Search for "Mannich reaction" in Full Text gives 72 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2016, 12, 139–143, doi:10.3762/bjoc.12.15
Graphical Abstract
Scheme 1: Overall strategy.
Scheme 2: Boc-protected aminoalcohols used as inputs in a diastereoselective Ugi reaction.
Beilstein J. Org. Chem. 2015, 11, 1973–1984, doi:10.3762/bjoc.11.213
Graphical Abstract
Figure 1: (a) Schematic representation of the vicinal σC−H→σ*C−X interaction by double-bond/no-bond resonance...
Figure 2: Schematic representation of stereoelectronic effects (a) hyperconjugation, (b) homohyperconjugation...
Figure 3: Schematic representation of possible homoanomeric interactions in six-membered saturated heterocycl...
Figure 4: Structure of compounds 1 to 8.
Scheme 1: Proposed reaction mechanism for the synthesis of piperidones by the Mannich reaction. The substitue...
Scheme 2: For 6, R1 = R2 = H, for 7, R1 = H, R2 = CH3, for 8, R1 = R2 = CH3.
Figure 5: (a) Favored conformation for compound 1, determined by nOe effect, (b) t-ROESY spectrum of 1 record...
Figure 6: (a) Preferred conformation of 4 determined by nOe, (b) t-ROESY spectrum of 4 recorded at 500 MHz in...
Figure 7: (a) ORTEP diagram of 1. The thermal ellipsoids are drawn at the 30% probability level for all atoms...
Figure 8: (a) ORTEP diagrams of 6 and 7. The thermal ellipsoids are drawn at the 30% probability level for al...
Figure 9: (a) 1JC,H coupling constant of 3, 5, 6, and 8. (b) Plot of the population analysis versus 1JC,H (sl...
Scheme 3: Representation of the nN→σ*C–H(7)eq interaction. The interaction energy is 0.55 kcal/mol at the ωB9...
Figure 10: Distances between N(3) and C(7) for 3, 5, 6, and 7 measured in the structures obtained by XRD.
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. 2014, 10, 1914–1918, doi:10.3762/bjoc.10.199
Graphical Abstract
Scheme 1: The hypermodified nucleoside queuosine (Q) and the synthetic targets of preQ1 bases 1 to 3 with com...
Scheme 2: Synthesis of [15N1,15N3,H215N(C2)]-preQ1 base (1). a) CH3ONa (10 equiv) CH3OH, reflux, 10 h, RP C18...
Scheme 3: Synthesis of [15N9]-preQ1 base (2). a) [15N]-KCN (1 equiv), Na2CO3, H2O, pH 9, 80 °C, 3 h, then roo...
Scheme 4: Synthesis of [H215N(C7')] preQ1 base (3). a) K2CO3 (1.5 equiv), DMF, 70 °C, 14 h, 47%. b) Dess–Mart...
Figure 1: Comparison of 1H NMR spectra of the preQ1 bases 1, 2 and 3 with complementary 15N labeling patterns...
Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179
Graphical Abstract
Figure 1: Selected chemical modifications of natural ribose or 2'-deoxyribose nucleosides leading to the deve...
Scheme 1: (a) Classical Mannich reaction; (b) general structures of selected hydrogen active components and s...
Scheme 2: Reagents and reaction conditions: i. H2O or H2O/EtOH, 60–100 °C, 7 h–10 d; ii. H2, Pd/C or PtO2; ii...
Scheme 3: Reagents and reaction conditions: i. H2O, 90 °C, overnight.
Scheme 4: Reagents and reaction conditions: i. AcOH, H2O, 60 °C, 12 h-5 d; ii. AcOH, H2O, 60 °C, 8 h.
Scheme 5: Reagents and reaction conditions: i. CuBr, THF, reflux, 0.5 h; ii. n-Bu4NF·3H2O, THF, rt, 2 h.
Scheme 6: Reagents and reaction conditions: i. [bmim][PF6], 80 °C, 5–8 h.
Scheme 7: Reagents and reaction conditions: i. EtOH, reflux, 24 h.
Scheme 8: Reagents and reaction conditions: i. NaOAc, H2O, 95 °C, 1–16 h; ii. NaOAc, H2O, 95 °C, 1 h.
Scheme 9: Reagents and reaction conditions: i. a. 37% aq HCl, MeOH; b. NaOAc, 1,4-dioxane, H2O, 100 °C, overn...
Scheme 10: Reagents and reaction conditions: i. DMAP, DCC, MeOH, rt, 1 h.
Scheme 11: The Kabachnik–Fields reaction.
Scheme 12: Reagents and reaction conditions: i. 60 °C, 3 h; ii. 80 °C, 2 h.
Scheme 13: The four-component Ugi reaction.
Scheme 14: Reagents and reaction conditions: i. MeOH, rt, 2–3 d, yields not given.
Scheme 15: Reagents and reaction conditions: i. MeOH/CH2Cl2 (1:1), rt, 24 h, yield not given; ii. 6 N aq HCl, ...
Scheme 16: Reagents and reaction conditions: i. MeOH/H2O, rt, 26 h; ii. aq AcOH, reflux, 50%; iii. reversed ph...
Scheme 17: Reagents and reaction conditions: i. MeOH, rt, 24 h; ii. HCl, MeOH, 0 °C to rt, 6 h, then H2O, rt, ...
Scheme 18: Reagents and reaction conditions: i. DMF/Py/MeOH (1:1:1), rt, 48 h; ii. 10% HCl/MeOH, rt, 30 min.
Scheme 19: Reagents and reaction conditions (R = CH3 or H): i. CH2Cl2/MeOH (2:1), 35–40 °C, 2 d; ii. HF/pyridi...
Scheme 20: Reagents and reaction conditions: i. MeOH, 76%; ii. 80% aq TFA, 100%.
Scheme 21: Reagents and reaction conditions: i. EtOH, rt, 72 h; ii. Zn, aq NaH2PO4, THF, rt, 1 week; then 80% ...
Scheme 22: Reagents and reaction conditions: i. EtOH, rt, 48 h, then silica gel chromatography, 33% for 57 (30...
Scheme 23: Reagents and reaction conditions: i. [bmim]BF4, 80 °C, 4 h; ii. [bmim]BF4, 80 °C, 3 h; iii. [bmim]BF...
Scheme 24: Reagents and reaction conditions: i. [bmim]BF4, 80 °C.
Scheme 25: Reagents and reaction conditions: i. H3PW12O40 (2 mol %), EtOH, 50 °C, 2–15 h; ii. H3PW12O40 (2 mol...
Scheme 26: General scheme of the Biginelli reaction.
Scheme 27: Reagents and reaction conditions: i. EtOH, reflux.
Scheme 28: Reagents and reaction conditions: i. Bu4N+HSO4−, diethylene glycol, 120 °C, 1.5–3 h.
Scheme 29: Reagents and reaction conditions: i. BF3·Et2O, CuCl, AcOH, THF, 65 °C, 24 h; ii. Yb(OTf)3, THF, ref...
Scheme 30: Reagents and reaction conditions: TCT (10 mol %), rt: i. 100 min; ii. 150 min; iii. 140 min.
Scheme 31: Reagents and reaction conditions: i. EtOH, microwave irradiation (300 W), 10 min; ii. EtOH, 75 °C, ...
Scheme 32: The Hantzsch reaction.
Scheme 33: Reagents and reaction conditions: TCT (10 mol %), rt, 80–150 min.
Scheme 34: Reagents and reaction conditions: i. Yb(OTf)3, THF, 90 °C, 12 h; ii. 4 Å molecular sieves, EtOH, 90...
Scheme 35: Reagents and reaction conditions: i. MeOH, 50 °C, 48 h.
Scheme 36: Reagents and reaction conditions: i. MeOH, 25 °C, 5 d.
Scheme 37: Bu4N+HSO4−, diethylene glycol, 80 °C, 1–2 h.
Scheme 38: The three-component carbopalladation of dienes on the example of buta-1,3-diene.
Scheme 39: Reagents and reaction conditions: i. 5 mol % Pd(dba)2, Bu4NCl, ZnCl2, acetonitrile or DMSO, 80 °C o...
Scheme 40: Reagents and reaction conditions: i. 2.5 mol % Pd2(dba)3, tris(2-furyl)phosphine, K2CO3, MeCN or DM...
Scheme 41: Reagents and reaction conditions: i. 2.5 mol % Pd2(dba)3, tris(2-furyl)phosphine, K2CO3, MeCN or DM...
Scheme 42: The three-component Bucherer–Bergs reaction.
Scheme 43: Reagents and reaction conditions: i. MeOH, H2O, 70 °C, 4.5 h; ii. (1) H2, 5% Pd/C, MeOH, 55 °C, 5 h...
Scheme 44: Reagents and reaction conditions: i. pyridine, MgSO4, 100 °C, 28 h, N2; ii. DMF, 70–90 °C, 22–30 h,...
Scheme 45: Reagents and reaction conditions: i. Montmorillonite K-10 clay, microwave irradiation (600 W), 6–10...
Scheme 46: Reagents and reaction conditions: i. Montmorillonite K-10 clay, microwave irradiation (560 W), 6–10...
Scheme 47: Reagents and reaction conditions: i. CeCl3·7H2O (20 mol %), NaI (20 mol %), microwave irradiation (...
Scheme 48: Reagents and reaction conditions: i. PhI(OAc)2 (3 mol %), microwave irradiation (45 °C), 6–9 min.
Scheme 49: Reagents and reaction conditions: i. 117, ethyl pyruvate, TiCl4, dichloromethane, −78 °C, 1 h; then ...
Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46
Graphical Abstract
Scheme 1: General reaction mechanism for Ag(I)-catalyzed A3-coupling reactions.
Scheme 2: A3-coupling reaction catalyzed by polystyrene-supported NHC–silver halides.
Figure 1: Various NHC–Ag(I) complexes used as catalysts for A3-coupling.
Scheme 3: Proposed reaction mechanism for NHC–AgCl catalyzed A3-coupling reactions.
Scheme 4: Liu’s synthesis of pyrrole-2-carboxaldehydes 4.
Scheme 5: Proposed reaction mechanism for Liu’s synthesis of pyrrole-2-carboxaldehydes 4.
Scheme 6: Gold-catalyzed synthesis of propargylamines 1.
Scheme 7: A3-coupling catalyzed by phosphinamidic Au(III) metallacycle 6.
Scheme 8: Gold-catalyzed KA2-coupling.
Scheme 9: A3-coupling applied to aldehyde-containing oligosaccharides 8.
Scheme 10: A3-MCR for the preparation of propargylamine-substituted indoles 9.
Scheme 11: A3-coupling interceded synthesis of furans 12.
Scheme 12: A3/KA2-coupling mediated synthesis of functionalized dihydropyrazoles 13 and polycyclic dihydropyra...
Scheme 13: Au(I)-catalyzed entry to cyclic carbamimidates 17 via an A3-coupling-type approach.
Scheme 14: Proposed reaction mechanism for the Au(I)-catalyzed synthesis of cyclic carbamimidates 17.
Figure 2: Chiral trans-1-diphenylphosphino-2-aminocyclohexane–Au(I) complex 20.
Scheme 15: A3-coupling-type synthesis of oxazoles 21 catalyzed by Au(III)–salen complex.
Scheme 16: Proposed reaction mechanism for the synthesis of oxazoles 21.
Scheme 17: Synthesis of propargyl ethyl ethers 24 by an A3-coupling-type reaction.
Scheme 18: General mechanism of Ag(I)-catalyzed MCRs of 2-alkynylbenzaldehydes, amines and nucleophiles.
Scheme 19: General synthetic pathway to 1,3-disubstituted-1,2-dihydroisoquinolines.
Scheme 20: Synthesis of 1,3-disubstituted-1,2-dihydroisoquinolines 29.
Scheme 21: Synthesis of 1,3-disubstituted-1,2-dihydroisoquinolines 35 and 36.
Scheme 22: Rh(II)/Ag(I) co-catalyzed synthesis of 1,3-disubstituted-1,2-dihydroisoquinolines 40.
Scheme 23: General synthetic pathway to 2-amino-1,2-dihydroquinolines.
Scheme 24: Synthesis of 2-amino-1,2-dihydroquinolines 47.
Scheme 25: Synthesis of tricyclic H-pyrazolo[5,1-a]isoquinoline 48.
Scheme 26: Synthesis of tricyclic H-pyrazolo[5,1-a]isoquinolines 48.
Scheme 27: Cu(II)/Ag(I) catalyzed synthesis of H-pyrazolo[5,1-a]isoquinolines 48.
Scheme 28: Synthesis of 2-aminopyrazolo[5,1-a]isoquinolines 53.
Scheme 29: Synthesis of 1-(isoquinolin-1-yl)guanidines 55.
Scheme 30: Ag(I)/Cu(I) catalyzed synthesis of 2-amino-H-pyrazolo[5,1-a]isoquinolines 58.
Scheme 31: Ag(I)/Ni(II) co-catalyzed synthesis of 3,4-dihydro-1H-pyridazino[6,1-a]isoquinoline-1,1-dicarboxyla...
Scheme 32: Ag(I) promoted activation of the α-carbon atom of the isocyanide group.
Scheme 33: Synthesis of dihydroimidazoles 65.
Scheme 34: Synthesis of oxazoles 68.
Scheme 35: Stereoselective synthesis of chiral butenolides 71.
Scheme 36: Proposed reaction mechanism for the synthesis of butenolides 71.
Scheme 37: Stereoselective three-component approach to pirrolidines 77 by means of a chiral auxiliary.
Scheme 38: Stereoselective three-component approach to pyrrolidines 81 and 82 by means of a chiral catalyst.
Scheme 39: Synthesis of substituted five-membered carbocyles 86.
Scheme 40: Synthesis of regioisomeric arylnaphthalene lactones.
Scheme 41: Enantioselective synthesis of spiroacetals 96 by Fañanás and Rodríguez [105].
Scheme 42: Enantioselective synthesis of spiroacetals 101 by Gong [106].
Scheme 43: Synthesis of polyfunctionalized fused bicyclic ketals 103 and bridged tricyclic ketals 104.
Scheme 44: Proposed reaction mechanism for the synthesis of ketals 103 and 104.
Scheme 45: Synthesis of β-alkoxyketones 108.
Scheme 46: Synthesis of N-methyl-1,4-dihydropyridines 112.
Scheme 47: Synthesis of tetrahydrocarbazoles 115–117.
Scheme 48: Plausible reaction mechanism for the synthesis of tetrahydrocarbazoles 115–117.
Scheme 49: Carboamination, carboalkoxylation and carbolactonization of terminal alkenes.
Scheme 50: Oxyarylation of alkenes with arylboronic acids and Selectfluor as reoxidant.
Scheme 51: Proposed reaction mechanism for oxyarylation of alkenes.
Scheme 52: Oxyarylation of alkenes with arylsilanes and Selectfluor as reoxidant.
Scheme 53: Oxyarylation of alkenes with arylsilanes and IBA as reoxidant.
Beilstein J. Org. Chem. 2014, 10, 237–250, doi:10.3762/bjoc.10.19
Graphical Abstract
Scheme 1: 1-Boron-substituted 1,3-diene in a tandem cycloaddition [4 + 2]/allylboration sequence.
Scheme 2: Lewis acid catalyst in the tandem cycloaddition [4 + 2]/allylboration sequence.
Scheme 3: Synthesis of an advanced precursor of clerodin.
Scheme 4: Intramolecular Diels–Alder/allylboration sequence.
Scheme 5: Diastereoselective Diels–Alder reaction with N-phenylmaleimide and 4-phenyltriazoline-3,5-dione.
Scheme 6: Asymmetric synthesis of a α-hydroxyalkylcyclohexane.
Scheme 7: Tandem [4 + 2]-cycloaddition/allylboration of 3-silyloxy- and 4-alkoxy-dienyl boronates.
Scheme 8: Metal-mediated cycloisomerization/Diels–Alder reaction/allylboration sequence.
Scheme 9: Cobalt-catalyzed Diels–Alder/allylboration sequence.
Scheme 10: A two-step reaction sequence for the synthesis of tetrahydronaphthalenes 12.
Scheme 11: Tandem sequence based on the Petasis borono–Mannich reaction as first key step.
Scheme 12: One-pot tandem dimerization/allylboration reaction of 1,3-diene-2-boronate.
Scheme 13: Tandem Diels–Alder/cross-coupling reactions of trifluoroborates 15.
Scheme 14: Diels–Alder/cross-coupling reactions of 16.
Scheme 15: Metal catalyzed tandem Diels–Alder/hydrolysis reactions.
Scheme 16: Synthesis of anti-1,5-diols 18 by triple aldehyde addition.
Scheme 17: Catalytic enantioselective three-component hetero-[4 + 2]-cycloaddition/allylboration sequence.
Scheme 18: Synthesis of natural products using the catalytic enantioselective HDA/allylboration sequence.
Scheme 19: Total synthesis of a thiomarinol derivative.
Scheme 20: Synthesis of an advanced intermediate 27 for the east fragment of palmerolide A.
Scheme 21: Bicyclic piperidines from tandem aza-[4 + 2]-cycloaddition/allylboration.
Scheme 22: Hydrogenolysis reactions of hydrazinopiperidines.
Scheme 23: Tandem aza-[4 + 2]-cycloaddition/allylboration/retrosulfinyl-ene sequence.
Scheme 24: Boronated heterodendralene 32 in [4 + 2]-cycloadditions.
Scheme 25: Synthesis of tricyclic imides derivatives.
Scheme 26: Synthesis of 37 via a HDA/allylboration/DA sequence.
Scheme 27: Diels–Alder/allylboration sequence.
Beilstein J. Org. Chem. 2013, 9, 2042–2047, doi:10.3762/bjoc.9.242
Graphical Abstract
Scheme 1: Previously reported approach from β-aminoynones for the synthesis of pyridones.
Scheme 2: Retrosynthetic analysis of (−)-epimyrtine.
Scheme 3: Synthesis of (−)-epimyrtine.
Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234
Graphical Abstract
Scheme 1: Amine radical cations’ mode of reactivity.
Scheme 2: Reductive quenching of photoexcited Ru complexes by Et3N.
Scheme 3: Photoredox aza-Henry reaction.
Scheme 4: Formation of iminium ions using BrCCl3 as stoichiometric oxidant.
Scheme 5: Oxidative functionalization of N-aryltetrahydroisoquinolines using Eosin Y.
Scheme 6: Synthetic and mechanistic studies of Eosin Y-catalyzed aza-Henry reaction.
Scheme 7: Oxidative functionalization of N-aryltetrahydroisoquinolines using RB and GO.
Scheme 8: Merging Ru-based photoredox catalysis and Lewis base catalysis for the Mannich reaction.
Scheme 9: Merging Au-based photoredox catalysis and Lewis base catalysis for the Mannich reaction.
Scheme 10: Merging Ru-based photoredox catalysis and Cu-catalyzed alkynylation reaction.
Scheme 11: Merging Ru-based photoredox catalysis and NHC catalysis.
Scheme 12: 1,3-Dipolar cycloaddition of photogenically formed azomethine ylides.
Scheme 13: Plausible mechanism for photoredox 1,3-dipolar cycloaddition.
Scheme 14: Photoredox-catalyzed cascade reaction for the synthesis of fused isoxazolidines.
Scheme 15: Plausible mechanism for the photoredox-catalyzed cascade reaction.
Scheme 16: Photoredox-catalyzed α-arylation of glycine derivatives.
Scheme 17: Photoredox-catalyzed α-arylation of amides.
Scheme 18: Intramolecular interception of iminium ions by sulfonamides.
Scheme 19: Intramolecular interception of iminium ions by alcohols and sulfonamides.
Scheme 20: Intermolecular interception of iminium ions by phosphites.
Scheme 21: Photoredox-catalyzed oxidative phosphonylation by Eosin Y.
Scheme 22: Conjugated addition of α-amino radicals to Michael acceptors.
Scheme 23: Conjugated addition of α-amino radicals to Michael acceptors assisted by a Brønsted acid.
Scheme 24: Conjugated addition of α-amino radicals derived from anilines to Michael acceptors.
Scheme 25: Oxygen switch between two pathways involving α-amino radicals.
Scheme 26: Interception of α-amino radicals by azodicarboxylates.
Scheme 27: α-Arylation of amines.
Scheme 28: Plausible mechanism for α-arylation of amines.
Scheme 29: Photoinduced C–C bond cleavage of tertiary amines.
Scheme 30: Photoredox cleavage of C–C bonds of 1,2-diamines.
Scheme 31: Proposed mechanism photoredox cleavage of C–C bonds.
Scheme 32: Intermolecular [3 + 2] annulation of cyclopropylamines with olefins.
Scheme 33: Proposed mechanism for intermolecular [3 + 2] annulation.
Scheme 34: Photoinduced clevage of N–N bonds of aromatic hydrazines and hydrazides.
Beilstein J. Org. Chem. 2013, 9, 1853–1857, doi:10.3762/bjoc.9.216
Beilstein J. Org. Chem. 2013, 9, 1737–1744, doi:10.3762/bjoc.9.200
Graphical Abstract
Scheme 1: Schematic nitro-Mannich reaction.
Scheme 2: Retrosynthetic analysis of piperazirum.
Scheme 3: (a) iBuMgCl, Et2O, −78 °C; (b) KOH, EtOH/H2O, 100 °C; (c) (COCl)2.
Scheme 4: (a) Li(Et3BH), THF, rt then 14, CF3CO2H, −78 °C, dr 70:30; (b) (CF3CO)2O, Py, CH2Cl2, 0 °C to rt; (...
Scheme 5: (a) Li(Et3BH), CH2Cl2, rt then 19, CF3CO2H, −78 °C, dr >95:5; (b) Zn, 6 M HCl, EtOAc/EtOH, rt, sing...
Scheme 6: (a) (COCl)2, DMF, CH2Cl2, rt; (b) 21, Py, DMAP, CH2Cl2, rt; (c) EDC, HOBt, THF/CH2Cl2, rt; (d) H2 (...
Figure 1: X-ray crystal structure of 2·HCl.
Beilstein J. Org. Chem. 2013, 9, 1480–1486, doi:10.3762/bjoc.9.168
Graphical Abstract
Scheme 1: Synthetic approach toward N-arylpyrroles.
Scheme 2: Isomerization of pyrrolidine 4a (PMP: 4-methoxyphenyl).
Scheme 3: Preparation of N-arylpyrroles 5a–h (unless otherwise specified, yields in brackets refer to the iso...
Scheme 4: Variation of imines.
Scheme 5: Possible mechanism.
Scheme 6: Bis(heteroaryl)methylene oxidation of 5a–f.
Beilstein J. Org. Chem. 2013, 9, 983–990, doi:10.3762/bjoc.9.113
Graphical Abstract
Scheme 1: Biogenetic origin of Vinca alkaloids.
Scheme 2: Synthetic strategy for velbanamine based on chemoselective dioxygenation.
Scheme 3: Intramolecular oxyamidation of alkene 11 with phenyliodine(III)-bis(trifluoroacetate) (PIFA) by Tel...
Scheme 4: Copper-catalyzed amination of aryliodide.
Scheme 5: Revised PIFA-promoted cyclization of amide 11.
Scheme 6: PIFA-promoted cyclization to synthesize lactone.
Figure 1: Hydrolysis of iminolactone 18 under basic conditions.
Scheme 7: “Stop-and-flow” strategy for the stepwise dioxygenation of alkenes.
Scheme 8: “Stop-and-flow” strategy for the construction of γ-lactone derivatives.
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, 486–495, doi:10.3762/bjoc.9.52
Graphical Abstract
Scheme 1: Asymmetric synthesis of 2-methyl-6-phenyl piperidine.
Scheme 2: (a) Davies amine, BuLi, THF, −78 °C; dr ≥ 94% ; (b) H2, Pd(OH)2, MeOH; (c) Na2CO3, PhCH2CO2Cl, CH2Cl...
Scheme 3: Modified synthetic route to15.
Scheme 4: Possible pathways to obtain phosphonate 13 (a) Davies amine, BuLi, THF, −78 °C; dr ≥ 95%; (b) H2, P...
Scheme 5: Synthesis of compound 14.
Scheme 6: General synthesis of compound 13 (a) Davies amine, BuLi, THF, −78 °C; (b) H2, Pd(OH)2/C, MeOH; (c) ...
Scheme 7: Optimization of conditions for the Horner–Wadsworth–Emmons reaction.
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, 1279–1283, doi:10.3762/bjoc.8.144
Graphical Abstract
Scheme 1: Working hypothesis: Decarboxylative Mannich reaction.
Beilstein J. Org. Chem. 2012, 8, 567–578, doi:10.3762/bjoc.8.64
Graphical Abstract
Figure 1: Biologically active natural products and drugs containing the piperidine ring.
Scheme 1: A general strategy to 5-nitropiperidin-2-ones and related heterocycles.
Scheme 2: The synthesis of Michael adduct model substrates for the nitro-Mannich/lactamisation cascade.
Scheme 3: Nitro-Mannich/lactamisation cascade with in situ formed imines.
Figure 2: Cyclic imines employed in nitro-Mannich/lactamisation cascade.
Scheme 4: Nitro-Mannich/lactamisation cascade of diastereomeric Michael adducts 6a, 6a’’ with cyclic imine 5a....
Scheme 5: Nitro-Mannich/lactamisation cascade with cyclic imines. aDiastereomeric ratio in a crude reaction m...
Scheme 6: Possible explanations for the observed high stereoselectivities in the nitro-Mannich/lactamisation ...
Scheme 7: Thermodynamically-driven epimerisation of 5-nitropiperidin-2-ones 2m and 2m’.
Figure 3: Thermodynamically driven epimerisation of 5-nitropiperidin-2-ones 2m and 2m’; identical diastereome...
Scheme 8: One-pot three/four-component enantioselective Michael addition/nitro-Mannich/lactamisation cascade.
Scheme 9: Protodenitration of 5-nitropiperidin-2-ones.
Scheme 10: Various reductions of denitrated heterocycles.
Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57
Graphical Abstract
Figure 1: Structures of atorvastatin and other commercial statins.
Figure 2: Structure of compactin.
Scheme 1: Synthesis of pentasubstituted pyrroles.
Scheme 2: [3 + 2] Cycloaddition to prepare 5-isopropylpyrroles.
Scheme 3: Regiospecific [3 + 2] cycloaddition to prepare the pyrrole scaffold.
Scheme 4: Formation of the pyrrole core of atorvastatin via [3 + 2] cycloaddition.
Scheme 5: Formation of pyrrole 33 via the Paal–Knorr reaction.
Scheme 6: Convergent synthesis towards atorvastatin.
Figure 3: Binding pocket of sunitinib in the TRK KIT.
Scheme 7: Synthesis of sunitinib.
Scheme 8: Alternative synthesis of sunitinib.
Scheme 9: Key steps in the syntheses of sumatriptan and zolmitriptan.
Scheme 10: Introduction of the N,N-dimethylaminoethyl side chain.
Scheme 11: Japp–Klingemann reaction in the synthesis of sumatriptan.
Scheme 12: Synthesis of the intermediate sulfonyl chlorides 62 and 63.
Scheme 13: Alternative introduction of the sulfonamide.
Scheme 14: Negishi-type coupling to benzylic sulfonamides.
Scheme 15: Heck reaction used to introduce the sulfonamide side chain of naratriptan.
Scheme 16: Synthesis of the oxazolinone appendage of zolmitriptan.
Scheme 17: Grandberg indole synthesis used in the preparation of rizatriptan.
Scheme 18: Improved synthesis of rizatriptan.
Scheme 19: Larock-type synthesis of rizatriptan.
Scheme 20: Synthesis of eletriptan.
Scheme 21: Heck coupling for the indole system in eletriptan.
Scheme 22: Attempted Fischer indole synthesis of elatriptan.
Scheme 23: Successful Fischer indole synthesis for eletriptan.
Scheme 24: Mechanistic rationale for the Bischler–Möhlau reaction.
Scheme 25: Bischler-type indole synthesis used in the fluvastatin sodium synthesis.
Scheme 26: Palladium-mediated synthesis of ondansetron.
Scheme 27: Fischer indole synthesis of ondansetron.
Scheme 28: Optimised Pictet–Spengler reaction towards tadalafil.
Figure 4: Structures of carvedilol 136 and propranolol 137.
Scheme 29: Synthesis of the carbazole core of carvedilol.
Scheme 30: Alternative syntheses of 4-hydroxy-9H-carbazole.
Scheme 31: Convergent synthesis of etodolac.
Scheme 32: Alternative synthesis of etodolac.
Figure 5: Structures of imidazole-containing drugs.
Scheme 33: Synthesis of functionalised imidazoles towards losartan.
Scheme 34: Direct synthesis of the chlorinated imidazole in losartan.
Scheme 35: Synthesis of trisubstituted imidazoles.
Scheme 36: Preparation of the imidazole ring in olmesartan.
Scheme 37: Synthesis of ondansetron.
Scheme 38: Alternative route to ondansetron and its analogues.
Scheme 39: Proton pump inhibitors and synthesis of esomeprazole.
Scheme 40: Synthesis of benzimidazole core pantoprazole.
Figure 6: Structure of rabeprazole 194.
Scheme 41: Synthesis of candesartan.
Scheme 42: Alternative access to the candesartan key intermediate 216.
Scheme 43: .Medicinal chemistry route to telmisartan.
Scheme 44: Improved synthesis of telmisartan.
Scheme 45: Synthesis of zolpidem.
Scheme 46: Copper-catalysed 3-component coupling towards zolpidem.
Figure 7: Structure of celecoxib.
Scheme 47: Preparation of celecoxib.
Scheme 48: Alternative synthesis of celecoxib.
Scheme 49: Regioselective access to celecoxib.
Scheme 50: Synthesis of pazopanib.
Scheme 51: Syntheses of anastrozole, rizatriptan and letrozole.
Scheme 52: Regioselective synthesis of anastrozole.
Scheme 53: Triazine-mediated triazole formation towards anastrozole.
Scheme 54: Alternative routes to 1,2,4-triazoles.
Scheme 55: Initial synthetic route to sitagliptin.
Figure 8: Binding of sitagliptin within DPP-IV.
Scheme 56: The process route to sitagliptin key intermediate 280.
Scheme 57: Synthesis of maraviroc.
Scheme 58: Synthesis of alprazolam.
Scheme 59: The use of N-nitrosoamidine derivatives in the preparation of fused benzodiazepines.
Figure 9: Structures of itraconazole, ravuconazole and voriconazole.
Scheme 60: Synthesis of itraconazole.
Scheme 61: Synthesis of rufinamide.
Scheme 62: Representative tetrazole formation in valsartan.
Figure 10: Structure of tetrazole containing olmesartan, candesartan and irbesartan.
Scheme 63: Early stage introduction of the tetrazole in losartan.
Scheme 64: Synthesis of cilostazol.
Figure 11: Structure of cefdinir.
Scheme 65: Semi-synthesis of cefdinir.
Scheme 66: Thiazole syntheses towards ritonavir.
Scheme 67: Synthesis towards pramipexole.
Scheme 68: Alternative route to pramipexole.
Scheme 69: Synthesis of famotidine.
Scheme 70: Efficient synthesis of the hyperuricemic febuxostat.
Scheme 71: Synthesis of ziprasidone.
Figure 12: Structure of mometasone.
Scheme 72: Industrial access to 2-furoic acid present in mometasone.
Scheme 73: Synthesis of ranitidine from furfuryl alcohol.
Scheme 74: Synthesis of nitrofurantoin.
Scheme 75: Synthesis of benzofuran.
Scheme 76: Synthesis of amiodarone.
Scheme 77: Synthesis of raloxifene.
Scheme 78: Alternative access to the benzo[b]thiophene core of raloxifene.
Scheme 79: Gewald reaction in the synthesis of olanzapine.
Scheme 80: Alternative synthesis of olanzapine.
Figure 13: Access to simple thiophene-containing drugs.
Scheme 81: Synthesis of clopidogrel.
Scheme 82: Pictet–Spengler reaction in the preparation of tetrahydrothieno[3,2-c]pyridine (422).
Scheme 83: Alternative synthesis of key intermediate 422.
Figure 14: Co-crystal structures of timolol (left) and carazolol (right) in the β-adrenergic receptor.
Scheme 84: Synthesis of timolol.
Scheme 85: Synthesis of tizanidine 440.
Scheme 86: Synthesis of leflunomide.
Scheme 87: Synthesis of sulfamethoxazole.
Scheme 88: Synthesis of risperidone.
Figure 15: Relative abundance of selected transformations.
Figure 16: The abundance of heterocycles within top 200 drugs (5-membered rings).
Beilstein J. Org. Chem. 2010, 6, 1206–1210, doi:10.3762/bjoc.6.138
Graphical Abstract
Scheme 1: Retrosynthetic analysis outlining the stereocontrolled construction of the aminopolyol core of (−)-...
Scheme 2: Depictions of the likely major conformations of the siloxane (A) and disiloxane (B) rings.
Scheme 3: Confirmation of the relative stereochemistry of bis(triazoline) 14a. (a) TfOH, CH3CN, rt, 18 h; (b)...
Beilstein J. Org. Chem. 2010, 6, 876–879, doi:10.3762/bjoc.6.103
Graphical Abstract
Figure 1: Spiro[pyrrolidin-3,3'-oxindoles].
Scheme 1: Reagents and conditions: a) CH2=CHCH2OCH2P+ Ph3Cl−, t-BuO− Na+, THF, 0 °C; b) xylene, reflux; c) Jo...
Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19
Graphical Abstract
Scheme 1: Enantioselective addition of trimethylsilyl cyanide to benzaldehyde.
Scheme 2: Asymmetric catalytic hydrogenation in a falling-film microreactor.
Scheme 3: Aldol reaction catalyzed by 5-(pyrrolidine-2-yl)tetrazole.
Scheme 4: Enantioselective addition of diethylzinc to aryl aldehydes.
Scheme 5: Glyoxylate-ene reaction in flow.
Scheme 6: Asymmetric synthesis of ß-lactams.
Scheme 7: α-Chlorination of acid chlorides in flow.
Scheme 8: Asymmetric Michael reaction in continuous flow.
Scheme 9: Enantioselective addition of Et2Zn to benzaldehyde using monolithic chiral amino alcohol.
Scheme 10: Continuous-flow hydrolytic dynamic kinetic resolution of epibromohydrin (32).
Scheme 11: Continuous-flow asymmetric cyclopropanation.
Scheme 12: Continuous asymmetric hydrogenation of dimethyl itaconate in scCO2.
Scheme 13: Continuous asymmetric transfer hydrogenation of acetophenone.
Scheme 14: Asymmetric epoxidation using a continuous flow membrane reactor.
Scheme 15: Enzymatic cyanohydrin formation in a microreactor.
Scheme 16: Resolution of (R/S)- 54 with immobilized lipase in a continuous scCO2- flow reactor.
Scheme 17: Enantioselective separation of Acetyl-D-Phe in a continuous flow reactor.