Stereoselective Access to Fully Substituted Aldehyde‐Derived Silyl Enol Ethers by Iridium‐Catalyzed Alkene Isomerization
作者:Itai Massad、Heiko Sommer、Ilan Marek
DOI:10.1002/anie.202005058
日期:2020.9
An in situ generated cationic Ir‐catalyst isomerizes simple allylic silylethers into valuable, fully substituted aldehyde‐derived silylenolethers. Importantly, by judicious choice of substrate, either of the two possible stereoisomers of a given enolate derivative is accessible with complete stereoselectivity. One‐pot isomerization‐aldol and isomerization‐allylation processes illustrate the synthetic
Coating composition for use in producing an insulating thin film
申请人:——
公开号:US20040077757A1
公开(公告)日:2004-04-22
Disclosed is a coating composition comprising: (A) a silica precursor comprising at least one member selected from the group consisting of alkoxysilanes and hydrolysis/polycondensation products formed by hydrolysis/polycondensation reactions of the alkoxysilanes under acidic conditions, and (B) an organic polymer containing 20% by weight or more, based on the weight of the organic polymer, of an organic block copolymer, wherein the coating composition has an acidic pH value.
Also disclosed is a coating composition which, in addition to the above-mentioned silica precursor and organic polymer, comprises an acid having an electrolytic dissociation exponent (pKa) of from 1 to 11 and a quaternary ammonium salt.
Further, disclosed are a porous silica insulating thin film, a multilevel interconnect and a semiconductor device, which are obtained from the above-mentioned coating compositions.
Asymmetric Dehydrative Cyclization of ω-Hydroxy Allyl Alcohols Catalyzed by Ruthenium Complexes
作者:Shinji Tanaka、Tomoaki Seki、Masato Kitamura
DOI:10.1002/anie.200904671
日期:2009.11.9
New axially chiral ligands and their allyl esters have been designed and synthesized. The combination of these ligands with [CpRu(CH3CN)3]PF6 has realized highly efficient intramolecular dehydrative cylization of ω‐hydroxy allylalcohols, to give α‐alkenyl‐substituted cyclic ethers with up to greater than 99:1 enantiomeric ratio without activation of the allylic moieties (see scheme; Cp=cyclopentadienyl