2051-76-5Relevant articles and documents
Polymerization of free secondary amine bearing monomers by RAFT polymerization and other controlled radical techniques
Janoschka, Tobias,Teichler, Anke,Krieg, Andreas,Hager, Martin D.,Schubert, Ulrich S.
, p. 1394 - 1407 (2012)
This work describes the polymerization of the free secondary amine bearing monomer 2,2,6,6-tetramethylpiperidin-4-yl methacrylate (TMPMA) by means of different controlled radical polymerization techniques (ATRP, RAFT, NMP). In particular, reversible addition-fragmentation chain transfer (RAFT) polymerization enabled a good control at high conversions and a polydispersity index below 1.3, thereby enabling the preparation of well-defined polymers. Remarkably, the polymerization of the secondary amine bearing methacrylate monomer was not hindered by the presence of the free amine that commonly induces degradation of the RAFT reagent. Subsequent oxidation of the polymer yielded the polyradical poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate), which represents a valuable material used in catalysis as well as for modern batteries. The obtained polymers having a molar mass (Mn) of 10,000-20,000 g/mol were used to fabricate well-defined, radical-bearing polymer films by inkjet- printing.
Brotherton et al.
, p. 1283 (1961)
An efficient synthesis of chiral isoquinuclidines by Diels - Alder reaction using Lewis acid catalyst
Hirama, Masafumi,Kato, Yuji,Seki, Chigusa,Nakano, Hiroto,Takeshita, Mitsuhiro,Oshikiri, Noriko,Iyoda, Masahiko,Matsuyama, Haruo
, p. 7618 - 7624 (2010)
The Diels-Alder reaction of 1,2-dihydropyridine derivatives (1-phenoxycarbonyl-1,2-dihydropyridine 1 or 1-methoxycarbonyl-1,2- dihydropyridine 4) with N-acryloyl (1S)-2,10-camphorsultam (1S)-2 {or N-acryloyl (1R)-2,10-camphorsultam (1R)-2} in the presence of Lewis acid, such as titanium tetrachloride, zirconium tetrachloride, and hafnium tetrachloride afforded the endo-cycloaddition product, 2-azabicyclo[2.2.2]octane derivatives in good yields with excellent diastereoselectivity. The absolute stereochemistry assignment of the endo-cycloaddition product (1S)-5a starting from N-acryloyl (1S)-2,10-camphorsultam (1S)-2 has been established to be (1S,4R,7S) and the reaction mechanism was proposed.
Automated Assembly of Starch and Glycogen Polysaccharides
Delbianco, Martina,Seeberger, Peter H.,Zhu, Yuntao
supporting information, p. 9758 - 9768 (2021/06/30)
Polysaccharides are Nature's most abundant biomaterials essential for plant cell wall construction and energy storage. Seemingly minor structural differences result in entirely different functions: cellulose, a β (1-4) linked glucose polymer, forms fibrils that can support large trees, while amylose, an α (1-4) linked glucose polymer forms soft hollow fibers used for energy storage. A detailed understanding of polysaccharide structures requires pure materials that cannot be isolated from natural sources. Automated Glycan Assembly provides quick access to trans-linked glycans analogues of cellulose, but the stereoselective installation of multiple cis-glycosidic linkages present in amylose has not been possible to date. Here, we identify thioglycoside building blocks with different protecting group patterns that, in concert with temperature and solvent control, achieve excellent stereoselectivity during the synthesis of linear and branched α-glucan polymers with up to 20 cis-glycosidic linkages. The molecules prepared with the new method will serve as probes to understand the biosynthesis and the structure of α-glucans.
METHOD FOR PRODUCING (METH)ACRYLIC ACID ANHYDRIDE
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Paragraph 0024-0031; 0040, (2021/05/28)
PROBLEM TO BE SOLVED: To provide an industrially useful method for producing a (meth)acrylic acid anhydride capable of producing a (meth)acrylic acid anhydride with high yield and high purity. SOLUTION: There is provided a method for producing a (meth)acrylic acid anhydride by reacting a (meth)acrylic acid alkali metal salt and sulfonyl chloride in an organic solvent. The (meth)acrylic acid alkali metal salt includes lithium (meth)acrylate, sodium (meth)acrylate, potassium (meth)acrylate or the like. Among these (meth)acrylic acid alkali metal salts, preferable are sodium acrylate, potassium acrylate, sodium methacrylate and potassium methacrylate in consideration of market feedability, reactivity and easiness of treatment after the reaction. In addition, the sulfonyl chloride includes benzenesulfonyl chloride, p-toluenesulfonyl chloride and methanesulfonyl chloride. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT