Iodine catalyses the acetylation of amines, phenols
and alcohols, including tertiary ones, with acetic anhydride in
excellent yield.
碘催化胺类、酚类和醇类(包括叔醇)与乙酸酐的乙酰化反应,产率极高。
LITHOGRAPHIC PRINTING PLATE PRECURSORS AND PROCESSES FOR PREPARING LITHOGRAPHIC PRINTING PLATES
申请人:FUJIFILM Corporation
公开号:US20150044612A1
公开(公告)日:2015-02-12
Lithographic printing plates and processes for preparing the lithographic printing plates are provided. The plates have excellent printing durability, staining resistance and staining resistance over time. The lithographic printing plate precursor includes: a substrate; a photosensitive layer provided on the substrate; and an extra layer optionally provided between the substrate and the photosensitive layer. The photosensitive layer or the extra layer adjacent to the substrate contains (A) a copolymer. The copolymer (A) includes: (a1) a repeating unit of formula (a1-1) below in a side chain, and (a2) a repeating unit having at least one of the structures represented by formulae (a2-1) to (a2-6) shown in the specification in a side chain. L
1
, Z
1
, R
1
, and R
21
, R
22
and R
23
in formula (a1-1) and the variables in formulae (a2-1) to (a2-6) are as defined in the specification.
Cobalt(II) chloride catalyzed acylation of alcohols with acetic anhydride: scope and mechanism
作者:Javed Iqbal、Rajiv Ranjan Srivastava
DOI:10.1021/jo00033a020
日期:1992.3
Cobalt(II) chloride catalyzes the acetylation of a variety of alcohols with acetic anhydride in excellent yield. Primary hydroxyl groups can be selectively acylated in the presence of secondary and tertiary ones while the secondary hydroxyl groups can be preferentially acetylated in the presence of tertiary ones. Tertiary alcohols have been found to give ketones, acetoacetates, olefins, and diketene in addition to the acetate. The beta-hydroxy esters and ketones can be acylated under these conditions without any elimination, and this reaction has been compared with 4-(dimethylamino)pyridine (DMAP)-mediated acylations where elimination of the resulting beta-acetoxy carbonyl compound is observed. A detailed investigation of the acylation of tertiary alcohols has revealed that these reactions proceed via a tertiary alkoxy radical and ketene. A mechanism for these acylations is proposed by invoking an electron-transfer process.