Stereoconvergent Synthesis of Z-1,3-Disubstituted-1,3-Dienes by Uphill Photocatalysis
Graphical Abstract
Isomeric mixtures of 1,3-dienes were selectively isomerized to their Z-isomers by uphill photocatalysis using blue LEDs and a catalytic amount of Ru(bpy)32+(PF6−)2 as the triplet sensitizer. It proved possible to directly convert alkyne and 1-alkene to Z-1,3-dienes by a one-pot procedure, offering a practical approach to Z-1,3-dienes which cannot be made directly by ene-yne metathesis.
Abstract
A variety of 1-aryl-1,3-dienes were isomerized from E to Z isomers by photocatalysis using Ru(bpy)3[PF6]2 and blue LED light. Enrichment of the Z-isomer is thought to occur by selective triplet energy transfer from the photocatalyst to the stereoisomeric mixture. The 1,3-diene starting materials are easily made by catalytic ene-yne metathesis (EYM). To access 1,3-diene Z-stereoisomers directly, a one pot procedure was developed. Additional 1,3-dienes were investigated for both isomerization and Z-enrichment. The combination of cross EYM with photocatalysis allows for the stereoconvergent synthesis of Z-1,3-dienes.
Conflict of interest
The authors declare no conflict of interest.
Open Research
Data Availability Statement
The data that support the findings of this study are available in the supplementary material of this article.
