- METHOD FOR PREPARING A POLY(ETHER SULFONIMIDE OR -AMIDE) COPOLYMER USING CYCLIC OLIGOMERS
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Disclosed is a method for preparing a poly(ethersulfonimide or ethersulfonamide) copolymer using cyclic oligomers, and more particularly, to a method for preparing a poly(ethersulfonimide or ethersulfonamide) copolymer by preparing a cyclic ether sulfone oligomer and a cyclic imide or amide oligomer and subjecting the cyclic ether sulfone oligomer and the cyclic imide or amide oligomer to ring-opening copolymerization in the presence of an alkali metal fluoride catalyst.
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- Orthogonal Cu- and Pd-based catalyst systems for the O- and N-arylation of aminophenols
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O- or N-arylated aminophenol products constitute a common structural motif in various potentially useful therapeutic agents and/or drug candidates. We have developed a complementary set of Cu- and Pd-based catalyst systems for the selective O- and N-arylation of unprotected aminophenols using aryl halides. Selective O-arylation of 3- and 4-aminophenols is achieved with copper-catalyzed methods employing picolinic acid or CyDMEDA, trans-N,N′-dimethyl-1,2- cyclohexanediamine, respectively, as the ligand. The selective formation of N-arylated products of 3- and 4-aminophenols can be obtained with BrettPhos precatalyst, a biarylmonophosphine-based palladium catalyst. 2-Aminophenol can be selectively N-arylated with CuI, although no system for the selective O-arylation could be found. Coupling partners with diverse electronic properties and a variety of functional groups can be selectively transformed under these conditions.
- Maiti, Debabrata,Buchwald, Stephen L.
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supporting information; experimental part
p. 17423 - 17429
(2010/03/25)
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- Synthesis of phthalonitrile resins containing ether and imide linkages
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Imide-containing phthalonitrile monomers are prepared from a phthalonitrile and an aromatic dianhydride. The monomer and a method for preparing the monomer is disclosed. These monomers are synthesized into heat resistant polymers and copolymers with aromatic ring structure incorporating imide and ether linkages. The synthesis of the high temperature thermosetting polymers and copolymers is also disclosed.
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- Melt-fusible polyimides
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Melt-fusible polyimides based on pyromellitic dianhydride and at least one defined aromatic diamine are useful in making low-void composites and thermoplastic tapes, which can be fabricated into articles such as, for example, aircraft and autobody panels, printed circuit boards, etc. Some of these polyimides are melt-processible and can be fabricated by conventional procedures such as extrusion and injection molding.
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