Search for "directed lithiation" in Full Text gives 9 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105
Graphical Abstract
Scheme 1: Reported synthetic methods for the selenation of aromatic compounds.
Scheme 2: Reaction of selenium dioxide with aniline.
Scheme 3: Reaction of selenium dioxide with o-anisidine.
Scheme 4: Reaction of methyl anthranilate with SeO2.
Scheme 5: Reaction mechanism for the formation of diaryl monoselenides.
Scheme 6: Reaction mechanism for the formation of oxamides.
Scheme 7: Reaction mechanism for the formation of quinone 10.
Figure 1: Molecular structure of 3. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å): O...
Figure 2: Molecular structure of 9. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å): O...
Figure 3: Molecular structure of 13. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å): ...
Figure 4: Molecular structure of 10. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å) a...
Figure 5: Molecular structure of 11. Thermal ellipsoids drawn at 50% probability. Selected bond angles (°): C...
Figure 6: Molecular structure of 12. Thermal ellipsoids drawn at 50% probability. Selected bond angles (°): C...
Figure 7: Relative energy levels of arylamines and SeO2.
Figure 8: Computationally optimized structure of aniline (a), o-anisidine (b), and methyl anthranilate (c), w...
Scheme 8: Resonance structures for the delocalization of the nitrogen lone pair into the π-system.
Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141
Graphical Abstract
Figure 1: The correlation between stability and Clar's rule in acenes.
Scheme 1: General synthetic strategies to access the biphenylene core 1.
Figure 2: [N]Phenylenes 7–12 with different topologies.
Scheme 2: Synthesis of POAs 15a and 15b via reactions of BBD 13 and bis(cyanomethyl) compounds 14a and 14b.
Scheme 3: Synthesis of benzo[b]biphenylene (18).
Scheme 4: Synthesis of benzobiphenylene 18 and POA 21.
Scheme 5: Synthesis of symmetric POAs 25a and 25b.
Scheme 6: Synthesis of POA 29 via palladium-catalyzed annulation/aromatization reaction.
Scheme 7: Synthesis of bisphenylene-containing structures 34a–c.
Scheme 8: Synthesis of curved PAH 38 via Pd-catalyzed annulation and Ir-catalyzed cycloaddition reactions.
Scheme 9: Synthesis of [3]naphthylenes.
Scheme 10: Sequential Pd-catalyzed annulation reactions.
Scheme 11: Synthesis of biphenylene-containing unsymmetrical azaacenes 54a–c.
Scheme 12: Synthesis of biphenylene containing symmetrical azaacenes 58a,b.
Scheme 13: Synthesis of azaacene analogues 62–64.
Scheme 14: Synthesis of POA-type structure 69.
Scheme 15: Synthesis of boron-doped POA 73.
Scheme 16: Synthesis of “v”- and “z”-shaped B-POAs 77 and 78.
Scheme 17: Synthesis of boron-doped extended POA 84.
Scheme 18: Ag(111) surface-catalyzed synthesis of POA 87.
Scheme 19: Au(100) and Au(111) surface-catalyzed synthesis of POA 91.
Scheme 20: Au(111) on-surface synthesis of POA 87.
Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90
Graphical Abstract
Figure 1: Biologically active 1,2-azaphospholine 2-oxide derivatives.
Figure 2: Diverse synthetic strategies for the preparation of 1,2-azaphospholidine and 1,2-azaphospholine 2-o...
Scheme 1: Synthesis of 1-phenyl-2-phenylamino-γ-phosphonolactam (2) from N,N’-diphenyl 3-chloropropylphosphon...
Scheme 2: Synthesis of 2-ethoxy-1-methyl-γ-phosphonolactam (6) from ethyl N-methyl-(3-bromopropyl)phosphonami...
Scheme 3: Synthesis of 2-aryl-1-methyl-2,3-dihydrobenzo[c][1,2]azaphosphole 1-oxides 13 from N-aryl-2-chlorom...
Scheme 4: Synthesis of 2,3-dihydrobenzo[c][1,2]azaphosphole 1-oxides from alkylarylphosphinyl or diarylphosph...
Scheme 5: Synthesis of 3-arylmethylidene-2,3-dihydrobenzo[c][1,2]azaphosphole 1-oxides via the TBAF-mediated ...
Scheme 6: Synthesis of 2-hydrobenzo[c][1,2]azaphosphol-3-one 1-oxides via the metal-free intramolecular oxida...
Scheme 7: Synthesis of 1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides 42 and 44 from ethyl/benzyl 2-bromobenzy...
Scheme 8: Synthesis of azaphospholidine 2-oxides/sulfide from 1,2-oxaphospholane 2-oxides/sulfides and 1,2-th...
Scheme 9: Synthesis of 1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides/sulfides from 2-aminobenzyl(phenyl)phosp...
Scheme 10: Synthesis of 1,3-dihydrobenzo[d][1,2]azaphosphole 2-sulfide (59) from zwitterionic 2-aminobenzyl(ph...
Scheme 11: Synthesis of 1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides from 2-aminobenzyl(methyl/phenyl)phosphi...
Scheme 12: Synthesis of ethyl 2-methyl-1,2-azaphospholidine-5-carboxylate 2-oxide 69 from 2-amino-4-(hydroxy(m...
Scheme 13: Synthesis of 2-methoxy-1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxide 71 from dimethyl 2-(methylamino...
Scheme 14: Synthesis of tricyclic γ-phosphonolactams via formation of the P–C bond.
Scheme 15: Synthesis of γ-phosphonolactams 85 from ethyl 2-(3-chloropropyl)aminoalkanoates with diethyl chloro...
Scheme 16: Synthesis of N-phosphoryl- and N-thiophosphoryl-1,2-azaphospholidine 2-oxides 90/2-sulfides 91 from...
Scheme 17: Synthesis of 1-methyl-1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides 56a and 93 from P-(chloromethyl...
Scheme 18: Synthesis of 2-allylamino-1,5-dihydro-1,2-azaphosphole 2-oxides from N,N’-diallyl-vinylphosphonodia...
Scheme 19: Diastereoselective synthesis of 2-allylamino-1,5-dihydro-1,2-azaphosphole 2-oxides from N,N’-dially...
Scheme 20: Synthesis of 1-alkyl-3-benzoyl-2-ethoxy-1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides 106 from ethy...
Scheme 21: Synthesis of cyclohexadiene-fused γ-phosphinolactams from diphenyl-N-benzyl-N-methylphosphinamide (...
Scheme 22: Synthesis of cyclohexadiene-fused γ-phosphinolactams from diphenyl-N-alkyl-N-benzylphosphinamides.
Scheme 23: Synthesis of cyclohexadiene-fused γ-phosphinolactams from diphenyl-N-methyl-N-(1-phenylethyl)phosph...
Scheme 24: Synthesis of benzocyclohexadiene-fused γ-phosphinolactams from dinaphth-1-yl-N-alkyl-N-benzylphosph...
Scheme 25: Synthesis of benzocyclohexadiene-fused γ-phosphinolactams from dinaphth-1-yl-N-benzyl-N-methylphosp...
Scheme 26: Synthesis of carbonyl-containing benzocyclohexadiene-fused γ-phosphinolactams from dinaphth-1-yl-N-...
Scheme 27: Synthesis of benzocyclohexadiene-fused γ-phosphinolactams from dinaphthyl-N-benzyl-N-methylphosphin...
Scheme 28: Synthesis of cyclohexadiene-fused 1-(N-benzyl-N-methyl)amino-γ-phosphinolactams from aryl-N,N’-dibe...
Scheme 29: Synthesis of bis(cyclohexadiene-fused γ-phosphinolactam)s from bis(diphenyl-N-benzylphosphinamide)s....
Scheme 30: Synthesis of bis(hydroxymethyl-derived cyclohexadiene-fused γ-phosphinolactam)s from tetramethylene...
Scheme 31: Synthesis of 2-aryl/dimethylamino-1-ethoxy-2-hydrobenzo[c][1,2]azaphosphol-3-one 1-oxides from ethy...
Scheme 32: Synthesis of ethyl 2-ethoxy-1,2-azaphospholidine-4-carboxylate 2-oxides from ethyl 2-((chloro(ethox...
Scheme 33: Synthesis of (1S,3R)-2-(tert-butyldiphenylsilyl)-3-methyl-1-phenyl-2,3-dihydrobenzo[c][1,2]azaphosp...
Scheme 34: Synthesis of 2,3,3a,9a-tetrahydro-4H-1,2-azaphospholo[5,4-b]chromen-4-one (215) from 3-(phenylamino...
Scheme 35: Synthesis of quinoline-fused 1,2-azaphospholine 2-oxides from 2-azidoquinoline-3-carbaldehydes and ...
Scheme 36: Synthesis of 1-hydro-1,2-azaphosphol-5-one 2-oxide from cyanoacetohydrazide with phosphonic acid an...
Scheme 37: Synthesis of chromene-fused 5-oxo-1,2-azaphospolidine 2-oxides.
Scheme 38: Synthesis of (R)-1-phenyl-2-((R)-1-phenylethyl)-2-hydrobenzo[c][1,2]azaphosphol-3-one 1-oxide (239)...
Scheme 39: Synthesis of dihydro[1,2]azaphosphole 1-oxides from aryl/vinyl-N-phenylphosphonamidates and aryl-N-...
Scheme 40: Synthesis of 1,3-dihydro-[1,2]azaphospholo[5,4-b]pyridine 2-oxides.
Beilstein J. Org. Chem. 2020, 16, 2136–2140, doi:10.3762/bjoc.16.181
Graphical Abstract
Figure 1: Structures of pentacene and fluorinated pentacenes.
Scheme 1: Retrosynthetic analysis of F2PEN 5.
Scheme 2: Synthesis of F2PEN 5.
Scheme 3: Decomposition of diol 13 in solution.
Figure 2: UV–vis spectrum of F2PEN 5 in CH2Cl2.
Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117
Graphical Abstract
Figure 1: Inherently chiral calix[4]arene-based phase-transfer catalysts.
Scheme 1: Asymmetric alkylations of 3 catalyzed by (±)-1 and (±)-2 under phase-transfer conditions.
Scheme 2: Synthesis of chiral calix[4]arene-based phase-transfer catalyst 7 and structure of O’Donnell’s N-be...
Scheme 3: Asymmetric alkylation of glycine derivative 3 catalyzed by calixarene-based phase-transfer catalyst ...
Figure 2: Calix[4]arene-amides used as phase-transfer catalysts.
Scheme 4: Phase-transfer alkylation of 3 catalyzed by calixarene-triamide 12.
Scheme 5: Synthesis of inherently chiral calix[4]arenes 20a/20b substituted at the lower rim. Reaction condit...
Scheme 6: Asymmetric Henry reaction between 21 and 22 catalyzed by 20a/20b.
Figure 3: Proposed transition state model of asymmetric Henry reaction.
Scheme 7: Synthesis of enantiomerically pure phosphinoferrocenyl-substituted calixarene ligands 27–29.
Scheme 8: Asymmetric coupling reaction of aryl boronates and aryl halides in the presence of calixarene mono ...
Scheme 9: Asymmetric allylic alkylation in the presence of calix[4]arene ligand (S,S)-29.
Figure 4: Structure of inherently chiral oxazoline calix[4]arenes applied in the palladium-catalyzed Tsuji–Tr...
Scheme 10: Asymmetric Tsuji–Trost reaction in the presence of calix[4]arene ligands 36–39.
Figure 5: BINOL-derived calix[4]arene-diphosphite ligands.
Scheme 11: Asymmetric hydrogenation of 41a and 41b catalyzed by in situ-generated catalysts comprised of [Rh(C...
Figure 6: Inherently chiral calix[4]arene 43 containing a diarylmethanol structure.
Scheme 12: Asymmetric Michael addition reaction of 44 with 45 catalyzed by 43.
Figure 7: Calix[4]arene-based chiral primary amine–thiourea catalysts.
Scheme 13: Asymmetric Michael addition of 48 with 49 catalyzed by 47a and 47b.
Scheme 14: Enantioselective Michael addition of 51 to 52 catalyzed by calix[4]arene thioureas.
Scheme 15: Synthesis of calix[4]arene-based tertiary amine–thioureas 54–56.
Scheme 16: Asymmetric Michael addition of 34 and 57 to nitroalkenes 49 catalyzed by 54b.
Scheme 17: Synthesis of p-tert-butylcalix[4]arene bis-squaramide derivative 64.
Scheme 18: Asymmetric Michael addition catalyzed by 64.
Scheme 19: Synthesis of chiral p-tert-butylphenol analogue 68.
Figure 8: Novel prolinamide organocatalysts based on the calix[4]arene scaffold.
Scheme 20: Asymmetric aldol reactions of 72 with 70 and 71 catalyzed by 69b.
Scheme 21: Synthesis of p-tert-butylcalix[4]arene-based chiral organocatalysts 75 and 78 derived from L-prolin...
Scheme 22: Synthesis of upper rim-functionalized calix[4]arene-based L-proline derivative 83.
Scheme 23: Synthesis and proposed structure of Calix-Pro-MN (86).
Figure 9: Calix[4]arene-based L-proline catalysts containing ester, amide and acid units.
Scheme 24: Synthesis of calix[4]arene-based prolinamide 92.
Scheme 25: Calixarene-based catalysts for the aldol reaction of 21 with 70.
Scheme 26: Asymmetric aldol reactions of 72 with cyclic ketones catalyzed by calix[4]arene-based chiral organo...
Figure 10: A proposed structure for catalyst 92 in H2O.
Scheme 27: Synthetic route for organocatalyst 98.
Scheme 28: Asymmetric aldol reactions catalyzed by 99.
Figure 11: Proposed catalytic environment for catalyst 99 in the presence of water.
Scheme 29: Asymmetric aldol reactions between 94 and 72 catalyzed by 55a.
Scheme 30: Enantioselective Biginelli reactions catalyzed by 69f.
Scheme 31: Synthesis of calix[4]arene–(salen) complexes.
Scheme 32: Enantioselective epoxidation of 108 catalyzed by 107a/107b.
Scheme 33: Synthesis of inherently chiral calix[4]arene catalysts 111 and 112.
Scheme 34: Enantioselective MPV reduction.
Scheme 35: Synthesis of chiral calix[4]arene ligands 116a–c.
Scheme 36: Asymmetric MPV reduction with chiral calix[4]arene ligands.
Scheme 37: Chiral AlIII–calixarene complexes bearing distally positioned chiral substituents.
Scheme 38: Asymmetric MPV reduction in the presence of chiral calix[4]arene diphosphites.
Scheme 39: Synthesis of enantiomerically pure inherently chiral calix[4]arene phosphonic acid.
Scheme 40: Asymmetric aza-Diels–Alder reactions catalyzed by (cR,pR)-121.
Scheme 41: Asymmetric ring opening of epoxides catalyzed by (cR,pR)-121.
Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51
Graphical Abstract
Figure 1: Microreactor technologies and flow chemistry for a sustainable chemistry.
Scheme 1: A flow microreactor system for the generation and trapping of highly unstable carbamoyllithium spec...
Scheme 2: Flow synthesis of functionalized α-ketoamides.
Scheme 3: Reactions of benzyllithiums.
Scheme 4: Trapping of benzyllithiums bearing carbonyl groups enabled by a flow microreactor. (Adapted with pe...
Scheme 5: External trapping of chloromethyllithium in a flow microreactor system.
Scheme 6: Scope for the direct tert-butoxycarbonylation using a flow microreactor system.
Scheme 7: Control of anionic Fries rearrangement reactions by using submillisecond residence time. (Adapted w...
Figure 2: Chip microreactor (CMR) fabricated with six layers of polyimide films. (Reproduced with permission ...
Scheme 8: Flow microreactor system for lithiation, borylation, Suzuki–Miyaura coupling and selected examples ...
Scheme 9: Experimental setup for the flow synthesis of 2-fluorobi(hetero)aryls by directed lithiation, zincat...
Scheme 10: Experimental setup for the coupling of fluoro-substituted pyridines. (Adapted with permission from [53]...
Scheme 11: Continuous flow process setup for the preparation of 11 (Reproduced with permission from [54], copyrigh...
Scheme 12: Continuous-flow photocatalytic oxidation of thiols to disulfides.
Scheme 13: Trifluoromethylation by continuous-flow photoredox catalysis.
Scheme 14: Flow photochemical synthesis of 6(5H)-phenanthridiones from 2-chlorobenzamides.
Scheme 15: Synthesis of biaryls 14a–g under photochemical flow conditions.
Scheme 16: Flow oxidation of hydrazones to diazo compounds.
Scheme 17: Synthetic use of flow-generated diazo compounds.
Scheme 18: Ley’s flow approach for the generation of diazo compounds.
Scheme 19: Iterative strategy for the sequential coupling of diazo compounds.
Scheme 20: Integrated synthesis of Bakuchiol precursor via flow-generated diazo compounds.
Scheme 21: Kappe’s continuous-flow reduction of olefines with diimide.
Scheme 22: Multi-injection setup for the reduction of artemisinic acid.
Scheme 23: Flow reactor system for multistep synthesis of (S)-rolipram. Pumps are labelled a, b, c, d and e; L...
Figure 3: Reconfigurable modules and flowcharts for API synthesis. (Reproduced with permission from [85], copyrig...
Figure 4: Reconfigurable system for continuous production and formulation of APIs. (Reproduced with permissio...
Beilstein J. Org. Chem. 2014, 10, 2751–2755, doi:10.3762/bjoc.10.291
Graphical Abstract
Scheme 1: Synthesis of inherently chiral calix[4]arenes.
Scheme 2: Synthesis of tert-butyloxazoline calix[4]arenes.
Figure 1: N,S Ligands.
Scheme 3: Tsuji–Trost reaction.
Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265
Graphical Abstract
Scheme 1: Scaled industrial processes for the synthesis of simple pyridines.
Scheme 2: Synthesis of nicotinic acid from 2-methyl-5-ethylpyridine (1.11).
Scheme 3: Synthesis of 3-picoline and nicotinic acid.
Scheme 4: Synthesis of 3-picoline from 2-methylglutarodinitrile 1.19.
Scheme 5: Picoline-based synthesis of clarinex (no yields reported).
Scheme 6: Mode of action of proton-pump inhibitors and structures of the API’s.
Scheme 7: Hantzsch-like route towards the pyridine rings in common proton pump inhibitors.
Figure 1: Structures of rosiglitazone (1.40) and pioglitazone (1.41).
Scheme 8: Synthesis of rosiglitazone.
Scheme 9: Syntheses of 2-pyridones.
Scheme 10: Synthesis and mechanism of 2-pyrone from malic acid.
Scheme 11: Polymer-assisted synthesis of rosiglitazone.
Scheme 12: Synthesis of pioglitazone.
Scheme 13: Meerwein arylation reaction towards pioglitazone.
Scheme 14: Route towards pioglitazone utilising tyrosine.
Scheme 15: Route towards pioglitazone via Darzens ester formation.
Scheme 16: Syntheses of the thiazolidinedione moiety.
Scheme 17: Synthesis of etoricoxib utilising Negishi and Stille cross-coupling reactions.
Scheme 18: Synthesis of etoricoxib via vinamidinium condensation.
Figure 2: Structures of nalidixic acid, levofloxacin and moxifloxacin.
Scheme 19: Synthesis of moxifloxacin.
Scheme 20: Synthesis of (S,S)-2,8-diazabicyclo[4.3.0]nonane 1.105.
Scheme 21: Synthesis of levofloxacin.
Scheme 22: Alternative approach to the levofloxacin core 1.125.
Figure 3: Structures of nifedipine, amlodipine and clevidipine.
Scheme 23: Mg3N2-mediated synthesis of nifedipine.
Scheme 24: Synthesis of rac-amlodipine as besylate salt.
Scheme 25: Aza Diels–Alder approach towards amlodipine.
Scheme 26: Routes towards clevidipine.
Figure 4: Examples of piperidine containing drugs.
Figure 5: Discovery of tiagabine based on early leads.
Scheme 27: Synthetic sequences to tiagabine.
Figure 6: Structures of solifenacin (2.57) and muscarine (2.58).
Scheme 28: Enantioselective synthesis of solifenacin.
Figure 7: Structures of DPP-4 inhibitors of the gliptin-type.
Scheme 29: Formation of inactive diketopiperazines from cis-rotameric precursors.
Figure 8: Co-crystal structure of carmegliptin bound in the human DPP-4 active site (PDB 3kwf).
Scheme 30: Improved route to carmegliptin.
Figure 9: Structures of lamivudine and zidovudine.
Scheme 31: Typical routes accessing uracil, thymine and cytosine.
Scheme 32: Coupling between pyrimidones and riboses via the Vorbrüggen nucleosidation.
Scheme 33: Synthesis of lamivudine.
Scheme 34: Synthesis of raltegravir.
Scheme 35: Mechanistic studies on the formation of 3.22.
Figure 10: Structures of selected pyrimidine containing drugs.
Scheme 36: General preparation of pyrimidines and dihydropyrimidones.
Scheme 37: Synthesis of imatinib.
Scheme 38: Flow synthesis of imatinib.
Scheme 39: Syntheses of erlotinib.
Scheme 40: Synthesis of erlotinib proceeding via Dimroth rearrangement.
Scheme 41: Synthesis of lapatinib.
Scheme 42: Synthesis of rosuvastatin.
Scheme 43: Alternative preparation of the key aldehyde towards rosuvastatin.
Figure 11: Structure comparison between nicotinic acetylcholine receptor agonists.
Scheme 44: Syntheses of varenicline and its key building block 4.5.
Scheme 45: Synthetic access to eszopiclone and brimonidine via quinoxaline intermediates.
Figure 12: Bortezomib bound in an active site of the yeast 20S proteasome ([114], pdb 2F16).
Scheme 46: Asymmetric synthesis of bortezomib.
Figure 13: Structures of some prominent piperazine containing drugs.
Figure 14: Structural comparison between the core of aplaviroc (4.35) and a type-1 β-turn (4.36).
Scheme 47: Examplary synthesis of an aplaviroc analogue via the Ugi-MCR.
Scheme 48: Syntheses of azelastine (5.1).
Figure 15: Structures of captopril, enalapril and cilazapril.
Scheme 49: Synthesis of cilazapril.
Figure 16: Structures of lamotrigine, ceftriaxone and azapropazone.
Scheme 50: Synthesis of lamotrigine.
Scheme 51: Alternative synthesis of lamotrigine (no yields reported).
Figure 17: Structural comparison between imiquimod and the related adenosine nucleoside.
Scheme 52: Conventional synthesis of imiquimod (no yields reported).
Scheme 53: Synthesis of imiquimod.
Scheme 54: Synthesis of imiquimod via tetrazole formation (not all yields reported).
Figure 18: Structures of various anti HIV-medications.
Scheme 55: Synthesis of abacavir.
Figure 19: Structures of diazepam compared to modern replacements.
Scheme 56: Synthesis of ocinaplon.
Scheme 57: Access to zaleplon and indiplon.
Scheme 58: Different routes towards the required N-methylpyrazole 6.65 of sildenafil.
Scheme 59: Polymer-supported reagents in the synthesis of key aminopyrazole 6.72.
Scheme 60: Early synthetic route to sildenafil.
Scheme 61: Convergent preparations of sildenafil.
Figure 20: Comparison of the structures of sildenafil, tadalafil and vardenafil.
Scheme 62: Short route to imidazotriazinones.
Scheme 63: Alternative route towards vardenafils core imidazotriazinone (6.95).
Scheme 64: Bayer’s approach to the vardenafil core.
Scheme 65: Large scale synthesis of vardenafil.
Scheme 66: Mode of action of temozolomide (6.105) as methylating agent.
Scheme 67: Different routes to temozolomide.
Scheme 68: Safer route towards temozolomide.
Figure 21: Some unreported heterocyclic scaffolds in top market drugs.
Beilstein J. Org. Chem. 2011, 7, 1219–1227, doi:10.3762/bjoc.7.142
Graphical Abstract
Scheme 1: Lithiation and substitution of isoindolin-1-ones [43].
Scheme 2: Lithiation and cyclization of N-tert-butyl-N-benzylbenzamides [45].
Scheme 3: Lithiation and substitution of 1 at −20 °C [69].
Figure 1: Structures of 4–6.
Scheme 4: A possible mechanism for the formation of 6.
Figure 2: X-Ray crystal structures of crystallized compounds 12 and 15–18.
Figure 3: Structures of compounds 41–44.
Figure 4: X-ray crystal structures of compounds 38 and 39.