Regioselective (Biomimetic) Synthesis of a Pentasulfane from ortho-Benzoquinone
摘要:
A mechanism is proposed for the formation of cyclic 5,6,7,8,9-pentathiabenzocycloheptene-1,2-diol, 4, from the reaction of o-benzoquinone with reduced elemental sulfur, H2Sx. 1,6-Conjugate addition to the quinone is favored over 1,4-conjugate addition. Hydrogen bonding to the quinone oxygen enhances the nucleophilicity of H2Sx by facilitating the removal of the S-H proton. We propose that initially formed 3-polysulfidobenzene-diol intermediates are oxidized to their corresponding quinones and closure of the polysulfur ring subsequently takes place at the C3-C4 bond leading to 4. A possible mechanism for the formation of the pentasulfur linkage in 4 is discussed, which is the key moiety found in a number of natural products.
[EN] MODIFIED THIOXANTHONE PHOTOINITIATORS<br/>[FR] PHOTO-INITIATEURS À THIOXANTHONE MODIFIÉS
申请人:LINTFIELD LTD
公开号:WO2021144582A1
公开(公告)日:2021-07-22
Latent photoinitiator compounds are described, as well as compositions containing such compounds and their uses in photoinitated methods for producing photoresist structured.
Polymer stabilising compositions, polymers stabilised therewith and shaped articles formed from such polymers
申请人:MORTON THIOKOL, INC.
公开号:EP0062406A1
公开(公告)日:1982-10-13
Compositions which are effective in stabilizing polymers against the deteriorative effects of heat are provided comprising (1) an organic tin compound or mixture of organic tin compounds, (2) an organic compound having an aromatic ring which is substituted with a hydroxyl (-OH) group and a mercapto (-SH) group ortho to each other, and, optionally, (3) an organotin mercaptide or mixture of organotin mercaptides. Also provided are polymer compositions containing said stabilizers and articles of manufacture made from said stabilized polymer compositions.
Verfahren zur Herstellung von Polycarbonaten mit Sulfonanilid-Endgruppen
申请人:BAYER AG
公开号:EP0082383A1
公开(公告)日:1983-06-29
Die vorliegende Anmeldung beschreibt die Herstellung von aromatischen Polycarbonaten nach den bekannten Zweiphasen-Grenzflächenverfahren, ausgehend von Diphenolen dadurch gekennzeichnet, daß aromatische Sulfonanilide als Kettenabbrecher gebraucht werden uns zwar in Konzentrationen von 2 Mol% bis 20 Mol%, vorzugsweise in Konzentrationen von 2,5 Mol% bis 10 Mol%, bezogen auf die Mole der verwendeten Diphenolen. Zusätzlich bezieht sich die vorliegende Anmeldung auf aromatische Polycarbonate, die nach dem erfindungsgemäßen Herstellprozeß erhältlich sind. Die Produkte der vorliegenden Erfindung haben bessere selbstlöschende Eigenschaften im Vergleich zu Polycarbonaten ohne Sulfonamid-Endgruppen.
Halogen-containing polymers stabilized with organic antimony compound and an ortho mercapto phenol compound
申请人:MORTON THIOKOL, INC.
公开号:EP0134348A1
公开(公告)日:1985-03-20
Compositions which are effective in stabilizing polymers against the deteriorative effects of heat are provided comprising 1) an organic antimony compound or mixture of organic antimony compounds and 2) an organic compound or mixture of organic compounds having an aromatic ring which is substituted with hydroxy (-OH) and mercapto (-SH) groups ortho to each other. Also provided are polymer compositions containing said stabilizers and articles of manufacture made from said stabilized polymer compositions.
Polyol resins and coating compositions containing same
申请人:MITSUI SEKIYU KAGAKU KOGYO KABUSHIKI KAISHA
公开号:EP0211600A2
公开(公告)日:1987-02-25
Polyol resins are prepared from bisphenol type resins by at least two of the following processes:
1) chain extension
2) ring opening
3) esterification
The resulting resins are useful in the preparation of coating compositions with good water and corrosion resistance, good solvent compatability and a reduced tendency to foam.