Unusual and Unexpected Reactivity of <i>t-</i>Butyl Dicarbonate (Boc<sub>2</sub>O) with Alcohols in the Presence of Magnesium Perchlorate. A New and General Route to <i>t-</i>Butyl Ethers
[reaction: see text] A new mild method for protecting alcohols as t-butylethers is reported. The reaction proceeds with Mg(ClO4)2 and Boc2O and shows general applicability. The deprotection of t-butylethers has also been revisited. Preliminary results indicate the CeCl3 x 7H2O/NaI system is a very suitable catalyst for their removal.
[反应:见正文]据报道,一种新的温和的保护叔丁醚醇的方法。反应与Mg(ClO4)2和Boc2O进行,显示出一般的适用性。也已经重新考虑了叔丁基醚的脱保护。初步结果表明,CeCl3 x 7H2O / NaI体系是非常适合去除它们的催化剂。
Iron(III)-Catalyzed Nucleophilic Substitution of the Hydroxy Group in Benzoin by Alcohols
作者:Joseph Samec、Anvar Mirzaei、Srijit Biswas
DOI:10.1055/s-0031-1289738
日期:2012.4
etherification reaction between benzoin derivatives and alcohols catalyzed by iron(III) proceeds in moderate to good yields. Other metal complexes showed either low reactivity or low chemoselectivity where oxidation of benzoin to benzil was a competing reaction. The iron source operated as a catalyst where 5 mol% of iron(III) generate the 2-alkoxy-1,2-diphenylethan-1-one in 50% yield. With an optimum
N-alkylindolylidene and N-alkylbenzothiazolylidene alkanones as sensitizers for photopolymer compositions
申请人:E.I. DU PONT DE NEMOURS AND COMPANY
公开号:EP0103294A1
公开(公告)日:1984-03-21
Photopolymerizable compositions comprising (a) at least one ethylenically unsaturated compound, (b) at least one photoinitiator or photoinitiator system, (c) sensitizing amount of an N-alkylindolylidene or N-alkylbenzothiazolylidene alkanone as defined, and optionally (d) at least one organic polymeric binder. The compositions, in layer form are useful in printing plates, litho films, photoresists, solder mask and for making image proofs. The products show sensitization to visible light.
Modified polysiloxane-coated sanitary rubber article and process for its production
申请人:DAIKYO GOMU SEIKO LTD.
公开号:EP0296878A2
公开(公告)日:1988-12-28
A sanitary rubber article having an improved surface property which is useful as rubber parts of medical instruments or machines and as rubber articles for medicaments is provided. This sanitary rubber article is coated, through bridging and bonding, with a modified polysiloxane composition comprising a modified polysiloxane having at least one modifying group selected from alkenyl, acryloyl, vinyloxy, maleimide and phenylketone groups in the molecule. A process for producing the article is also described.
Disclosed is a photosensitive composition used for offset printing, which provides an offset printing plate with excellent durability and developability. The photosensitive composition comprising:
(I) a film-forming binder resin,
(II) a photosensitive substance, and
(III) a microgel having a particle size of 0.01 to 2.0 µ prepared by emulsion polymerization using a polymeric emulsifier having Sp value of 9 to 16.