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Volume 51, Issue 3
Displaying 1-6 of 6 articles from this issue
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Yoshiaki INAKI1993 Volume 51 Issue 3 Pages 188-202
Published: March 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSPyrimidine derivatives were found to be applicable to photoresists for microelectronics. This paper deals with synthesis and photochemistry of pyrimidine derivatives, and application to photoresists. Intermolecular photodimerization of pyrimidine bases in the side chains of various polymeric and dimeric compounds upon irradiation of UV light (270 nm) led to photocrosslinking of the polymer chains or photopolymerization of the dimeric compounds. These materials can be used as deep-UV negative type photoresists. On the other hand, the polymers containing thymine photodimers in the main chain underwent dissociation of the thymine photodimers upon irradiation to UV light (250 nm), leading to breakage of the polymer chains. These polymers could be used as positive type photoresists and high resolution (0.3μm) was demonstrated. Tautomerism of pyrimidine was also applied to a chemical amplification photoresist system. Polymers containing 2, 4-dialkoxypyrimidine derivatives that is an enol form of uracil were high sensitive deep-UV, and EB chemical amplification resists.View full abstractDownload PDF (1420K) -
Shoji EGUCHI, Takashi OKANO1993 Volume 51 Issue 3 Pages 203-211
Published: March 01, 1993
Released on J-STAGE: January 28, 2010
JOURNAL FREE ACCESSRecent advances in synthetic method of heterocyclic compounds by aza-Wittig reaction, i.e., the imination using iminophosphoranes, are here reviewed. Examples are systematically presented depending on the direct cyclization route by intramolecular aza-Wittig reaction, or the sequential route via intermolecular aza-Wittig reaction, followed by various types of cyclizations such as electrocyclic reaction, Diels-Alder cycloaddition, and nucleophilic heterocyclization etc. The feasibility of this method in synthesis of nitrogen-heterocycles is emphasized in this review.View full abstractDownload PDF (892K) -
Takeshi AKASAKA, Wataru ANDO1993 Volume 51 Issue 3 Pages 212-222
Published: March 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSRecent works on photosensitized oxygenation of organosulfur compounds are reviewed. In singlet oxygen oxidation of the designed sulfur compounds, the active oxidizing species much stronger than singlet oxygen itself and primary intermediates such as persulfoxide and thiadioxirane are formed as secondary intermediates, in which new types of active oxidizing species such as peroxysulfenic acid, S-hydroperoxysulfonium ylide, S-hydroperoxysulfurane and bis (alkanesulfenyl) peroxide are reported. These active oxidizing species can be used for an effective epoxidation of olefins. The current research interests in photosensitized oxygenation of organoselenium and organophosphorus compounds are also presented.View full abstractDownload PDF (1299K) -
Tsuneo IMAMOTO1993 Volume 51 Issue 3 Pages 223-231
Published: March 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSNew methods for the synthesis of phosphine-boranes including optically active ones have been established. Diphenylphosphine-borane and methyldiphenylphosphine-borane reacted with various electrophiles to give phosphine-borane derivatives having a functional group. Diastereomerically pure secondary phorphine-boranes, (Sp) -and (Rp) -menthyloxyphenylphosphine-boranes, were prepared from dichlorophenylphosphine. These secondary phosphine-boranes underwent stereospecific alkylation and arylation reactions. The phosphorus-oxygen bond of the resulting phosphine-boranes was reductively cleaved by lithium naphthalenide in an almost quantitative yield with virtually net retention of configuration. A new and efficient route to bidentate phosphine ligands with homochiral phosphine center has been established on the basis of these stereochemical studies on the substitution reactions at chiral phosphorus. Functionalizations of the boranato group of phosphine-boranes have been investigated. Trialkylphosphine-boranes reacted with methanesulfonic acid or trifluoromethanesulfonic acid with evolution of hydrogen The resulting sulfonates were subjected to nucleophilic substitution reactions with various nucleophiles including carbon nucleophiles. A new phosphine-borane having a P-B-P-B-P-B-P-B bond linkage was synthesized.View full abstractDownload PDF (933K) -
Kenji UNEYAMA1993 Volume 51 Issue 3 Pages 232-246
Published: March 01, 1993
Released on J-STAGE: January 28, 2010
JOURNAL FREE ACCESSMonofluorination is mainly classified into two types of reactions; electrophilic and nucleophilic fluorinations. Preparations of monofluorinated compounds by the use of monofluorocarbene intermediates and monofluorinated building blocks are also summarized. Recent.development of difluorination via difluorocarbene, substituted difluoromethyl radicals, transformations of carbonyl and methylene groups to difluoromethylene group along with utilization of the difluoromethylated building blocks has been reviewed.View full abstractDownload PDF (1732K) -
[in Japanese], [in Japanese], [in Japanese]1993 Volume 51 Issue 3 Pages 247
Published: March 01, 1993
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSDownload PDF (176K)
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