- Oxidative Generation of N-Acyliminium Ions from N-1-(Tributylstannyl)alkyl Carboxamides and Carbamates and Their Reactions with Carbon Nucleophiles
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Oxidation of N-1-(tributylstannyl)alkyl carboxamides and carbamates with ammonium hexanitratocerate (IV) or ferrocenium hexafluorophosphate generates their N-acyliminium ions by the elimination of tributylstannyl radical under mild reaction conditions.The
- Narasaka, Koichi,Kohno, Yasushi
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- Addition of carbon nucleophiles to cyclic N-acyliminium ions in SDS/water
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The acid-catalyzed addition of 1,3-dicarbonyl compounds and activated olefins (silyl enol ethers and ethyl vinyl ether) to N-Boc-2-methoxypyrrolidine (1a) and N-Boc-2-methoxypiperidine (1b) in SDS/water medium is described. Good yields of the correspondin
- Camilo, Nilton Soares,Pilli, Ronaldo Aloise
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- Gold(I)/(III)-catalyzed synthesis of 2-substituted piperidines; valency-controlled cyclization modes
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Strategic use of hard gold(III) and soft gold(I) catalysts provides facile access to two types of 2-substituted piperidines from propargylic alcohols. Thus, heating propargylic alcohols in the presence of AuBr3 results in cyclization to furnish
- Morita, Nobuyoshi,Tsunokake, Tomonori,Narikiyo, Yuji,Harada, Mayuka,Tachibana, Tatsuyuki,Saito, Yuta,Ban, Shintaro,Hashimoto, Yoshimitsu,Okamoto, Iwao,Tamura, Osamu
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- Synthesis of a 3,4-Dihydro-1,3-oxazin-2-ones Skeleton via an Intermolecular [4 + 2] Process of N-Acyliminium Ions with Ynamides/Terminal Alkynes
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An approach to access functionalized 3,4-dihydro-1,3-oxazin-2-ones has been developed by reacting semicyclic N,O-acetals 5 and 6 with ynamides 7 or terminal alkynes 8 in a one-pot fashion. The reaction went through a formal [4 + 2] cycloaddition process to generate a number of functionalized 3,4-dihydro-1,3-oxazin-2-ones 9a-9ak and 10a-10bc in yields of 34-97%. In addition, the utility of this transformation was demonstrated by the synthesis of (±)-sedamine 13.
- Han, Xiao-Li,Nie, Xiao-Di,Chen, Zhao-Dan,Si, Chang-Mei,Wei, Bang-Guo,Lin, Guo-Qiang
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p. 13567 - 13578
(2020/11/13)
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- Pd-catalyzed enantioselective aerobic oxidation of secondary alcohols: Applications to the total synthesis of alkaloids
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Enantioselective syntheses of the alkaloids (-)-aurantioclavine, (+)-amurensinine, (-)-lobeline, and (-)- and (+)-sedamine are described. The syntheses demonstrate the effectiveness of the Pd-catalyzed asymmetric oxidation of secondary alcohols in diverse contexts and the ability of this methodology to set the absolute configuration of multiple stereocenters in a single operation. The utility of an aryne C-C insertion reaction in accessing complex polycyclic frameworks is also described.
- Krishnan, Shyam,Bagdanoff, Jeffrey T.,Ebner, David C.,Ramtohul, Yeeman K.,Tambar, Uttam K.,Stoltz, Brian M.
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supporting information; experimental part
p. 13745 - 13754
(2009/02/06)
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- Addition of carbon nucleophiles to cyclic N-acyliminium and oxocarbenium ions under solvent-free conditions
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The InCl3-catalyzed addition of carbon nucleophiles to cyclic N-acyliminium and oxocarbenium ions under solvent-free conditions at room temperature is described. The corresponding α-substituted heterocycles were obtained in moderate to excellen
- de Godoy, Luiz Antonio F.,Camilo, Nilton Soares,Pilli, Ronaldo Aloise
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p. 7853 - 7856
(2007/10/03)
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- Addition of activated olefins to cyclic N-acyliminium ions in ionic liquids
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Organoindate(III) ionic liquid (BMI?InCl4) was successfully employed in the nucleophilic addition of allyltrimethylsilane, silyl enol ethers and ketene silyl acetals to in situ generated cyclic N-acyliminium ions at room temperature without the
- Pilli, Ronaldo Aloise,Robello, Luís Gustavo,Camilo, Nilton Soares,Dupont, Jairton,Moreira Lapis, Alexandre Augusto,Da Silveira Neto, Brenno A.
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p. 1669 - 1672
(2007/10/03)
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- Zinc triflate as Lewis acid in nucleophilic addition to cyclic N-acyliminium ions
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Zinc triflate-mediated nucleophilic addition of allytrimethylsilane, silyl enol ethers and terminal acetylenes to cyclic N-acyliminium ions at room temperature in CH2Cl2 is described. The corresponding α-substituted heterocycles were
- Pilli, Ronaldo Aloise,Robello, Luís Gustavo
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p. 2297 - 2300
(2007/10/03)
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- Trimethylsilyl trifluoromethanesulfonate (TMSOTf) catalyzed amidoalkylation of silylenolethers. Stereocontrolled syntheses of (+/-)-sedamine and (+/-)-norsedamine
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Trimethylsilyl trifluoromethanesulfonate (TMSOTf) catalyzed addition of 1-trimethylsilyloxy-1-phenylethene to N-ethoxycarbonyl- and N-tert-butoxycarbonyl-2-ethoxypiperidines (3a and 3b, respectively) afforded the corresponding ketocarbamates 4a and 4b, in excellent yields. Stereoselective conversion to (±)-norsedamine (7) and (±)-sedamine (8) is described.
- Pilli,Dias
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p. 2213 - 2229
(2007/10/02)
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