthesis.
Figure 2: Natural products and bioactive molecules synthesized using phosphonamide-based chemistry (atoms, bo...
Scheme 1: Olefination with cyclic phosphonamide anions, mechanistic rationale, and selected examples 27a–d [18].
Scheme 2: Asymmetric olefination with chiral phosphonamide anions and selected examples 31a–d [1,22].
Scheme 3: Synthesis of α-substituted phosphonic acids 33a–e by asymmetric alkylation of chiral phosphonamide ...
Scheme 4: Asymmetric conjugate additions of C2-symmetric chiral phosphonamide anions to cyclic enones, lacton...
Scheme 5: Asymmetric conjugate additions of P-chiral phosphonamide anions generated from 40a and 44a to cycli...
Scheme 6: Asymmetric cyclopropanation with chiral chloroallyl phosphonamide 47, mechanistic rationale, and se...
Scheme 7: Asymmetric cyclopropanation with chiral chloromethyl phosphonamide 28d [59].
Scheme 8: Stereoselective synthesis of cis-aziridines 57 from chiral chloroallyl phosphonamide 47a [62].
Scheme 9: Synthesis of phosphonamides by (A) Arbuzov reaction, (B) condensation of diamines with phosphonic a...
Figure 3: Original and revised structure of polyoxin A (69) [24-26].
Scheme 10: Synthesis of (E)-polyoximic acid (9) [24-26].
Figure 4: Key assembly strategy of acetoxycrenulide (10) [41,42].
Scheme 11: Total synthesis of (+)-acetoxycrenulide (10) [41,42].
Scheme 12: Synthesis squalene synthase inhibitor 19 by asymmetric sulfuration (A) and asymmetric alkylation (B...
Figure 5: Key assembly strategy of fumonisin B2 (20) and its tricarballylic acid fragment 105 [45,46].
Scheme 13: Final steps of the total synthesis of fumonisin B2 (20) [45,46].
Figure 6: Selected examples of two subclasses of β-lactam antibiotics – carbapenems (111 and 112) and trinems...
Scheme 14: Synthesis of tricyclic β-lactam antibiotic 123 [97].
Scheme 15: Total synthesis of (−)-anthoplalone (8) [56].
Figure 7: Protein tyrosine phosphatase (PTP) inhibitors 130, 131 and model compounds 16, 132 and 133 [68].
Scheme 16: Synthesis of model PTP inhibitors 16a,b [68].
Scheme 17: Synthesis of aziridine hydroxamic acid 17 as MMP inhibitor [63].
Scheme 18: Synthesis of methyl jasmonate (11) [48].
Figure 8: Structures of nudiflosides A (137) and D (13) [49].
Scheme 19: Total synthesis of the pentasubstituted cyclopentane core 159 of nudiflosides A (151) and D (13) an...
Figure 9: L-glutamic acid (161) and constrained analogues [57,124].
Scheme 20: Stereoselective synthesis of DCG-IV (162) [57].
Scheme 21: Stereoselective synthesis of mGluR agonist 21 [124].
Figure 10: Key assembly strategy of berkelic acid (15) [43].
Scheme 22: Total synthesis of berkelic acid (15) [43].
Figure 11: Key assembly strategy of jerangolid A (22) and ambruticin S (14) [27,28].
Scheme 23: Final assembly steps in the total synthesis of jerangolid A [27].
Scheme 24: Key assembly steps in the total synthesis of ambruticin S (14) [28].
Figure 12: General steroid construction strategy based on conjugate addition of 212 to cyclopentenone 48, exem...
Scheme 25: Total synthesis of estrone (12) [44].
Beilstein J. Org. Chem. 2014, 10, 1023–1031, doi:10.3762/bjoc.10.102
Graphical Abstract
Figure 1: Structures of kigamicin B and aclacinomycin A as representative examples for antineoplastic glycoco...
Scheme 1: RCM-isomerization approach to L-amicetal 4 and alternative CM approaches to L-amicetose.
Scheme 2: Two step desilylation–acetal hydrolysis.
Scheme 3: Deprotection of 11 and 12 to L-amicetose derivative 16.
Scheme 4: Synthesis of a cinerulose-TBS ether 22.
Scheme 5: Deprotection of 24.
Beilstein J. Org. Chem. 2013, 9, 2422–2433, doi:10.3762/bjoc.9.280
Graphical Abstract
Figure 1: Chiral gold(I) complexes employed in 1,3-DC involving azomethine ylides.
Scheme 1: 1,3-DC of azlactone 5a and NPM.
Scheme 2: General 1,3-DC between azlactones 5 with maleimides.
Scheme 3: Formation of the amide 8aa.
Figure 2: Positive non-linear effects (NLE) observed in 1,3-DC of azlactone 7aa and NPM.
Figure 3: Main geometrical features and relative Gibbs free energies (in kcal mol−1 at 298 K) of complexes [(S...
Figure 4: Main geometrical features and relative Gibbs free energies (in kcal mol−1) of the less energetic tr...
Scheme 4: Reaction Gibbs free energy associated with the 1,3-DC of 5aa and NPM catalyzed by (Sa)-Binap gold d...
Scheme 5: ΔG calculation for the recovery of the catalytic active species.
Scheme 6: 1,3-DC of azlactone 10 and tert-butyl acrylate.
Figure 5: (A) Schematic representation of the model gold(I) ylides. (B) HOMO of the ylides and expansion orbi...
Figure 6: Main geometrical features and relative Gibbs free energies (in kcal mol−1 at 298 K) of complexes [{(...
Figure 7: Main geometrical features and relative Gibbs free energies (in kcal mol−1) of the less energetic tr...
Scheme 7: Reduction of heterocycle 7aa under different conditions.
Scheme 8: Double 1,3-DC to give polycycle 15.
Scheme 9: Reaction between 7aa and nitrostyrene.
Beilstein J. Org. Chem. 2013, 9, 2137–2146, doi:10.3762/bjoc.9.251
Graphical Abstract
Scheme 1: Reaction intermediates, resulting products, and model cations.
Scheme 2: Sn(IV)-catalyzed isomerization of nitronic esters.
Scheme 3: Thermal rearrangement of nitronic esters 2 and 3.
Scheme 4: Thermal rearrangement of nitronic esters 21a, 21b and 22b.
Scheme 5: Thermal reactions of nitronic esters 5, 7, and 26a–d.
Scheme 6: General transition state for the [3,3]-sigmatropic rearrangement of O-allyl nitronic esters.
Scheme 7: Thermal rearrangement of nitronic ester 30.
Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243
Graphical Abstract
Figure 1: a) Structural features and b) selected examples of non-natural congeners.
Scheme 1: Synthesis of isoindole 18.
Scheme 2: Staining amines with 1,4-diketone 19 (R = H).
Figure 2: Representative members of the indolocarbazole alkaloid family.
Figure 3: Staurosporine (26) bound to the adenosine-binding pocket [19] (from pdb1stc).
Figure 4: Structure of imatinib (34) and midostaurin (35).
Scheme 3: Biosynthesis of staurosporine (26).
Scheme 4: Wood’s synthesis of K-252a via the common intermediate 48.
Scheme 5: Synthesis of 26, 27, 49 and 50 diverging from the common intermediate 48.
Figure 5: Selected members of the cytochalasan alkaloid family.
Scheme 6: Biosynthesis of chaetoglobosin A (57) [56].
Scheme 7: Synthesis of cytochalasin D (70) by Thomas [63].
Scheme 8: Synthesis of L-696,474 (78).
Scheme 9: Synthesis of aldehyde 85 (R = TBDPS).
Scheme 10: Synthesis of (+)-aspergillin PZ (79) by Tanis.
Figure 6: Representative Berberis alkaloids.
Scheme 11: Proposed biosynthetic pathway to chilenine (93).
Scheme 12: Synthesis of magallanesine (97) by Danishefsky [84].
Scheme 13: Kurihara’s synthesis of magallanesine (85).
Scheme 14: Proposed biosynthesis of 113, 117 and 125.
Scheme 15: DNA lesion caused by aristolochic acid I (117) [102].
Scheme 16: Snieckus’ synthesis of piperolactam C (131).
Scheme 17: Synthesis of aristolactam BII (104).
Figure 7: Representative cularine alkaloids.
Scheme 18: Proposed biosynthesis of 136.
Scheme 19: The syntheses of 136 and 137 reported by Castedo and Suau.
Scheme 20: Synthesis of 136 by Couture.
Figure 8: Representative isoindolinone meroterpenoids.
Scheme 21: Postulated biosynthetic pathway for the formation of 156 (adopted from George) [143].
Scheme 22: Synthesis of stachyflin (156) by Katoh [144].
Figure 9: Selected examples of spirodihydrobenzofuranlactams.
Scheme 23: Synthesis of stachybotrylactam I (157).
Scheme 24: Synthesis of pestalachloride A (193) by Schmalz.
Scheme 25: Proposed mechanism for the BF3-catalyzed metal-free carbonyl–olefin metathesis [149].
Scheme 26: Preparation of the isoindoline core of muironolide A (204).
Scheme 27: Proposed biosynthesis of 208.
Scheme 28: Model for the biosynthesis of 215 and 217.
Scheme 29: Synthesis of lactonamycin (215) and lactonamycin Z (217).
Figure 10: Hetisine alkaloids 225–228.
Scheme 30: Biosynthetic proposal for the formation of the hetisine core [167].
Scheme 31: Synthesis of nominine (225).
Beilstein J. Org. Chem. 2013, 9, 1931–1935, doi:10.3762/bjoc.9.228
Graphical Abstract
Figure 1: Structure of symbiodinolide (1).
Scheme 1: Our previous synthesis of the C79–C96 fragment 7.
Scheme 2: Retrosynthetic analysis of the C79–C97 fragment 8.
Scheme 3: Synthesis of aldehyde 20.
Scheme 4: Synthesis of PT-sulfones 23 and 24.
Scheme 5: Synthesis of the C79–C97 fragment 27.
Beilstein J. Org. Chem. 2013, 9, 1813–1818, doi:10.3762/bjoc.9.211
Graphical Abstract
Scheme 1: Synthesis of ethyl diazoacetate (1).
Figure 1: Schematic representation of the microreactor setup.
Figure 2: Univariate optimization using 30 s, 15 °C and 1.5 equiv NaNO2 as standard.
Figure 3: 2D-Contour plots of the multivariate optimization.
Figure 4: Phase separation using a Flow-Liquid–Liquid-Extraction module (FLLEX) directly coupled to the micro...
Beilstein J. Org. Chem. 2013, 9, 1419–1425, doi:10.3762/bjoc.9.159
Graphical Abstract
Scheme 1: Synthesis of a conformationally constrained bicyclic sulfone, and application as an inhibitor of an...
Figure 1: X-ray structure of 3a.
Figure 2: Assignment of major and minor conformations of 3a; A: DFT-calculated conformers; B: Collected 1H NM...
Beilstein J. Org. Chem. 2013, 9, 1269–1277, doi:10.3762/bjoc.9.143
Graphical Abstract
Scheme 1: Representative C–P bond-forming reactions.
Scheme 2: General equation of homolytic substitution.
Scheme 3: Addition of diphenyl(triphenylstannyl)phosphine.
Scheme 4: Addition of diphenyl(trimethylstannyl)phosphine.
Scheme 5: Plausible mechanism of addition of R3Sn–PPh2.
Scheme 6: Addition of tetraorganodiphosphines to phenylacetylene.
Scheme 7: Plausible mechanism of anti-diphosphination.
Scheme 8: Radical diphosphination for synthesizing fluorescent material.
Scheme 9: Mechanism of thiophosphination with diphenyl(organosulfanyl)phosphine.
Scheme 10: Thiophosphination with S-thiophosphinyl O-ethyl dithiocarbonate.
Scheme 11: Photoinduced selenophosphination of allenes.
Scheme 12: Photoinduced tellurophosphination.
Scheme 13: Decarboxylative phosphorylation of carboxylic acid derivatives.
Scheme 14: Plausible mechanism of decarboxylative phosphorylation.
Scheme 15: Radical phosphination of PTOC esters with white phosphorus.
Scheme 16: Plausible mechanism of radical phosphination (Si = (Me3Si)3Si).
Scheme 17: Stereoselective phosphination leading to (S,S)-aminophosphine derivative.
Figure 1: Calculated reaction profile of homolytic substitution between Ph• and Me3Sn–PPh2 at the B2-PLYP-D/T...
Scheme 18: Phosphination with retention of axial chirality.
Scheme 19: Chemodivergent phosphination.
Scheme 20: Bis(phosphoryl)-bridged biphenyls by radical phosphination.
Scheme 21: Bis(phosphoryl)-bridged ladder triphenylene by radical phosphination.
Scheme 22: Photoinduced phosphination of perfluoroalkyl iodides with tetraphenyldiphosphine.
Scheme 23: Ti(III)-mediated radical phosphination of organic bromides with white phosphorus.
Beilstein J. Org. Chem. 2013, 9, 974–982, doi:10.3762/bjoc.9.112
Graphical Abstract
Scheme 1: Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and β-...
Scheme 2: Plausible mechanistic pathways for the formation of 1,2-trans-thioglycoside and β-glycosyl thiol.
Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61
Graphical Abstract
Scheme 1: Key radical step in the total synthesis of (–)-dendrobine.
Scheme 2: Radical cascade in the total synthesis of (±)-13-deoxyserratine (ACCN = 1,1'-azobis(cyclohexanecarb...
Scheme 3: Formation of the complete skeleton of (±)-fortucine.
Scheme 4: Model radical sequence for the synthesis of quadrone.
Scheme 5: Radical cascade using the Barton decarboxylation.
Scheme 6: Simplified mechanism for the xanthate addition to alkenes.
Scheme 7: Synthesis of β-lactam derivatives.
Scheme 8: Sequential additions to three different alkenes (PhthN = phthalimido).
Scheme 9: Key cascade in the total synthesis of (±)-matrine (43).
Scheme 10: Synthesis of complex tetralones.
Scheme 11: Synthesis of functionalised azaindoline and indole derivatives.
Scheme 12: Synthesis of thiochromanones.
Scheme 13: Synthesis of complex benzothiepinones. Conditions: 1) CF3COOH; 2) RCHO / AcOH (PMB = p-methoxybenzy...
Scheme 14: Formation and capture of a cyclic nitrone.
Scheme 15: Synthesis of bicyclic cyclobutane motifs.
Scheme 16: Construction of the CD rings of steroids.
Scheme 17: Rapid assembly of polyquinanes.
Scheme 18: Formation of a polycyclic structure via an allene intermediate.
Scheme 19: A polycyclic structure via the alkylative Birch reduction.
Scheme 20: Synthesis of polycyclic pyrimidines and indoline structures.
Scheme 21: Construction of a trans-decalin derivative.
Scheme 22: Multiple uses of a chloroacetonyl xanthate.
Scheme 23: A convergent route to spiroketals.
Scheme 24: A modular approach to 3-arylpiperidines.
Scheme 25: A convergent route to cyclopentanols and to functional allenes.
Scheme 26: Allylation and vinylation of a xanthate and an iodide.
Scheme 27: Vinyl epoxides as allylating agents.
Scheme 28: Radical allylations using allylic alcohol derivatives.
Scheme 29: Synthesis of variously substituted lactams.
Scheme 30: Nickel-mediated synthesis of unsaturated lactams.
Scheme 31: Total synthesis of (±)-3-demethoxy-erythratidinone.
Scheme 32: Generation and capture of an iminyl radical from an oxime ester.
Beilstein J. Org. Chem. 2013, 9, 278–302, doi:10.3762/bjoc.9.34
Graphical Abstract
Scheme 1: Variation of substrates for carbomagnesiation and carbozincation in this article.
Scheme 2: Copper-catalyzed arylmagnesiation and allylmagnesiation of alkynyl sulfone.
Scheme 3: Copper-catalyzed four-component reaction of alkynyl sulfoxide with alkylzinc reagent, diiodomethane...
Scheme 4: Rhodium-catalyzed reaction of aryl alkynyl ketones with arylzinc reagents.
Scheme 5: Allylmagnesiation of propargyl alcohol, which provides the anti-addition product.
Scheme 6: Negishi’s total synthesis of (Z)-γ-bisabolene by allylmagnesiation.
Scheme 7: Iron-catalyzed syn-carbomagnesiation of propargylic or homopropargylic alcohol.
Scheme 8: Mechanism of iron-catalyzed carbomagnesiation.
Scheme 9: Regio- and stereoselective manganese-catalyzed allylmagnesiation.
Scheme 10: Vinylation and alkylation of arylacetylene-bearing hydroxy group.
Scheme 11: Arylmagnesiation of (2-pyridyl)silyl-substituted alkynes.
Scheme 12: Synthesis of tamoxifen from 2g.
Scheme 13: Controlling regioselectivity of carbocupration by attaching directing groups.
Scheme 14: Rhodium-catalyzed carbozincation of ynamides.
Scheme 15: Synthesis of 4-pentenenitriles through carbometalation followed by aza-Claisen rearrangement.
Scheme 16: Uncatalyzed carbomagnesiation of cyclopropenes.
Scheme 17: Iron-catalyzed carbometalation of cyclopropenes.
Scheme 18: Enantioselective carbozincation of cyclopropenes.
Scheme 19: Copper-catalyzed facially selective carbomagnesiation.
Scheme 20: Arylmagnesiation of cyclopropenes.
Scheme 21: Enantioselective methylmagnesiation of cyclopropenes without catalyst.
Scheme 22: Copper-catalyzed carbozincation.
Scheme 23: Enantioselective ethylzincation of cyclopropenes.
Scheme 24: Nickel-catalyzed ring-opening aryl- and alkenylmagnesiation of a methylenecyclopropane.
Scheme 25: Reaction mechanism.
Scheme 26: Nickel-catalyzed carbomagnesiation of arylacetylene and dialkylacetylene.
Scheme 27: Nickel-catalyzed carbozincation of arylacetylenes and its application to the synthesis of tamoxifen....
Scheme 28: Bristol-Myers Squibb’s nickel-catalyzed phenylzincation.
Scheme 29: Iron/NHC-catalyzed arylmagnesiation of aryl(alkyl)acetylene.
Scheme 30: Iron/copper-cocatalyzed alkylmagnesiation of aryl(alkyl)acetylenes.
Scheme 31: Iron-catalyzed hydrometalation.
Scheme 32: Iron/copper-cocatalyzed arylmagnesiation of dialkylacetylenes.
Scheme 33: Chromium-catalyzed arylmagnesiation of alkynes.
Scheme 34: Cobalt-catalyzed arylzincation of alkynes.
Scheme 35: Cobalt-catalyzed formation of arylzinc reagents and subsequent arylzincation of alkynes.
Scheme 36: Cobalt-catalyzed benzylzincation of dialkylacetylene and aryl(alkyl)acetylenes.
Scheme 37: Synthesis of estrogen receptor antagonist.
Scheme 38: Cobalt-catalyzed allylzincation of aryl-substituted alkynes.
Scheme 39: Silver-catalyzed alkylmagnesiation of terminal alkyne.
Scheme 40: Proposed mechanism of silver-catalyzed alkylmagnesiation.
Scheme 41: Zirconium-catalyzed ethylzincation of terminal alkenes.
Scheme 42: Zirconium-catalyzed alkylmagnesiation.
Scheme 43: Titanium-catalyzed carbomagnesiation.
Scheme 44: Three-component coupling reaction.
Scheme 45: Iron-catalyzed arylzincation reaction of oxabicyclic alkenes.
Scheme 46: Reaction of allenyl ketones with organomagnesium reagent.
Scheme 47: Regio- and stereoselective reaction of a 2,3-allenoate.
Scheme 48: Three-component coupling reaction of 1,2-allenoate, organozinc reagent, and ketone.
Scheme 49: Proposed mechanism for a rhodium-catalyzed arylzincation of allenes.
Scheme 50: Synthesis of skipped polyenes by iterative arylzincation/allenylation reaction.
Scheme 51: Synthesis of 1,4-diorganomagnesium compound from 1,2-dienes.
Scheme 52: Synthesis of tricyclic compounds.
Scheme 53: Manganese-catalyzed allylmagnesiation of allenes.
Scheme 54: Copper-catalyzed alkylmagnesiation of 1,3-dienes and 1,3-enynes.
Scheme 55: Chromium-catalyzed methallylmagnesiation of 1,6-diynes.
Scheme 56: Chromium-catalyzed allylmagnesiation of 1,6-enynes.
Scheme 57: Proposed mechanism of the chromium-catalyzed methallylmagnesiation.
Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225
Graphical Abstract
Figure 1: Loschmidt’s structure proposal for benzene (1) (Scheme 181 from [3]) and the corresponding modern stru...
Figure 2: The first isolated bisallenes.
Figure 3: Carbon skeletons of selected bisallenes discussed in this review.
Scheme 1: The preparation of 1,2,4,5-hexatetraene (2).
Scheme 2: The preparation of a conjugated bisallene by the DMS-protocol.
Scheme 3: Preparation of the 3-deuterio- and 3,4-dideuterio derivatives of 24.
Scheme 4: A versatile method to prepare alkylated conjugated bisallenes and other allenes.
Scheme 5: A preparation of 3,4-dimethyl-1,2,4,5-hexatetraene (38).
Scheme 6: A (C6 + 0)-approach to 1,2,4,5-hexatetraene (2).
Scheme 7: The preparation of a fully alkylated bisallenes from a 2,4-hexadiyne-1,6-diol diacetate.
Scheme 8: The preparation of the first phenyl-substituted conjugated bisallenes 3 and 4.
Scheme 9: Selective hydrogenation of [5]cumulenes to conjugated bisallenes: another (C6 + 0)-route.
Scheme 10: Aryl-substituted conjugated bisallenes by a (C3 + C3)-approach.
Scheme 11: Hexaphenyl-1,2,4,5-hexatetraene (59) by a (C3 + C3)-approach.
Scheme 12: An allenation route to conjugated bisallenes.
Scheme 13: The preparation of 3,4-difunctionalized conjugated bisallenes.
Scheme 14: Problems during the preparation of sulfur-substituted conjugated bisallenes.
Scheme 15: The preparation of 3,4-dibromo bisallenes.
Scheme 16: Generation of allenolates by an oxy-Cope rearrangement.
Scheme 17: A linear trimerization of alkynes to conjugated bisallenes: a (C2 + C2 + C2)-protocol.
Scheme 18: Preparation of a TMS-substituted conjugated bisallene by a C3-dimerization route.
Scheme 19: A bis(trimethylsilyl)bisallene by a C3-coupling protocol.
Scheme 20: The rearrangement of highly substituted benzene derivatives into their conjugated bisallenic isomer...
Scheme 21: From fully substituted benzene derivatives to fully substituted bisallenes.
Scheme 22: From a bicyclopropenyl to a conjugated bisallene derivative.
Scheme 23: The conversion of a bismethylenecyclobutene into a conjugated bisallene.
Scheme 24: The preparation of monofunctionalized bisallenes.
Scheme 25: Preparation of bisallene diols and their cyclization to dihydrofurans.
Scheme 26: A 3,4-difunctionalized conjugated bisallene by a C3-coupling process.
Scheme 27: Preparation of a bisallenic diketone by a coupling reaction.
Scheme 28: Sulfur and selenium-substituted bisallenes by a [2.3]sigmatropic rearrangement.
Scheme 29: The biallenylation of azetidinones.
Scheme 30: The preparation of a fully ferrocenylated conjugated bisallene.
Scheme 31: The first isomerization of a 1,5-hexadiyne to a 1,2,4,5-hexatetraene.
Scheme 32: The preparation of alkynyl-substituted bisallenes by a C3-dimerization protocol.
Scheme 33: Preparation of another completely ferrocenylated bisallene.
Scheme 34: The cyclization of 1,5-hexadiyne (129) to 3,4-bismethylenecyclobutene (130) via 1,2,4,5-hexatetraen...
Scheme 35: Stereochemistry of the thermal cyclization of bisallenes to bismethylenecyclobutenes.
Scheme 36: Bisallene→bismethylenecyclobutene ring closures in the solid state.
Scheme 37: A bisallene cyclization/dimerization reaction.
Scheme 38: A selection of Diels–Alder additions of 1,2,4,5-hexatetraene with various double-bond dienophiles.
Scheme 39: The stereochemistry of the [2 + 4] cycloaddition to conjugated bisallenes.
Scheme 40: Preparation of azetidinone derivatives from conjugated bisallenes.
Scheme 41: Cycloaddition of heterodienophiles to a conjugated bisallene.
Scheme 42: Addition of triple-bond dienophiles to conjugated bisallenes.
Scheme 43: Sulfur dioxide addition to conjugated bisallenes.
Scheme 44: The addition of a germylene to a conjugated bisallene.
Scheme 45: Trapping of conjugated bisallenes with phosphinidenes.
Scheme 46: The cyclopropanantion of 1,2,4,5-hexatetraene (2).
Scheme 47: Photochemical reactions involving conjugated bisallenes.
Scheme 48: Base-catalyzed isomerizations of conjugated bisallenes.
Scheme 49: Ionic additions to a conjugated bisallene.
Scheme 50: Oxidation reactions of a conjugated bisallene.
Scheme 51: The mechanism of oxidation of the bisallene 24.
Scheme 52: CuCl-catalyzed cyclization of 1,2,4,5-hexatetraene (2).
Scheme 53: The conversion of conjugated bisallenes into cyclopentenones.
Scheme 54: Oligomerization of a conjugated bisallene by nickel catalysts.
Scheme 55: Generation of 1,2,5,6-heptatetraene (229) as a reaction intermediate.
Scheme 56: The preparation of a stable derivative of 1,2,5,6-heptatetraene.
Scheme 57: A bisallene with a carbonyl group as a spacer element.
Scheme 58: The first preparation of 1,2,6,7-octatetraene (242).
Scheme 59: Preparation of 1,2,6,7-octatetraenes by (C4 + C4)-coupling of enynes.
Scheme 60: Preparation of 1,2,6,7-octatetraenes by (C4 + C4)-coupling of homoallenyl bromides.
Scheme 61: Preparation of 1,2,6,7-octatetraenes by alkylation of propargylic substrates.
Scheme 62: Preparation of two highly functionalized 1,2,6,7-octatetraenes.
Scheme 63: Preparation of several higher α,ω-bisallenes.
Scheme 64: Preparation of different alkyl derivatives of α,ω-bisallenes.
Scheme 65: The preparation of functionalized 1,2,7,8-nonatetraene derivatives.
Scheme 66: Preparation of functionalized α,ω-bisallenes.
Scheme 67: The preparation of an α,ω-bisallene by direct homologation of an α,ω-bisalkyne.
Scheme 68: The gas-phase pyrolysis of 4,4-dimethyl-1,2,5,6-heptatetraene (237).
Scheme 69: Gas-phase pyrolysis of 1,2,6,7-octatetraene (242).
Scheme 70: The cyclopropanation of 1,2,6,7-octatetraene (242).
Scheme 71: Intramolecular cyclization of 1,2,6,7-octatetraene derivatives.
Scheme 72: The gas-phase pyrolysis of 1,2,7,8-nonatetraene (265) and 1,2,8,9-decatetraene (266).
Scheme 73: Rh-catalyzed cyclization of a functionalized 1,2,7,8-nonatetraene.
Scheme 74: A triple cyclization involving two different allenic substrates.
Scheme 75: Bicyclization of keto derivatives of 1,2,7,8-nonatetraene.
Scheme 76: The preparation of complex organic compounds from functionalized bisallenes.
Scheme 77: Cycloisomerization of an α,ω-bisallene containing a C9 tether.
Scheme 78: Organoborane polymers from α,ω-bisallenes.
Scheme 79: Preparation of trans- (337) and cis-1,2,4,6,7-octapentaene (341).
Scheme 80: The preparation of 4-methylene-1,2,5,6-heptatetraene (349).
Scheme 81: The preparation of acetylenic bisallenes.
Scheme 82: The preparation of derivatives of hydrocarbon 351.
Scheme 83: The construction of macrocyclic alleno-acetylenes.
Scheme 84: Preparation and reactions of 4,5-bismethylene-1,2,6,7-octatetraene (365).
Scheme 85: Preparation of 1,2-bis(propadienyl)benzene (370).
Scheme 86: The preparation of 1,4-bis(propadienyl)benzene (376).
Scheme 87: The preparation of aromatic and heteroaromatic bisallenes by metal-mediated coupling reactions.
Scheme 88: Double cyclization of an aromatic bisallene.
Scheme 89: Preparation of an allenic [15]paracyclophane by a ring-closing metathesis reaction of an aromatic α...
Scheme 90: Preparation of a macrocyclic ring system containing 1,4-bis(propadienyl)benzene units.
Scheme 91: Preparation of copolymers from 1,4-bis(propadienyl)benzene (376).
Scheme 92: A boration/copolymerization sequence of an aromatic bisallene and an aromatic bisacetylene.
Scheme 93: Formation of a layered aromatic bisallene.
Figure 4: The first members of the semicyclic bisallene series.
Scheme 94: Preparation of the first bis(vinylidene)cyclobutane derivative.
Scheme 95: Dimerization of strain-activated cumulenes to bis(vinylidene)cyclobutanes.
Scheme 96: Photodimerization of two fully substituted butatrienes in the solid state.
Scheme 97: Preparation of the two parent bis(vinylidene)cyclobutanes.
Scheme 98: The preparation of 1,3-bis(vinylidene)cyclopentane and its thermal isomerization.
Scheme 99: The preparation of the isomeric bis(vinylidene)cyclohexanes.
Scheme 100: Bi- and tricyclic conjugated bisallenes.
Scheme 101: A selection of polycyclic bisallenes.
Scheme 102: The first endocyclic bisallenes.
Figure 5: The stereochemistry of 1,2,6,7-cyclodecatetraene.
Scheme 103: The preparation of several endocyclic bisallenes.
Scheme 104: Synthesis of diastereomeric derivatives of 1,2,6,7-cyclodecatetraene.
Scheme 105: Preparation of a derivative of 1,2,8,9-cyclotetradecatetraene.
Scheme 106: The preparation of keto derivatives of cyclic bisallenes.
Scheme 107: The preparation of cyclic biscumulenic ring systems.
Scheme 108: Cyclic bisallenes in natural- and non-natural-product chemistry.
Scheme 109: The preparation of iron carbonyl complexes from cyclic bisallenes.
Figure 6: A selection of unknown exocyclic bisallenes that should have interesting chemical properties.
Scheme 110: The thermal isomerization of 1,2-diethynylcyclopropanes and -cyclobutanes.
Scheme 111: Intermediate generation of a cyclooctapentaene.
Scheme 112: Attempted preparation of a cyclodecahexaene.
Scheme 113: The thermal isomerization of 1,5,9-cyclododecatriyne (511) into [6]radialene (514).
Scheme 114: An isomerization involving a diketone derived from a conjugated bisallene.
Scheme 115: Typical reaction modes of heteroorganic bisallenes.
Scheme 116: Generation and thermal behavior of acyclic hetero-organic bisallenes.
Scheme 117: Generation of bis(propadienyl)thioether.
Scheme 118: The preparation of a bisallenic sulfone and its thermal isomerization.
Scheme 119: Bromination of the bisallenic sulfone 535.
Scheme 120: Metalation/hydrolysis of the bisallenic sulfone 535.
Scheme 121: Aromatic compounds from hetero bisallenes.
Scheme 122: Isomerization/cyclization of bispropargylic ethers.
Scheme 123: The preparation of novel aromatic systems by base-catalyzed isomerization of bispropargyl ethers.
Scheme 124: The isomerization of bisacetylenic thioethers to bicyclic thiophenes.
Scheme 125: Aromatization of macrocyclic bispropargylic sulfides.
Scheme 126: Preparation of ansa-compounds from macrocyclic bispropargyl thioethers.
Scheme 127: Alternate route for cyclization of a heterorganic bisallene.
Scheme 128: Multiple isomerization/cyclization of “double” bispropargylic thioethers.
Scheme 129: Preparation of a bisallenyl disulfide and its subsequent bicyclization.
Scheme 130: Thermal cyclization of a bisallenyl thiosulfonate.
Scheme 131: Some reactions of heteroorganic bisallenes with two sulfur atoms.
Scheme 132: Further methods for the preparation of heteroorganic bisallenes.
Scheme 133: Cyclization reactions of heteroorganic bisallenes.
Scheme 134: Thermal cycloadditions of bisallenic tertiary amines.
Scheme 135: Cyclization of a bisallenic tertiary amine in the presence of a transition-metal catalyst.
Scheme 136: A Pauson–Khand reaction of a bisallenic ether.
Scheme 137: Formation of a 2:1adduct from two allenic substrates.
Scheme 138: A ring-forming silastannylation of a bisallenic tertiary amine.
Scheme 139: A three-component cyclization involving a heterorganic bisallene.
Scheme 140: Atom-economic construction of a complex organic framework from a heterorganic α,ω-bisallene.
Beilstein J. Org. Chem. 2012, 8, 1710–1720, doi:10.3762/bjoc.8.195
Graphical Abstract
Figure 1: Important heterocycles containing pyrazolidine or pyrazoline structures.
Figure 2: X-ray crystal structure of racemic 4a (25% thermal ellipsoids).
Figure 3: X-ray crystal structure of racemic 4n (25% thermal ellipsoids).
Figure 4: The X-ray crystal structure of chiral compound 4s (40% thermal ellipsoids).
Beilstein J. Org. Chem. 2012, 8, 1400–1405, doi:10.3762/bjoc.8.162
Graphical Abstract
Figure 1: Related compounds of eletriptan hydrobromide.
Scheme 1: Synthetic route of eletriptan hydrobromide. Reagents and conditions: (i) Acetic anhydride, TEA, DMF...
Scheme 2: Dimerization of 13. Reagents and conditions: (i) NaH, THF, 30–35 °C, 2 h; 11.6% yield after column ...
Scheme 3: Formation of the isomers 3 and 4. Reagents and conditions: (i) Aqueous hydrogen peroxide, methanol,...
Scheme 4: Synthesis of impurity 5. Reagents and conditions: (i) Acetic anhydride, TEA, DMF, 90–100 °C; (ii) p...
Scheme 5: Debromination of 9 to 6. Reagents and conditions: Palladium on carbon, ethanol, ca. 7 bar, 25–30 °C...
Scheme 6: Formation of 7. Reagents, conditions: (i) (a) K2CO3, methanol, reflux, 2 days; 40% yield after colu...
Scheme 7: Synthesis of the tetracyclic compound 7. Reagents and conditions: (i) aqueous hydrogen peroxide, wa...