The synthesis and photochromism of a 2,2-diaryl-6-styryl-2H-[1]benzopyran: Unexpected palladium-mediated ring-contraction of a 6-bromo-2,2-diaryl-2H-[1] benzopyran

Christopher D. Gabbutt, B. Mark Heron, Colin Kilner, Suresh B. Kolla

Research output: Contribution to journalArticle

5 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)825-830
Number of pages6
JournalDyes and Pigments
Issue number2
Publication statusPublished - 1 Feb 2012
Externally publishedYes


Cite this