- Catalytic Asymmetric Additions of Enol Silanes to In Situ Generated Cyclic, Aliphatic N-Acyliminium Ions
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Strong and confined imidodiphosphorimidate (IDPi) catalysts enable highly enantioselective substitutions of cyclic, aliphatic hemiaminal ethers with enol silanes. 2-Substituted pyrrolidines, piperidines, and azepanes are obtained with high enantioselectiv
- Aukland, Miles H.,Grossmann, Oleg,Lee, Sunggi,List, Benjamin,Maji, Rajat
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supporting information
(2022/01/19)
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- Photochemical rearrangement of N-mesyloxylactams: Stereospecific formation of N-heterocycles
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N-Mesyloxylactams undergo an efficient ring-contraction to N-heterocycles of various ring sizes. Yields increase with the degree of substitution α to the carbonyl. The stereochemical information of a chiral migrating carbon is conserved making this reacti
- Drouin, Alexandre,Winter, Dana K.,Pichette, Simon,Aubert-Nicol, Samuel,Lessard, Jean,Spino, Claude
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p. 164 - 169
(2011/03/19)
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- Photochemical rearrangement of N -chlorolactams: A route to N -heterocycles through concerted ring contraction
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We report a novel ring contraction allowing the direct conversion of N-chlorolactams to their corresponding ring-contraction N-heterocycles upon photolysis. Results show that the rearrangement occurs with a variety of N-chlorolactams and that the greater the substitution at the migrating carbon, the greater the yield of product. Importantly, stereochemistry at the migrating carbon is conserved in the product. Rearranged products were isolated as their methyl carbamates in yields varying from 17% to 58%, with the major side product being the recyclable parent lactam.
- Winter, Dana K.,Drouin, Alexandre,Lessard, Jean,Spino, Claude
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supporting information; experimental part
p. 2610 - 2618
(2010/06/17)
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- One-pot conversion of proline derivatives into iodinated iminosugar-based nucleosides, useful precursors of highly functionalized nucleoside analogues
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Readily available proline derivatives can be transformed in one step into β-iodinated iminosugar-based nucleosides, under very mild conditions. The method couples a tandem radical decarboxylation-oxidation-β-iodination to the addition of nitrogen bases. T
- Boto, Alicia,Hernandez, Dacil,Hernandez, Rosendo
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scheme or table
p. 6633 - 6642
(2011/02/25)
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- Electrochemical deallylation of α-allyl cyclic amines and synthesis of optically active quaternary cyclic amino acids
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Electrochemical oxidation of α-allylated and α-betizylated N-acylated cyclic amines by using a graphite anode easily affords the corresponding α-methoxylated products with up to 76% yield. Ease of oxidation was affected by the type of electrode, the size
- Kirira, Peter G.,Kuriyama, Masami,Onomura, Osamu
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experimental part
p. 3970 - 3982
(2010/07/04)
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- The Mannich-type reaction between N,O-acetals and carbon nucleophiles under solvent-free conditions
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The Mannich-type reaction for 1-methoxycarbonyl- or 1-benzyloxy-carbonyl-2-methoxylpyrrolidine with carbon nucleophiles such as acetylacetone, methyl acetoacetate, dimethyl malonates, benzoylacetone, dibenzoylmethane, or cyclohexane-1, 3-dione proceeded b
- Matsumura, Yoshihiro,Ikeda, Takashi,Onomura, Osamu
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p. 113 - 117
(2007/10/03)
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- Microflow electroorganic synthesis without supporting electrolyte
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Anodic methoxylation of several organic compounds has been successfully achieved in the absence of intentionally added supporting electrolyte using an electrochemical microflow system. The Royal Society of Chemistry 2005.
- Horcajada, Roberto,Okajima, Masayuki,Suga, Seiji,Yoshida, Jun-Ichi
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p. 1303 - 1305
(2008/09/16)
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- A convenient method for synthesis of optically active methylphenidate from N-methoxycarbonylpiperidine by utilizing electrochemical oxidation and Evans aldol-type reaction
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A new method to prepare optically active methylphenidate starting from piperidine is described. The method consists of a transformation of N-methoxycarbonylated piperidine to the corresponding α-methoxylated carbamate utilizing electrochemical oxidation f
- Matsumura, Yoshihiro,Kanda, Yasuhisa,Shirai, Kimihiro,Onomura, Osamu,Maki, Toshihide
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p. 7411 - 7422
(2007/10/03)
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- Tandem radical decarboxylation-oxidation of amino acids: A mild and efficient method for the generation of N-acyliminium ions and their nucleophilic trapping
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A convenient methodology for the synthesis of 2-substituted pyrrolidines from α-amino acids is described. A number of cyclic and acyclic α-amino acid derivatives have been prepared in order to test the scope and diastereoselectivity of this method. These substrates were treated with iodosylbenzene or (diacetoxyiodo)benzene (DIB) and iodine in order to generate the corresponding carboxyl radical, which evolves by loss of carbon dioxide to produce a carbon radical which in turn undergoes oxidation to an N-acyliminium ion. This postulated intermediate could be trapped inter- or intramolecularly by oxygen, nitrogen and carbon nucleophiles. In the case of carbon nucleophiles, a Lewis acid is required for the concomitant carbon-carbon bond formation. High yields and modest diastereoselectivities were obtained. The present methodology was applied to the synthesis of ω-amino aldehydes or hemiaminals 8-14, 2-aminopyrrolidine derivative 15, aminolactone derivative 16, and azasugar analogues 17 and 18. When carbon nucleophiles were used, alkaloid precursors such as 2-allyl- or 2-alkylpyrrolidines 19-23 and 25 were obtained.
- Boto, Alicia,Hernandez, Rosendo,Suarez, Ernesto
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p. 4930 - 4937
(2007/10/03)
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- Oxidative decarboxylation of α-amino acids: A mild and efficient method for the generation of N-acyliminium ions
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The oxidative decarboxylation of α-amino acids using the system (diacetoxyiodo)benzene or iodosylbenzene and iodine proceeded smoothly at room temperature. The intermediacy of an N-acyliminium cation has been demonstrated through intermolecular and intram
- Boto, Alicia,Hernandez, Rosendo,Suarez, Ernesto
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p. 5945 - 5948
(2007/10/03)
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- Electroorganic chemistry 139. Electroreductive decyanation of nitriles and its application to synthesis of α-alkylamines
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Electroreduction of nitriles gave the corresponding decyanated products when Zn was used as the material of cathode in aprotic solvent (DMF or MeCN) containing Et4NOTs as a supporting electrolyte. Alkylation of amines at the α-position was effectively achieved by cyanation of amines at the α-position, and α-alkylation of the resultant α-amino nitriles followed by the electroreductive decyanation.
- Shono, Tatsuya,Terauchi, Jun,Kitayama, Kenji,Takeshima, Yo-Ichiro,Masumura, Yoshihiro
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p. 8253 - 8262
(2007/10/02)
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- A New Method of Formation of 9-Azabicyclononane Skeleton and Its Application to Synthesis of (+/-)-Anatoxin a
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9-Azabicyclo-nonane skeleton was formed in one step by Lewis acid promoted reaction between 1-methoxycarbonyl-2,5-dimethoxypyrrolidine and 1-ethoxy-1-trimethylsiloxy-1,4-pentadiene, and it was converted to (+/-)-anatoxin a.
- Shono, Tatsuya,Matsumura, Yoshihiro,Uchida, Kenshi,Tagami, Katsumi
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p. 919 - 922
(2007/10/02)
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- Electroorganic Chemistry. Part 80. α-Hydroxylation of N-Acylated Cyclic Amines and Utilization of the Products as Amino Aldehyde Equivalents
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A general method for the transformation of N-acylated cyclic amines (1) to amino aldehydes (4) was exploited.N-Benzoyl- or N-alkoxycarbonyl-α-methoxyamines (2) were prepared by anodic reaction of (1) in methanol.Treatment of (2) with dilute hydrochloric acid gave the corresponding α-hydroxylated compounds (3) which are amino aldehydes equivalents.The reaction of (3) with methoxycarbonylmethylenetriphenylphosphorane yielded ω-amino-α,β-unsaturated esters in satisfactory yields.
- Shono, Tatsuya,Matsumura, Yoshihiro,Kanazawa, Takenobu,Habuka, Masahiro,Uchida, Kenshi,Toyoda, Katsuya
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p. 2876 - 2889
(2007/10/02)
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- A GENERAL METHOD FOR THE SYNTHESIS OF INDOLES BEARING A VARIETY OF SUBSTITUENTS AT THE β-POSITION, AND ITS APPLICATION TO THE SYNTHESIS OF L-TRYPTOPHAN
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A general synthetic method of β-substituted indoles such as indolacetic acid, tryptamine and L-tryptophan has been exploited utilizing α-methoxylated amides, lactams, a carbamate, and sulfonamides, easily obtainable by an electrochemical method, as key intemediates.
- Shono, Tatsuya,Matsumura, Yoshihiro,Kanazawa, Takenobu
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p. 1259 - 1262
(2007/10/02)
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- A NEW SYNTHETIC METHOD OF 1-AZABICYCLOSYSTEMS
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A new method for the synthesis of bicyclic pyridinium salts from alicyclic amines and reduction of the salts to 1-azabicyclosystems has been exploited.
- Shono, Tatsuya,Matsumura, Yoshihiro,Tsubata, Kenji,Inoue, Kenji,Nishida, Ryoichi
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- Electroorganic Chemistry. 60. Electroorganic Synthesis of Enamides and Enecarbamates and Their Utilization in Organic Synthesis.
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A variety of enecarbamates and enamides were synthesized from α-methoxy carbamates and α-methoxy amides prepared by anodic methoxylation of amine derivatives.Some new carbon-carbon bond-forming reactions and hydroxylation at the β position of amines have been accomplished by using these enecarbamates and enamides as key intermediates.Also, new synthetic routes of nicotinaldehyde and pyrrole derivatives have been exploited by utilizing anodic dimethoxylation of carbamates of piperidine and pyrrolidine, respectively.
- Shono, Tatsuya,Matsumura, Yoshihiro,Tsubata, Kenji,Sugihara, Yoshihiro,Yamane, Shin-ichiro,et. al.
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p. 6697 - 6703
(2007/10/02)
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- A NEW SYNTHETIC METHOD OF α-AMINO ACIDS FROM α-METHOXYURETHANES
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Reaction of α-methoxyurethanes with phenylisocyanide gave the corresponding amides of α-amino acid in reasonable yields.
- Shono, Tatsuya,Matsumura, Yoshihiro,Tsubata, Kenji
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p. 2411 - 2412
(2007/10/02)
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- Electroorganic Chemistry. 46. A New Carbon-Carbon Bond Forming Reaction at the α-Position of Amines Utilizing Anodic Oxidation as a Key Step
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A new carbon-carbon bond forming reaction at the α-position of primary and secondary amines has been exploited.The method involves anodic oxidation of urethanes derived from the primary and secondary amines and subsequent acid-catalyzed reaction of the re
- Shono, Tatsuya,Matsumura, Yoshihiro,Tsubata, Kenji
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p. 1172 - 1176
(2007/10/02)
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