Abstract
Ene-yne cross-metathesis from alkynes and ethylene is a useful method to produce substituted conjugated butadiene derivatives. If this method has been used with aliphatic alkynes, it has however never been used starting from diarylacetylenes as internal alkynes. We show that the ene-yne cross-metathesis catalyzed by the second generation Hoveyda ruthenium catalyst provides the 2,3-diarylbuta-1,3-dienes under 3 atm of ethylene at 100 °C. The scope and limitations of the reaction have been evaluated starting from unsymmetrical functionalized diarylacetylene derivatives hence leading to unsymmetrical 2,3-diarylbuta-1,3-dienes in a straightforward and environmentally acceptable manner.
Highlights
Depending on the substitution pattern of the 1,3-diene motif, different families of products in terms of electron delocalization are available. 2,3-Diarylbuta-1,3-dienes A consisting of branched π-electron frameworks are cross-conjugated compounds related to (4)-dendralenes featuring two terminal double bonds (Figure 1) [1], whereas 1,3-butadienes that are di-substituted in 1,4-position by aryl groups lead to highly conjugated compounds B with alternating single and double bonds
Report on on the application application of ruthenium-catalyzed ruthenium‐catalyzed ene‐yne cross-metathesis cross‐metathesis for the we we report for the we report on the the application of of ruthenium‐catalyzed ene-yne ene‐yne cross‐metathesis for the direct preparation of
The feasibility of the ene‐yne cross‐metathesis between 1,2‐diphenylacetylene with ethylene was first evaluated in the presence of the second generation Grubbs (I) and Hoveyda (II) ruthenium was first evaluated in the presence of the second generation Grubbs (I) and Hoveyda (II) ruthenium catalysts (Figure 2, Scheme 1)
Summary
Depending on the substitution pattern of the 1,3-diene motif, different families of products in terms of electron delocalization are available. 2,3-Diarylbuta-1,3-dienes A consisting of branched π-electron frameworks are cross-conjugated compounds related to (4)-dendralenes featuring two terminal double bonds (Figure 1) [1], whereas 1,3-butadienes that are di-substituted in 1,4-position by aryl groups lead to highly conjugated compounds B with alternating single and double bonds. The 1,1-, 1,2-, and 1,3-diphenylbuta-1,3-dienes (C–E) present at the same time three conjugated double bonds and a cross-conjugated (3)-dendralene structure. Because of their conjugated 1,3-diene structure, these products are perfect starting substrates for the construction of complex molecules [2,3,4]. 2-Aryl- and 2,3-diaryl-dienes of type A have been extensively studied for the access to cyclic products resulting from Diels–Alder [4,22]. They have been recently in iridium‐catalyzed hydrohydroxymethylation [25] and and hetero-Diels–Alder reactionsinvolved [23,24].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
