Synthesis and evaluation of photophysical properties of Series of π-conjugated oxazole dyes
摘要:
Incorporation of pi-conjugated spacers at the 2 or 5 position of a 2,5-disubstitutedaryloxazole led to new series of fluorescent dyes. They show emissions from visible to 700 nm along with significant Stokes shift up to 208 nm and a strong solvatochromic fluorescence. These compounds are easily accessible in one step through direct C-H bond functionalization. (C) 2013 Elsevier Ltd. All rights reserved.
Copper as a Powerful Catalyst in the Direct Alkynylation of Azoles
作者:François Besselièvre、Sandrine Piguel
DOI:10.1002/anie.200904776
日期:2009.12.7
Copper‐bottomed catalysis! The direct alkynylation of azolesthrough a copper‐based CH bond activation, using alkynylbromides as the coupling partner, has been developed (see scheme). The method is very rapid, is functional‐group tolerant, and provides a straightforward entry to diverse alkynyl heterocycles that is complementary to the Sonogashira reaction.
The copper-catalyzed directalkynylation of azoles with 1,1-dibromo-1-alkenes as electrophiles is described. These easily accessible substrates are a useful addition to the field of directalkynylations in an efficient and functional group tolerant reaction to provide a straightforward entry to diverse alkynyl heterocycles.