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Tang Y, Han R, Lv M, Chen Y, Yang P. Tandem synthesis of pyrroloisoquinolines through 5-endo iodolactamization, oxidative functionalization and α-amidoalkylation reaction. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.04.057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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2
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Speckamp WN, de Boer JJJ. Base-catalyzed carbon-carbon bond formation reactions of ω-hydroxylactams. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/recl.19831020906] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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3
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Brinkmeyer RS, Terando NH. Dimerization of pyrazolyl-5-hydroxypyrrolidinones to tetrazocines. J Heterocycl Chem 2009. [DOI: 10.1002/jhet.5570260636] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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4
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Kano S, Yuasa Y, Shibuya S. A Synthesis of Heterocyclic Fused Isoquinolines Through N-Acyliminium Ion Intermediates. SYNTHETIC COMMUN 2006. [DOI: 10.1080/00397918508063886] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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5
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Hanessian S, Tremblay M, Marzi M, Del Valle JR. Synthetic studies in the intramolecular carbocyclization of N-acyloxyiminium ions. Stereoelectronic and steric implications of nucleophilic alkene, alkyne, and allene tethers. J Org Chem 2005; 70:5070-85. [PMID: 15960507 DOI: 10.1021/jo050326w] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
N-Acyloxyiminium ions generated from 4-substituted l-pyroglutamic esters with 4-(3-butenyl), 4-(3-butynyl), 4-(3-cinnamylmethyl), and 4-allenic tethers undergo rapid Lewis acid mediated carbocyclization to give stereodefined azacyclic compounds depending on the nature of the nucleophilic tether. In general, reactions of alkenes and alkynes with terminal alkyl or aryl substituents, as well as allenes, proceed through transient vinylic carbocations that are attacked internally by the N-Boc group to give tricyclic dihydrooxazinones. Diastereotopic bis-4-(3-butenyl) and 4-(3-butynyl) tethers undergo stereochemically controlled attack favoring an antiperiplanar rather than synclinal approach to give enantiopure 6-halo octahydroindole-2-carboxylic acids and 6-halo hexahydroindole-2-carboxylic acids as their methyl esters, respectively. The aza bicyclic and tricyclic compounds are excellent scaffolds for diversification.
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Affiliation(s)
- Stephen Hanessian
- Department of Chemistry, Université de Montréal, C.P. 6128, Station Centre-ville, Montréal, Province of Quebec, H3C 3J7 Canada.
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6
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Adhikari R, Jones DA, Liepa AJ, Nearn RH. Synthesis of N-Substituted γ-Methylene γ-Lactams. Aust J Chem 2005. [DOI: 10.1071/ch05286] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
N-Substituted cyanoacetamides 1 were condensed with 1,2-diketones 2 under base catalysis to form γ-hydroxy γ-lactams 3. Treatment of 3 with acids gave novel fungicidal γ-methylene γ-lactams 4. The exocyclic double bond of 4b reacted reversibly with 4-toluene sulfinate.
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Jefford CW, Kubota T, Zaslona A. Intramolecular Carbenoid Reactions of Pyrrole Derivatives. A Total Synthesis of (±)-Ipalbidine. Helv Chim Acta 2004. [DOI: 10.1002/hlca.19860690828] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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8
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Maryanoff BE, Zhang HC, Cohen JH, Turchi IJ, Maryanoff CA. Cyclizations of N-acyliminium ions. Chem Rev 2004; 104:1431-628. [PMID: 15008627 DOI: 10.1021/cr0306182] [Citation(s) in RCA: 551] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bruce E Maryanoff
- Johnson & Johnson Pharmaceutical Research & Development, Spring House, Pennsylvania 19477-0776, USA.
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Padwa A, Rashatasakhon P, Rose M. Triflic anhydride mediated cyclization of 5-hydroxy-substituted pyrrolidinones for the preparation of alpha-trifluoromethylsulfonamido furans. J Org Chem 2003; 68:5139-46. [PMID: 12816468 DOI: 10.1021/jo0341970] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction of alpha-angelica lactone with alkylamines under aqueous conditions afforded 5-hydroxy-5-methylpyrrolidinones in high yield. When the reaction was carried out under anhydrous conditions, the only products obtained were the corresponding 4-oxopentanoic acid amides. Treatment of either class of compound with triflic anhydride (Tf(2)O) in pyridine resulted in the formation of various substituted sulfonamidofurans. The suggested mechanism involves initial formation of an iminium ion which is subsequently transformed into a transient imino triflate. Cyclization of the highly electrophilic imine onto the oxygen atom of the adjacent carbonyl group generates an imino dihydrofuran intermediate. This species reacts further with another equivalent of Tf(2)O to give the observed product. The nature of the Lewis acid used was found to affect the outcome of the cyclization reaction. In certain cases, the sulfonamide furan was utilized as a cycloaddition substrate for the synthesis of indolines and related heterocyclic systems.
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Affiliation(s)
- Albert Padwa
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
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Hucher N, Decroix B, Daïch A. Pi-aromatic and sulfur nucleophilic partners in cationic pi-cyclizations: intramolecular amidoalkylation and thioamidoalkylation cyclization via omega-carbinol lactams(1, 2). J Org Chem 2001; 66:4695-703. [PMID: 11421795 DOI: 10.1021/jo0156316] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
NaBH(4) reduction of imides 1 and 6a,b,c followed by a pi-cyclization of the resultant N-acyliminium ions, generated in trifluoroacetic acid conditions, afforded two positional isomers, isoindolobenzothiazolinones 4 and 8, respectively. These ring closures proceeded via an intramolecular alpha-amidoalkylation with the classical pi-aromatic or the atypical sulfur atom as an internal nucleophile. A ready access to the related six-membered N,S-heterocyclic compounds such as isoindolobenzothiazinones 20a and 21a is also described. During this reaction, we have shown that omega-carbinol lactam precursor 14a led to endocyclic and exocyclic N-acyliminium ions 18a and 19a in equilibrium via the cyclic aza-sulfonium ion A. The latter furnished the expected products 20a and 21a in good yields. Similarly, different omega-carbinol lactams 14b-e substituted at C-angular position afforded the corresponding isoindolobenzothiazinones 20b-e and 21b-e bearing an angular alkyl, aralkyl, or aryl group. In the case of methyl 14b and benzyl 14e groups, an additional amount of the dehydration products 16b and 31 was isolated. These results indicate that the isomerization-pi-cyclization takes place via the cleavage of the thioether linkage in acidic medium.
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Affiliation(s)
- N Hucher
- Laboratoire de Chimie, URCOM, Faculté des Sciences & Techniques de l'Université du Havre, 25, rue Philippe Lebon, B.P: 540, F-76058 Le Havre Cedex, France
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11
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12
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Newly intramolecular α-amidoalkylation cyclisation: Use of theN-acyliminium ion with a sulfur atom as a nucleophile. Tetrahedron Lett 1999. [DOI: 10.1016/s0040-4039(99)00484-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Brodney MA, Padwa A. Generation and Trapping of N-Acyliminium Ions Derived from Isomünchnone Cycloadducts. A Versatile Route to Functionalized Heterocycles. J Org Chem 1999. [DOI: 10.1021/jo981624e] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Albert Padwa
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
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Hucher N, Daïch A, Decroix B. Synthesis of isoindolo[1,3]benzoxazine derivatives through intramolecular arylation ofN-acyliminium ions. J Heterocycl Chem 1998. [DOI: 10.1002/jhet.5570350644] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Wu XD, Khim SK, Zhang X, Cederstrom EM, Mariano PS. An Oxidative Mannich Cyclization Methodology for the Stereocontrolled Synthesis of Highly Functionalized Piperidines. J Org Chem 1998; 63:841-859. [PMID: 11672082 DOI: 10.1021/jo971706n] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Studies focusing on the development and application of a new oxidative methodology for promoting Mannich cyclizations have been conducted. The general features of these processes were explored with selected alpha-silylamino and alpha-silylamido allyl- and vinylsilanes. Representative conditions for affecting conversion of the alpha-silylamine and -amide functionalities into intermediate N-alkyl and N-acyliminium cations involve either 9,10-dicyanoanthracene SET-sensitized photooxidation or ceric ammonium or tetra-n-butylammonium nitrate oxidations. The applicability of these procedures for promoting Mannich cyclizations was first demonstrated by the preparation of methylidenepiperidines and -hydroazepines. Further studies have led to observations which show that Mannich cyclizations of stereochemically labeled alpha-silylamino vinylsilanes proceed to furnish tetrahydropyridines. Also, unlike their amine analogues, alpha-silylamido (E)-vinylsilanes undergo cyclization to produce tetrahydropyridines with retention of absolute and relative stereochemistry. The differences are due to the fact that N-acyliminium cations serve as intermediates in reactions of the alpha-silylamide systems. Moreover, the oxidation procedure is ideally suited for intermediate N-acyliminium cation generation in stereocontrolled reactions of alpha-silylamido allylsilanes. Finally, the preparative utility of the new cyclization method, when used in conjunction with an alpha-amino acid based strategy for substrate generation, was demonstrated by applications in concise routes for the synthesis of the aza-sugars, (-)-1-deoxymannojirimycin and (+)-1-deoxyallonojirimycin.
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Affiliation(s)
- Xiao-Dong Wu
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
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Padwa A, Hennig R, Kappe CO, Reger TS. A Triple Cascade Sequence as a Strategy for the Construction of the Erythrinane Skeleton. J Org Chem 1998. [DOI: 10.1021/jo9716183] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Albert Padwa
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - Rudiger Hennig
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - C. Oliver Kappe
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
| | - Thomas S. Reger
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
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Korenova A, Netchitailo P, Decroix B. Synthesis of 2,3-dihydro-3-hydroxy-2-(pyrrol-1-ylmethyl)-1H-isoindol-1-one. An intermediate for the synthesis of tetracyclic systems. J Heterocycl Chem 1998. [DOI: 10.1002/jhet.5570350102] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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18
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Brodney MA, Padwa A. Electrophilic Aromatic Substitution on Pyridine Rings. Intramolecular Cyclization Using N-Acyliminium Ions. Tetrahedron Lett 1997. [DOI: 10.1016/s0040-4039(97)01422-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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19
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Fisher MJ, Gunn BP, Um S, Jakubowski JA. An acyliminium ion approach towards the synthesis of β-substituted 3,4-dihydroisoquinolone propionates. Tetrahedron Lett 1997. [DOI: 10.1016/s0040-4039(97)01285-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Pigeon P, Decroix B. Introduction of a Carboxymethylamino(or oxy Or thio) Group in the 3 Position of 2-Aryl(or Arylmethyl)isoindol-1-ones from α Hydroxylactams. SYNTHETIC COMMUN 1997. [DOI: 10.1080/00397919708006073] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Padwa A, Brodney MA, Marino JP, Osterhout MH, Price AT. Tandem Dipolar Cycloaddition-Mannich Cyclization as an Approach to Tricyclic Nitrogen Heterocycles. J Org Chem 1997; 62:67-77. [PMID: 11671365 DOI: 10.1021/jo9607267] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of 2-diazo-N-[2-(3,4-dimethoxyphenyl)ethyl]-N-hept-6-enoylmalonamides were prepared and treated with a catalytic amount of rhodium(II) perfluorobutyrate. The resultant carbenoids undergo facile cyclization onto the neighboring amide carbonyl oxygen atom to generate isomünchnone-type intermediates. Subsequent 1,3-dipolar cycloaddition across the pendant olefin affords intramolecular cycloadducts in high yield. Exposure of these cycloadducts to boron trifluoride etherate results in a Lewis acid-induced ring opening to generate N-acyliminium ions which then undergo Mannich cyclization onto the neighboring pi-framework attached to the amide nitrogen atom. The cis stereochemistry of the resulting A/B ring fusion is analogous to similar erythrinane products obtained via a Mondon-enamide-type cyclization. The stereochemical assignment of the final cyclized products was determined by X-ray crystallography. Molecular mechanics calculations show that the ground state energy of the cis-fused diastereomer is 4.6 kcal lower than that of the trans diastereomer, and presumably some of this thermodynamic energy difference is reflected in the transition state for cyclization. In certain cases, proton loss from the initially formed N-acyliminium ion occurs prior to cyclization to give acyl enamides which subsequently cyclize producing epimeric products.
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Affiliation(s)
- Albert Padwa
- Department of Chemistry, Emory University, Atlanta, Georgia 30322
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22
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Manteca I, Sotomayor N, Villa MJ, Lete E. Tandem carbophilic addition-N-acyliminium ion cyclization for the synthesis of functionalized pyrrolo[2,1-a]isoquinolones: Key intermediates for the preparation of Erythrina-type alkaloids. Tetrahedron Lett 1996. [DOI: 10.1016/0040-4039(96)01745-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Murahashi SI. Synthetische Aspekte metallkatalysierter Oxidationen von Aminen und verwandte Reaktionen. Angew Chem Int Ed Engl 1995. [DOI: 10.1002/ange.19951072205] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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24
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Bahajaj AA, Hitchings GJ, Moore MH, Vernon JM. Unexpected formation and crystal structure of a spiro[indene-1,7′(6′H)pyrrolo[3,4-b]pyridin]-5′-one. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/p19940001211] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Konopíková M, Fišera L, Prónayová N, Ertl P. Regio- and Stereoselective Reduction of 3,5-Disubstituted 3a,6a-Dihydro-4H-pyrrolo[3,4-d]isoxazole-4,6(5H)-diones with Sodium Borohydride. European J Org Chem 1993. [DOI: 10.1002/jlac.1993199301168] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Mulzer J, Shanyoor M. Highly diastereoselective synthesis of (−)-petasinecine via Ireland-Claisen-type rearrangement. Tetrahedron Lett 1993. [DOI: 10.1016/0040-4039(93)88100-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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27
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Funke W, Hornig K, Würthwein EU, Möller MH. Alkoxy-substitutedN-acyliminium salts — synthesis, structure, reactivity. ACTA ACUST UNITED AC 1993. [DOI: 10.1002/cber.19931260917] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Harrowven DC. Michael initiated ring closure reactions in natural product synthesis: a concise entry to the podophyllins. Tetrahedron 1993. [DOI: 10.1016/s0040-4020(01)91221-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Moeller KD, Hanau CE. Reductive routes to rigid peptide building blocks: The dependence of a regioselective imide reduction on the nature of an α-alkoxy substituent. Tetrahedron Lett 1992. [DOI: 10.1016/s0040-4039(00)60001-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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32
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Lewis acid-promoted direct substitution of 4-methoxy- and 4-phenylthio-2-oxazolidinones by alkyl cuprates. Facile preparation of (3s,4s)-statine and (3s,4s)-cyclohexylstatine. Tetrahedron Lett 1991. [DOI: 10.1016/0040-4039(91)80822-n] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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33
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Goto T, Utsunomiya S, Aiba H, Hayasaka H, Endo M, Watanabe R, Ishizaki T, Sato R, Saito M. Synthesis of 7-Substituted 6,7-Dihydro-5H-pyrrolo[3,4-b]pyridin-5-ones. Reaction of 7-Hydroxy Derivatives with Nucleophiles. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1991. [DOI: 10.1246/bcsj.64.1901] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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34
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Brown DS, Charreau P, Hansson T, Ley SV. Substitution reactions of 2-phenylsulphonyl-piperidines and -pyrrolidines with carbon nucleophiles: Synthesis of the pyrrolidine alkaloids norruspoline and ruspolinone. Tetrahedron 1991. [DOI: 10.1016/s0040-4020(01)86388-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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35
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Jochims JC, Glocker MO, Hofmann J, Fischer H. N-acyliminium salts from the reaction of nitrilium salts with aldehydes. Tetrahedron 1991. [DOI: 10.1016/s0040-4020(01)80917-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Nagao Y, Dai WM, Ochiai M, Shiro M. Diastereoselective alkylation of chiral tin (II) enolates onto cyclic acyl iminium ions. Asymmetric total synthesis of (-)-supinidine. Tetrahedron 1990. [DOI: 10.1016/s0040-4020(01)96008-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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37
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Herborn C, Zietlow A, Steckhan E. (4RS,5R)- and (4RS,5S)-4-Methoxy-5-methyloxazolidin-2-one Derivatives of Threonine?Interesting Chiral Amidoalkylating Reagents. ACTA ACUST UNITED AC 1989. [DOI: 10.1002/anie.198913991] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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38
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Herborn C, Zietlow A, Steckhan E. (4RS,5R)- und (4RS,5S)-4-Methoxy-5-methyloxazolidin-2-on-Derivate aus Threonin - interessante chirale Amidoalkylierungsreagentien. Angew Chem Int Ed Engl 1989. [DOI: 10.1002/ange.19891011016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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39
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Goto T, Konno M, Saito M, Sato R. Magnesium Ion Assisted Highly Regio- and Chemoselective Reduction of 5H-Pyrrolo[3,4-b]pyridine-5,7(6H)-diones with Sodium Borohydride. A Convenient Synthesis of 6,7-Dihydro-7-hydroxy-5H-pyrrolo[3,4-b]pyridin-5-ones. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1989. [DOI: 10.1246/bcsj.62.1205] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Earley WG, Oh T, Overman LE. Synthesis studies directed toward gelsemine. Preparation of an advanced pentacyclic intermediate. Tetrahedron Lett 1988. [DOI: 10.1016/s0040-4039(00)82114-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Belen'Kii L. The Literature of Heterocyclic Chemistry, Part III. ADVANCES IN HETEROCYCLIC CHEMISTRY VOLUME 44 1988. [DOI: 10.1016/s0065-2725(08)60264-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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42
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Torii S, Inokuchi T, Takagishi S, Akahoshi F, Uneyama K. Regioselective Alkylation of VinylogousN-Acyliminium Ion, Leading to 6-Alkyl-1,2,3,6-tetrahydropyridines, by Using Electrogenerated Acid (EG acid) as a Catalyst. CHEM LETT 1987. [DOI: 10.1246/cl.1987.639] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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43
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Kano S, Yokomatsu T, Nemoto H, Shibuya S. EFFECT OF A-STRAIN. DIASTEREOSELECTIVE SYNTHESIS OF 3,2′-METHYLENE BRIDGEDCIS-4a-ARYLDECAHYDROISOQUINOLINE RING SYSTEM VIAN-ACYLIMINIUM ION-POLYENE RING CLOSURE. CHEM LETT 1986. [DOI: 10.1246/cl.1986.143] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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44
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Howard AS, Michael JP. Chapter 3 Simple Indolizidine and Quinolizidine Alkaloids. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/s0099-9598(08)60115-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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Westling M, Livinghouse T. Intramolecular cyclizations of α-ketoimidoyl halides derived from organic isonitriles. An expedient approach to the synthesis of 1-acyl-3,4-dihydroisoquinolines. Tetrahedron Lett 1985. [DOI: 10.1016/s0040-4039(00)98215-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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