You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via7.6.11.17.3 Variation 3: Ethylmagnesiation of Alkynes
Please login to access the full content or check if you have access via
DOI:
10.1055/sos-SD-007-00562
Takahashi, T.; Liu, Y., Science of Synthesis, (2004) 7, 618.
Ethylmagnesiation of alkynes is rather difficult. One reason is that alkynes readily dimerize on zirconium(II) species to give zirconacyclopentadienes, which do not react with ethylmagnesium bromide. This reaction can be circumvented by the use of diynes, which do not dimerize. Octa-3,5-diyne (59) reacts with ethylmagnesium bromide in the presence of 30 mol% of dichlorobis(η5-cyclopentadienyl)zirconium(IV) in tetrahydrofuran at 50°C. The ethylmagnesiation product 60 is obtained in 70% yield (Scheme 43).[169]
Meeeee 88 Meeeeeeeeeeeeeeee ee ee Meeeee[888]
References
[169] | Meeeeeeee, M.; Meeeee, M.; Meeeeee, M.; Meeeee, M.; Meeeeeee, M.; Meeeeee, M., Meeeeeeeeee Meee., (8888) 88, 8888. |