نتایج جستجو برای: copolyamide imides

تعداد نتایج: 737  

Journal: :Acta chimica Slovenica 2013
Melek Gul Irem Kulu Omer Tahir Gunkara Nuket Ocal

The C-C coupling of N,N'-bis(5-norbornene-2,3-dicarboximide) (3) and N,N'-bis(7-oxa-5-norbornene-2,3-dicarboximide) (6) with aryl and heteroaryl iodides gave under reductive Heck conditions the C-aryl(hetaryl), substituted N,N'-bistricyclic imides 7a-f and 8a,b. The fused spiro-1,3-indandionolylpyrrolidine compounds, 9, 10 and 11 were also obtained from ninhydrine, sarcosine and 3 or 6 via [3+2...

1999
David A. Evans Leester D. Wu John J. M. Wiener Jeffrey S. Johnson David H. B. Ripin Jason S. Tedrow

A general procedure for the synthesis of enantiopure â-substituted, â-amino acids is presented. Alkylation of the sodium enolates derived from chiral N-acyloxazolidinone imides 2 (R ) Me, i-Pr, t-Bu, Ph, Bn) with tert-butyl bromoacetate afforded the 2-substituted succinate derivatives 3 in good yields (82-89%) and with high selectivity (g93:7). Following hydrolysis, Curtius rearrangement of the...

Journal: :Zeitschrift fur Naturforschung. C, Journal of biosciences 2004
Silvia Regina Tozato Prado Valdir Cechinel-Filho Fátima Campos-Buzzi Rogério Corrêa Silvia Maria Correia Suter Cadena Maria Benigna Martinelli de Oliveira

Cyclic imides such as succinimides, maleimides, glutarimides, phthalimides and their derivatives contain an imide ring and a general structure -CO-N(R)-CO- that confers hydrophobicity and neutral characteristic. A diversity of biological activities and pharmaceutical uses have been attributed to them, such as antibacterial, antifungal, antinociceptive, anticonvulsant, antitumor. In spite of the...

Journal: :Discover chemical engineering 2023

Abstract Ammonia (NH 3 ) is a promising clean energy carrier, provided that its production driven by renewable rather than fossil fuel-based Haber–Bosch (H–B) process. Chemical looping ammonia synthesis (denoted as CLAS) can intervene in the ubiquitous scaling relations catalytic separately feeding reactants to nitrogen carrier achieve atmospheric operation, which provides an alternative synthe...

2013
Hans-Dietrich Stachel Josef Schachtner Josef Seidel

Z. Naturforsch. 51 b, 409-416 (1996); eingegangen am 28. Juni 1995 Reduction, Narthigenine, Butyrolactones, Butyrolactams, Tetramic Acids A series of potentially cytotoxic a,/?-unsaturated 7 -hydroxy-butyrolactones, -lactams and -thiolactones has been synthesized via regioselective hydride reduction of the appropriate maleic acid anhydrides, imides and thioanhydrides. By this means a straightfo...

Journal: :The Journal of organic chemistry 2007
Daniel H Paull Ethan Alden-Danforth Jamison Wolfer Cajetan Dogo-Isonagie Ciby J Abraham Thomas Lectka

A catalytic, asymmetric process for the synthesis of 1,4-benzoxazinones from o-benzoquinone imides and ketene enolates is reported. Addition of Lewis acids (Zn(OTf)2, In(OTf)3, and in particular Sc(OTf)3) creates a bifunctional catalytic system that dramatically increases the reaction rate and the yield of these non-natural amino acid precursors while preserving the remarkable enantioselectivit...

Journal: :Organic & biomolecular chemistry 2010
Shigeo Kohmoto Shugo Hisamatsu Hakuei Mitsuhashi Masahiro Takahashi Hyuma Masu Isao Azumaya Kentaro Yamaguchi Keiki Kishikawa

Intramolecular [2+2] photocycloaddition of aromatic chain imides possessing bis-phenanthrene moieties afforded straight and cross ring closure products. The ratio of cycloadducts was dependent on reaction time and temperature, which resulted in a reversal of regioselectivity. The reaction was proved to involve a retro cycloaddition. The cross ring closure products were formed predominantly in t...

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