1.4- Dicopper-1,3-butadienes

Transmetallation of 1,4-dilithio-l,3-butadienes with copper salt such as CuQ would lead to 1,4-dicopper-1,3-butadienes. Upon thermolysis or further treatment with other substrates, the organo-tf/-copper reagents could be transformed into a wide variety of compounds with interesting skeletons, which could be obtained by other methods or via the reactions of 1,4-dilithio-l,3-butadienes. 

Wei J, Wang Z, Zhang WX, Xi Z (2013) Construction of octa-alkyl substituted and deca-substituted all-cis octatetraenes via linear dimerization of 1,4-dicopper-1,3-butadienes and subsequent cross-coupling with halides. Org Lett 15 1222—1225... 

Dichloro[cate a-2-methyl-l,4-butadiene]dicopper(I) (B) can be prepared from direct reaction between isoprene and copper(I) chloride, analogously to the synthesis of the complex between butadiene and CuCl.12 The advantage of the synthesis described here is that the product is not contaminated with unreacted CuCl, and can be obtained as high-quality crystals instead of a microcrystalline powder. 

B. DICHLORO [catefia-2-METHYL-l,4-BUTADIENE]DICOPPER(I), CuzCUCCjHg)... 

The further reaction patterns of 1,4-dicopper-l,3-butadienes 54 were expanded by investigation of the annulation of 54 with carbon monoxide. This reaction led to cycloaddition reaction and afforded expected cyclopentadienones 20 as well as the... 

---