- Chemical Upcycling of Waste Poly(bisphenol A carbonate) to 1,4,2-Dioxazol-5-ones and One-Pot C?H Amidation
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Chemical upcycling of poly(bisphenol A carbonate) (PC) was achieved in this study with hydroxamic acid nucleophiles, giving rise to synthetically valuable 1,4,2-dioxazol-5-ones and bisphenol A. Using 1,5,7-triazabicyclo[4.4.0]-dec-5-ene (TBD), non-green carbodiimidazole or phosgene carbonylation agents used in conventional dioxazolone synthesis were successfully replaced with PC, and environmentally harmful bisphenol A was simultaneously recovered. Assorted hydroxamic acids exhibited good-to-excellent efficiencies and green chemical features, promising broad synthetic application scope. In addition, a green aryl amide synthesis process was developed, involving one-pot depolymerization from polycarbonate to dioxazolone followed by rhodium-catalyzed C?H amidation, including gram-scale examples with used compact discs.
- Jung, Hyun Jin,Park, Sora,Lee, Hyun Sub,Shin, Hyun Gyu,Yoo, Yeji,Baral, Ek Raj,Lee, Jun Hee,Kwak, Jaesung,Kim, Jeung Gon
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p. 4301 - 4306
(2021/07/09)
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- COMPOUND, PHOTOSENSITIVE RESIN COMPOSITION AND METHOD FOR FORMING RESIST FILM
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PROBLEM TO BE SOLVED: To provide a new compound capable of acting as a dissolution inhibitor in a positive photosensitive resin composition that shows high resolution and achieves a high alkali dissolution rate in an exposed portion while suppressing diss
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Paragraph 0043-0046
(2019/09/20)
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- METHOD FOR PRODUCING POLYCARBONATE OLIGOMERS
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A process for producing an oligomer comprising contacting a dialkyl carbonate and a dihydroxy compound in a reaction zone in the presence of an oligomerization catalyst under oligomerization conditions to form the oligomer wherein the molar ratio of dihydroxy compound to dialkyl carbonate in the reaction zone is at least 2:1.
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Page/Page column 9
(2017/07/14)
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- Study on the reaction between bisphenol A and dimethyl carbonate over organotin oxide
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Organotin oxide was used to catalyze the reaction between BPA (bisphenol A) and DMC (dimethyl carbonate), and Ph2SnO (diphenyltin oxide) displays the excellent catalytic performance in transesterification and O-methylation. However, Bu2SnO (dibutyltin oxide), (PhCH 2)2SnO (dibenzyltin oxide) and (C6H 11)2SnO (dicyclohexyltin oxide) exhibited weaker catalytic activity but higher selectivity for C-methylation product formation. The π-π function between Ph2SnO and BPA provided more chances for their interaction, and π-d interaction between phenyl ring and Sn resulted in catalyst having higher activity in transesterification and O-methylation. O-methylation product formation over Ph2SnO comes from transesterification product decomposition not from direct methylation of BPA with DMC.
- He, Xiaolong,Li, Zhenhuan,Su, Kunmei,Cheng, Bowen,Ming, Jun
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- Studies on the carboxymethylation and methylation of bisphenol A with dimethyl carbonate over TiO2/SBA-15
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Carboxymethylated species were selectively synthesized from dimethyl carbonate (DMC) and bisphenol A (BPA) over TiO2/SBA-15. On the basis of catalyst characterization by means of XRD, FT-IR, HPLC and GC-MS, the relations between catalytic performance and catalyst properties were discussed. Si-O-Ti was active sites for reaction, and the interaction mode between Ti-O-Si and DMC was main factor to determine carboxymethylation and methylation. When DMC was attacked by Ti-O-Si on two oxygen atoms of CH3-O moiety, BPA attacked carbonyl carbon to form carboxymethylated products. If the interaction occurs through the oxygen of C{double bond, long}O moiety, BPA attacked methyl carbon to form methylated products. Chemisorbed H2O over TiO2/SBA-15 made DMC to act as methylating agent. After chemisorbed H2O was removed, carboxymethylated species of two-methylcarbonate-ended-BPA (DmC(1)) and one-methylcarbonate-ended-BPA (MmC(1)) were selectively synthesized.
- Su, Kunmei,Li, Zhenhuan,Cheng, Bowen,liao, Kun,Shen, Dexin,Wang, Yufei
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experimental part
p. 60 - 68
(2010/04/25)
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- Optically active compound and photosensitive resin composition
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A photoactive compound is used in combination with a photosensitizer, represented by the following formula (1): A?[(J)m?(X-Pro)]n ??(1) wherein A represents a hydrophobic unit comprising at least one kind of hydrophobic groups selected from a hydrocarbon group and a heterocyclic group, J represents a connecting group, X-Pro represents a hydrophilic group protected by a protective group Pro which is removable by light exposure, m represents 0 or 1, and n represents an integer of not less than 1. The protective group Pro may be removable by light exposure in association with the photosensitizer (especially, a photo acid generator), or may be a hydrophobic protective group. The hydrophilic group may be a hydroxyl group or a carboxyl group. The photoactive compound has high sensitivity to a light source of short wavelength beams, for resist application, therefore, the photoactive compound is advantageously used for forming a pattern with high resolution.
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- Vacuum-UV influenced design of polymers and dissolution inhibitors for next generation photolithography
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An overview of our 157 nm photoresist development activities is presented. Examination of the vacuum ultraviolet (VUV) absorbances of fluorinated monomers and polymers has provided knowledge that influenced copolymer design so that resist transparency in the vacuum-UV can be maximized. Partially fluorinated norbornenes and tricyclononenes (TCNs) have been incorporated into copolymers using metal-catalyzed addition and radical initiators. These materials have orders of magnitude higher transparency at 157 nm compared to their hydrocarbon analogues as measured by variable angle spectroscopic ellipsometry (VASE). We have also synthesized fluorinated dissolution inhibitors for use in a three-component resist system. The results of preliminary lithographic evaluations of resists formulated from these polymers are presented.
- Trinque, Brian C.,Chambers, Charles R.,Osborn, Brian P.,Callahan, Ryan P.,Lee, Geun Su,Kusumoto, Shiro,Sanders, Daniel P.,Grubbs, Robert H.,Conley, Willard E.,Willson, C. Grant
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- Specific ortho effect in acylation of o-carboranediol
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o-Carboranediol is acylated fast and in a high yield with glycol chloroformates under conditions of the Schotten-Baumann reaction catalyzed by tertiary amines (general basic catalysis) through formation of a complex of the diol with the triethylamne catalyst, detected by 1H NMR spectroscopy. For m-carboranediol the nucleophilic mechanism of catalysis is preferable, through a complex of pyridine catalyst with chloroformate. The complex of the catalyst with o-carboranediol involves both OH groups of the diol (1 : 1 complex), owing to their ortho arrangement, that is, a specific ortho effect takes place. The ortho effect is responsible for different reactivities of two HO groups of o-carboranediol: Under mild conditions, only one OH group enters the reaction. The "phenolic" character of o-carboranediol is manifested in the acid-catalyzed esterification with carboxylic acids or anhydrides.
- Shashkova,Koval'chuk,Zapadinskii
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p. 225 - 234
(2007/10/03)
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