Oligothiophene-Linked Bisnaphthopyrans: Sequential and Temperature-Dependent Photochromism
作者:Weili Zhao、Erick M. Carreira
DOI:10.1002/chem.200600958
日期:2007.3.16
Photochromic bisnaphthopyrans linked with oligothiophenes were synthesized and their photochromic behavior studied. Sequential and temperature-dependentphotochromism was observed in the oligothiophene linked bisnaphthopyrans. The kinetics of photo and thermal processes in bisnaphthopyrans in comparison with naphthopyrans were studied. Substituent and linking effects on the photochromic properties
[reaction: see text]. Photochromic pyrans, including [3H]naphtho[2,1-b]pyrans, [2H]naphtho[1,2-b]pyrans, indeno-fused naphtho[1,2-b]pyrans, and heteroannulated pyrans, were synthesized in excellent yields through a facile one-pot procedure by reaction of propargyl alcohol and naphthol or phenol derivatives in the presence of 5 mol % PPTS and 2 equiv of (MeO)3CH. Symmetrical and nonsymmetrical bispyrans
Silver-Catalyzed Cross-Coupling of Propargylic Alcohols with Isocyanides: An Atom-Economical Synthesis of 2,3-Allenamides
作者:Jianquan Liu、Zhenhua Liu、Nannan Wu、Peiqiu Liao、Xihe Bi
DOI:10.1002/chem.201304255
日期:2014.2.17
Cross‐coupling reactions between propargylicalcohols and isocyanides, by means of silver catalysis, have been described. This new reaction is both atom and step efficient and is applicable to a broad scope of substrates, allowing the synthesis of a range of synthetically valuable 2,3‐allenamides in moderate to excellent yields.
Hydroxyl Assisted, Photoredox/Cobalt Co‐catalyzed Semi‐Hydrogenation and Tandem Cyclization of
<i>o</i>
‐Alkynylphenols for Access to 2,3‐Dihydrobenzofurans
Herein, a hydroxyl assisted, photoredox/cobalt co‐catalyzed semi‐hydrogenation and tandem cyclization of o‐alkynylphenols is developed towards direct assembly of 2,3‐dihydrobenzofurans. Moderate to good yields were obtained for a range of sterically and electronically diverse 2‐propynolphenols under mild conditions. Mechanistic studies demonstrated the inevitable role of the alcoholic hydroxyl group
Naphthopyrans annelated in C5-C6, their preparation and compositions and (CO)polymer matrices containing them
申请人:——
公开号:US20020197562A1
公开(公告)日:2002-12-26
The present invention relates to novel compounds of the naphthopyran type which have an annelated carbocycle in position 5,6. These compounds are of formula (I) given below:
1
in which A is an alicyclic ring which is optionally annelated with an aromatic ring and in which two adjacent R
3
can together form at least one ring, for example a benzo group. These compounds (I) possess interesting photochromic properties. The invention also relates to the method of preparing these compounds (I), as well as their applications as photochromes and compositions and (co)polymer matrices comprising them.