- A study of diketopiperazines as electron-donor initiators in transition metal-free haloarene-arene coupling
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Several diketopiperazines have been shown to promote carbon-carbon coupling between benzene and aryl halides in the presence of potassium tert-butoxide and without the assistance of a transition metal catalyst. The structure of the diketopiperazine has an influence on its reductive potential and can help to promote the coupling of the more challenging aryl bromides with benzene.
- Cumine, Florimond,Zhou, Shengze,Tuttle, Tell,Murphy, John A.
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p. 3324 - 3336
(2017/04/21)
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- From amines to diketopiperazines: a one-pot approach
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An efficient one-pot synthesis is described for the preparation of 1,4-disubstituted piperazine-2,5-diones starting from a suitable amine and chloroacetyl chloride in the presence of an aqueous base. The resulting chloroacetamide is cyclised in situ by employing the phase-transfer (PT) catalyst, benzyltriethylammonium chloride (TEBA). The products are isolated in excellent yields of up to 90%.
- O'Reilly, Elaine,Pes, Lara,Paradisi, Francesca
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experimental part
p. 1696 - 1697
(2010/04/29)
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- One-step diketopiperazine synthesis using phase transfer catalysis
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A simple and efficient one-step procedure is described for the synthesis of a number of symmetrical 1,4-disubstituted piperazine-2,5-diones under phase transfer conditions. The reactions are carried out at room temperature, starting from a suitable N-chloroacetamide in the presence of an aqueous solution of sodium hydroxide. Piperazine-2,5-diones were obtained with excellent selectivity in yields of up to 90%.
- O'Reilly, Elaine,Lestini, Elena,Balducci, Daniele,Paradisi, Francesca
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experimental part
p. 1748 - 1750
(2009/07/05)
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- Triazenes as robust and simple linkers for amines in solid-phase organic synthesis
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A new linker strategy for the attachment of aliphatic amines has been developed. Starting from Merrifield resin, an immobilized diazonium salt was prepared in two steps. Reaction of various amines gave rise to triazenes, which in turn were cleaved off upon treament with mild acids. The triazenes have been proven to be base stable and were used in various types of transformations. The overall process is high-yielding and efficient.
- Braese, Stefan,Koebberling, Johannes,Enders, Dieter,Lazny, Ryszard,Wang, Mingfei,Brandtner, Siegfried
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p. 2105 - 2108
(2007/10/03)
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- Triazenes: A useful protecting strategy for sensitive secondary amines
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The application of aryl triazene as a protecting group for sensitive secondary amines such as 4-piperidone (2) is described. The triazene protected amine is compatible with oxidative and reductive conditions as well as with lithiating and alkylating reagents. The free amine is regenerated by treatment with trifluoroacetic acid.
- Lazny, Ryszard,Poplawski, Janusz,K?bberling, Johannes,Enders, Dieter,Br?se, Stefan
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p. 1304 - 1306
(2007/10/03)
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- Electrochemical Studies on Haloamides. Part 3. Haloacetamides and Haloacetohydroxamates
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The electrochemical reduction of haloacetamides and acetohydroxamates 1 and 2 at a mercury cathode in DMF-0.1 mol dm-3 TEAP (tetraethylammonium perchlorate) solutions has been investigated.The reduction leads to the corresponding dehalogenated products together with cyclic dimers, arising from follow-up reactions of the conjugated base of the starting compound.The same type of products, but in quite different yield, are formed when ethyl isobutyrate anion is electrogenerated in the presence of chloro derivatives 1.The reactivity of the substrates, and in particular the structure of the dimers, primarily depends on the nature of the substituent at the amide nitrogen.Possible reaction pathways leading to the products are suggested.
- Casadei, Maria Antonietta,Rienzo, Barbara Di,Inesi, Achille,Moracci, Franco Micheletti
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p. 375 - 378
(2007/10/02)
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- BASE-PROMOTED CYCLOCOUPLING REACTION OF 2-BROMOPROPANAMIDES AND 2-BROMOACETAMIDES WITH DMF
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In the presence of a suitable base, representative 2-bromopropanamides 4 and 2-bromoacetamides 5 undergo cyclocondensation onto the carbonyl group of DMF to yield the 2-(dimethylamino)oxazolidin-4-ones 6 and 10, respectively.Of these cyclic orthoester ami
- D'Angeli, Ferrucio,Cavicchioni, Giorgio,Catelani, Giorgio,Marchetti, Paolo,Maran, Flavio
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p. 471 - 474
(2007/10/02)
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- TOTAL SYNTHESIS OF BICYCLOMYCIN
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Total synthesis of (+/-)-bicyclomycin was achieved in 19 steps starting from diketopyperazine.
- Nakatsuka, Shin-ichi,Yamada, Kozi,Yoshida, Kumi,Asano, Osamu,Murakami, Yoshihiro,Goto, Toshio
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p. 5627 - 5630
(2007/10/02)
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- Base-promoted Reactions of α-Halogeno-alkylanilides
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Hydride-promoted reactions of 2-halogeno-alkylcarboxanilides afford heterocyclic and acyclic condensation products, some of the latter compounds arising upon hydrolysis and/or rearrangement of the former ones.Competitive formation of dioxopiperazines versus oxazolidinone derivatives or their transformation products depends mainly upon the nature (primary, secondary or tertiary) of the halide moiety.Concurrent dehydrohalogenation of 2-bromo-isobutyranilides leads to unsaturated condensation products.
- Cavicchioni, Giorgio,Scrimin, Paolo,Veronese, Augusto C.,Balboni, Gianfranco,D'Angeli, Ferruccio
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p. 2969 - 2972
(2007/10/02)
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- Convenient Syntheses of Cyclic Carboxamides from α,β,γ,δ and ε-halocarboxamides under Phase Transfer Conditions
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Piperazine-2,5-diones (2) were prepared by N-alkylation between two molecules of α-halocarboxamides (1) in the presence of a phase transfer catalyst in yields of 64-88percent. β,γ,δ and ε-Lactams (6,9 and 13) were similarly synthesized by intramolecular N-alkylation of the corresponding halocarboxamides (5, 8 and 12) under phase transfer conditions in 53-99percent yields.Keywords--piperazine-2,5-dione; β-lactam; γ, δ, and ε lactams; bis-β-lactam; phase transfer catalyst; intramolecular N-alkylation
- Okawara, Tadashi,Matsuda, Takashi,Furukawa, Mitsuru
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p. 1225 - 1233
(2007/10/02)
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- CONVENIENT SYNTHESES OF PIPERAZINE-2,5-DIONES AND LACTAMS FROM HALOCARBOXAMIDES USING PHASE TRANSFER CATALYSTS
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Inter- and intramolecular N-alkylation of α-halocarboxamides and dihalocarboxamides in the presence of solid phase transfer catalyst led to the corresponding piperazine-2,5-diones (2) and lactams (4) in the yields of 64-88 and 63-99 percent, respectively.A one-pot synthesis of β-lactams (7) from α-methyl-α,β-dibromopropionyl chloride (5) and α-amino acid using phase transfer catalyst was also successfully achieved.
- Okawara, Tadashi,Noguchi, Yoshihide,Matsuda, Takashi,Furukawa, Mitsuro
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p. 185 - 188
(2007/10/02)
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