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Search for "N-tosylimine" in Full Text gives 3 result(s) in Beilstein Journal of Organic Chemistry.
Substituent-controlled construction of A4B2-hexaphyrins and A3B-porphyrins: a mechanistic evaluation
- Seda Cinar,
- Dilek Isik Tasgin and
- Canan Unaleroglu
Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135
- of porphyrinogen and hexaphyrinogen forms. Keywords: A4B2-hexaphyrin; A3B-porphyrin; N-tosylimine; Cu(OTf)2 catalysis; HRESI–TOF analysis; Introduction Porphyrins and expanded porphyrins have found widespread applications in supramolecular chemistry [1][2][3][4]. Expanded porphyrins are utilized as
- -substituted N-tosylimine and 5,10-bis(pentafluorophenyl)tripyrromethane formed A6-hexaphyrin as the main product along with the inevitable formation of side products, A4-porphyrin and higher expanded porphyrins [28]. meso-Phenyloligopyrroles having electron-rich substituents at the 2-, 4-, or 6-positions were
- )2 (Table 1). Initially, the unsubstituted phenyl-bearing N-tosylimine 2a was reacted with tripyrrane 1 in CH2Cl2 under previously reported conditions [28], however, the desired hexaphyrin could not been isolated. Under these conditions, only product 3a, which is defined as A3B-type porphyrin was
Graphical Abstract
Scheme 1: Retrosynthetic method for A4B2-hexaphyrin and A3B-porphyrin synthesis.
Figure 1: Mass spectrum of the reaction mixture of 1 and 2d at 30 min at 0 °C with assigned intermediates (po...
Scheme 2: A suggested reaction pathway for the formation of A4B2-hexaphyrins and A3B-porphyrins.
Figure 2: Intermediates in the reaction mixture of 5 and 2h at 30 min at 0 °C.
Chiral phosphines in nucleophilic organocatalysis
- Yumei Xiao,
- Zhanhu Sun,
- Hongchao Guo and
- Ohyun Kwon
Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218
Graphical Abstract
Figure 1: Cyclic chiral phosphines based on bridged-ring skeletons.
Figure 2: Cyclic chiral phosphines based on binaphthyl skeletons.
Figure 3: Cyclic chiral phosphines based on ferrocene skeletons.
Figure 4: Cyclic chiral phosphines based on spirocyclic skeletons.
Figure 5: Cyclic chiral phosphines based on phospholane ring skeletons.
Figure 6: Acyclic chiral phosphines.
Figure 7: Multifunctional chiral phosphines based on binaphthyl skeletons.
Figure 8: Multifunctional chiral phosphines based on amino acid skeletons.
Scheme 1: Asymmetric [3 + 2] annulations of allenoates with electron-deficient olefins, catalyzed by the chir...
Scheme 2: Asymmetric [3 + 2] annulations of allenoate and enones, catalyzed by the chiral binaphthyl-based ph...
Scheme 3: Asymmetric [3 + 2] annulations of N-substituted olefins and allenoates, catalyzed by the chiral bin...
Scheme 4: Asymmetric [3 + 2] annulations of 2-aryl-1,1-dicyanoethylenes with ethyl allenoate, catalyzed by th...
Scheme 5: Asymmetric [3 + 2] annulations of 3-alkylideneindolin-2-ones with ethyl allenoate, catalyzed by the...
Scheme 6: Asymmetric [3 + 2] annulations of 2,6-diarylidenecyclohexanones with allenoates, catalyzed by the c...
Scheme 7: Asymmetric [3 + 2] annulations of allenoate with alkylidene azlactones, catalyzed by the chiral bin...
Scheme 8: Asymmetric [3 + 2] annulations of C60 with allenoates, catalyzed by the chiral phosphine B6.
Scheme 9: Asymmetric [3 + 2] annulations of α,β-unsaturated esters and ketones with an allenoate, catalyzed b...
Scheme 10: Asymmetric [3 + 2] annulations of exocyclic enones with allenoates, catalyzed by the ferrocene-modi...
Scheme 11: Asymmetric [3 + 2] annulations of enones with an allenylphosphonate, catalyzed by the ferrocene-mod...
Scheme 12: Asymmetric [3 + 2] annulations of 3-alkylidene-oxindoles with ethyl allenoate, catalyzed by the fer...
Scheme 13: Asymmetric [3 + 2] annulations of dibenzylideneacetones with ethyl allenoate, catalyzed by the ferr...
Scheme 14: Asymmetric [3 + 2] annulations of trisubstituted alkenes with ethyl allenoate, catalyzed by the fer...
Scheme 15: Asymmetric [3 + 2] annulations of 2,6-diarylidenecyclohexanones with allenoates, catalyzed by the f...
Scheme 16: Asymmetric [3 + 2] annulations of α,β-unsaturated ketones with ethyl allenoates, catalyzed by the f...
Scheme 17: Asymmetric [3 + 2] annulations of α,β-unsaturated esters with allenoates, catalyzed by the ferrocen...
Scheme 18: Asymmetric [3 + 2] annulations of alkylidene azlactones with allenoates, catalyzed by the chiral sp...
Scheme 19: Asymmetric [3 + 2] annulations of α-trimethylsilyl allenones and electron-deficient olefins, cataly...
Scheme 20: Asymmetric [3 + 2] annulations of α,β-unsaturated ketones with an allenone, catalyzed by the chiral...
Scheme 21: Asymmetric [3 + 2] annulations of cyclic enones with allenoates, catalyzed by the chiral α-amino ac...
Scheme 22: Asymmetric [3 + 2] annulations of arylidenemalononitriles and analogues with an allenoate, catalyze...
Scheme 23: Asymmetric [3 + 2] annulations of α,β-unsaturated esters with an allenoate, catalyzed by the chiral...
Scheme 24: Asymmetric [3 + 2] annulations of 3,5-dimethyl-1H-pyrazole-derived acrylamides with an allenoate, c...
Scheme 25: Asymmetric [3 + 2] annulations of maleimides with allenoates, catalyzed by the chiral phosphine H10....
Scheme 26: Asymmetric [3 + 2] annulations of α-substituted acrylates with allenoate, catalyzed by the chiral p...
Scheme 27: Asymmetric [3 + 2] annulation of an N-tosylimine with an allenoate, catalyzed by the chiral phosphi...
Scheme 28: Asymmetric [3 + 2] annulations of N-tosylimines with an allenoate, catalyzed by the chiral phosphin...
Scheme 29: Asymmetric [3 + 2] annulations of N-tosylimines with an allenoate, catalyzed by the chiral phosphin...
Scheme 30: Asymmetric [3 + 2] annulations of N-diphenylphosphinoyl aromatic imines with butynoates, catalyzed ...
Scheme 31: Asymmetric [3 + 2] annulations of N-tosylimines with allenylphosphonates, catalyzed by the chiral p...
Scheme 32: Asymmetric [3 + 2] annulation of an N-tosylimine with an allenoate, catalyzed by the chiral phosphi...
Scheme 33: Asymmetric [3 + 2] annulations of N-diphenylphosphinoyl aromatic imines with allenoates (top), cata...
Scheme 34: Asymmetric [3 + 2] annulation of N-diphenylphosphinoylimines with allenoates, catalyzed by the chir...
Scheme 35: Asymmetric [3 + 2] annulation of an azomethine imine with an allenoate, catalyzed by the chiral pho...
Scheme 36: Asymmetric [3 + 2] annulations between α,β-unsaturated esters/ketones and 3-butynoates, catalyzed b...
Scheme 37: Asymmetric intramolecular [3 + 2] annulations of electron-deficient alkenes and MBH carbonates, cat...
Scheme 38: Asymmetric [3 + 2] annulations of methyleneindolinone and methylenebenzofuranone derivatives with M...
Scheme 39: Asymmetric [3 + 2] annulations of activated isatin-based alkenes with MBH carbonates, catalyzed by ...
Scheme 40: Asymmetric [3 + 2] annulations of maleimides with MBH carbonates, catalyzed by the chiral phosphine ...
Scheme 41: A series of [3 + 2] annulations of various activated alkenes with MBH carbonates, catalyzed by the ...
Scheme 42: Asymmetric [3 + 2] annulations of an alkyne with isatins, catalyzed by the chiral phosphine F1.
Scheme 43: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphine B1.
Scheme 44: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphine H5.
Scheme 45: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphines H13 and H12.
Scheme 46: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphine H6.
Scheme 47: Kerrigan’s [2 + 2] annulations of ketenes with imines, catalyzed by the chiral phosphine B7.
Scheme 48: Asymmetric [4 + 1] annulations, catalyzed by the chiral phosphine G6.
Scheme 49: Asymmetric homodimerization of ketenes, catalyzed by the chiral phosphine F5 and F6.
Scheme 50: Aza-MBH/Michael reactions, catalyzed by the chiral phosphine G1.
Scheme 51: Tandem RC/Michael additions, catalyzed by the chiral phosphine H14.
Scheme 52: Intramolecular tandem RC/Michael addition, catalyzed by the chiral phosphine H15.
Scheme 53: Double-Michael addition, catalyzed by the chiral aminophosphine G9.
Scheme 54: Tandem Michael addition/Wittig olefinations, mediated by the chiral phosphine BIPHEP.
Scheme 55: Asymmetric Michael additions, catalyzed by the chiral phosphines H7, H8, and H9.
Scheme 56: Asymmetric γ-umpolung additions, catalyzed by the chiral phosphine A1.
Scheme 57: Asymmetric γ-umpolung additions, catalyzed by the chiral phosphines E2 and E3.
Scheme 58: Intramolecular γ-additions of hydroxy-2-alkynoates, catalyzed by the chiral phosphine D2.
Scheme 59: Intra-/intermolecular γ-additions, catalyzed by the chiral phosphine D2.
Scheme 60: Intermolecular γ-additions, catalyzed by the chiral phosphines B5 and B3.
Scheme 61: Intermolecular γ-additions, catalyzed by the chiral phosphines E6 and B4.
Scheme 62: Asymmetric allylic substitution of MBH acetates, catalyzed by the chiral phosphine G2.
Scheme 63: Allylic substitutions between MBH acetates or carbonates and an array of nucleophiles, catalyzed by...
Scheme 64: Asymmetric acylation of diols, catalyzed by the chiral phosphines E4 and E5.
Scheme 65: Kinetic resolution of secondary alcohols, catalyzed by the chiral phosphine E8 and E9.
Organocatalytic tandem Michael addition reactions: A powerful access to the enantioselective synthesis of functionalized chromenes, thiochromenes and 1,2-dihydroquinolines
- Chittaranjan Bhanja,
- Satyaban Jena,
- Sabita Nayak and
- Seetaram Mohapatra
Beilstein J. Org. Chem. 2012, 8, 1668–1694, doi:10.3762/bjoc.8.191
- and high enantiomeric excess of 4H-chromenes 6 with a wide range of substrates (Scheme 6). The potential of less well-explored alkynals as Michael acceptors was further explored, when Alemán et al. [48] in 2010 reported the synthesis of chiral 4-amino-4H-chromene 8 by reaction of salicyl-N-tosylimine
- by Xu and co-workers. Chiral secondary amine promoted oxa-Michael–aldol cascade reactions as reported by Wang and co-workers. Reaction of salicyl-N-tosylimine with aldehydes by domino oxa-Michael/aza-Baylis–Hillman reaction, as reported by Alemán and co-workers. Silyl prolinol ether-catalyzed oxa
Graphical Abstract
Figure 1: Some representative molecules having chromene, thiochromene or 1,2-dihydroquinolin structural motif...
Figure 2: Screened chiral proline and its derivatives as organocatalysts. Rb = rubidium.
Figure 3: Screened chiral bifunctional thiourea, its derivatives, cinchona alkaloids and other organocatalyst...
Scheme 1: Diarylprolinolether-catalyzed tandem oxa-Michael–aldol reaction reported by Arvidsson.
Scheme 2: Tandem oxa-Michael–aldol reaction developed by Córdova.
Scheme 3: Domino oxa-Michael-aldol reaction developed by Wei and Wang.
Scheme 4: Chiral amine/chiral acid catalyzed tandem oxa-Michael–aldol reaction developed by Xu et al.
Scheme 5: Modified diarylproline ether as amino catalyst in oxa-Michael–aldol reaction as reported by Xu and ...
Scheme 6: Chiral secondary amine promoted oxa-Michael–aldol cascade reactions as reported by Wang and co-work...
Scheme 7: Reaction of salicyl-N-tosylimine with aldehydes by domino oxa-Michael/aza-Baylis–Hillman reaction, ...
Scheme 8: Silyl prolinol ether-catalyzed oxa-Michael–aldol tandem reaction of alkynals with salicylaldehydes ...
Scheme 9: Oxa-Michael–aldol sequence for the synthesis of tetrahydroxanthones developed by Córdova.
Scheme 10: Synthesis of tetrahydroxanthones developed by Xu.
Scheme 11: Diphenylpyrrolinol trimethylsilyl ether catalyzed oxa-Michael–Michael–Michael–aldol reaction for th...
Scheme 12: Enantioselective cascade oxa-Michael–Michael reaction of alkynals with 2-(E)-(2-nitrovinyl)-phenols...
Scheme 13: Domino oxa-Michael–Michael–Michael–aldol reaction of 2-(2-nitrovinyl)-benzene-1,4-diol with α,β-uns...
Scheme 14: Tandem oxa-Michael–Henry reaction catalyzed by organocatalyst and salicylic acid, as reported by Xu....
Scheme 15: Asymmetric synthesis of nitrochromenes from salicylaldehydes and β-nitrostyrene, as reported by San...
Scheme 16: Domino Michael–aldol reaction between salicyaldehydes with β-nitrostyrene, as reported by Das and c...
Scheme 17: Enantioselective synthesis of 2-aryl-3-nitro-2H-chromenes, as reported by Schreiner.
Scheme 18: (S)-diphenylpyrrolinol silyl ether-promoted cascade thio-Michael–aldol reactions, as reported by Wa...
Scheme 19: Organocatalytic asymmetric domino Michael–aldol condensation of mercaptobenzaldehyde and α,β-unsatu...
Scheme 20: Organocatalytic asymmetric domino Michael–aldol condensation between mercaptobenzaldehyde and α,β-u...
Scheme 21: Hydrogen-bond-mediated Michael–aldol reaction of 2-mercaptobenzaldehyde with α,β-unsaturated oxazol...
Scheme 22: Domino Michael–aldol reaction of 2-mercaptobenzaldehydes with maleimides catalyzed by cinchona alka...
Scheme 23: Domino thio-Michael–aldol reaction between 2-mercaptoacetophenone and enals developed by Córdova an...
Scheme 24: Enantioselective tandem Michael–Henry reaction of 2-mercaptobenzaldehyde with β-nitrostyrenes repor...
Scheme 25: Enantioselective tandem Michael–Knoevenagel reaction between 2-mercaptobenzaldehydes and benzyliden...
Scheme 26: Cinchona alkaloid thiourea catalyzed Michael–Michael cascade reaction, as reported by Wang and co-w...
Scheme 27: Domino aza-Michael–aldol reaction between 2-aminobenzaldehydes and α,β-unsaturated aldehydes, as re...
Scheme 28: (S)-Diphenylprolinol TES ether-promoted aza-Michael–aldol cascade reaction, as developed by Wang’s ...
Scheme 29: Domino aza-Michael–aldol reaction reported by Hamada.
Scheme 30: Organocatalytic asymmetric synthesis of 3-nitro-1,2-dihydroquinolines by a dual activation protocol...
Scheme 31: Asymmetric synthesis of 3-nitro-1,2-dihydroquinolines by cascade aza-Michael–Henry–dehydration reac...
