Article ID Journal Published Year Pages File Type
176510 Dyes and Pigments 2012 6 Pages PDF
Abstract

The ligand-free Pd-mediated reaction between styrene and a 6-bromo-2,2-diaryl-2H-[1]benzopyran proceeded anomalously to give a 2-(diarylmethyl)-5-styrylbenzofuran via a tandem Heck coupling – ring-contraction process; none of the styryl substituted 2,2-diaryl-2H-[1]benzopyran was observed. A 2,2-diaryl-6-styryl-2H-[1]benzopyran resulted from the condensation between 4-hydroxystilbene and a 1,1-diarylpropynol and which exhibited photochromism through the reversible electrocyclisation of the pyran unit; no isomerisation – electrocyclisation of the stilbene moiety was detected.

► Tandem palladium-catalysed, ligand-free Heck reaction — ring-contraction. ► Synthesis of photochromic 2,2-diaryl-2H-[1]benzopyrans. ► 2,2-Diaryl-6-styryl-2H-[1]benzopyrans display a relatively weak photochromic response. ► X-Ray crystal structure of a 5-styrylbenzofuran.

Related Topics
Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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