Reactions of 1,4-dilithio-buta-1,3-dienes with iodomethane, and with other iodo compounds

ORGN 133

Paul F. Hudrlik, phudrlik@fac.howard.edu, Donghua Dai, dai_application@yahoo.com, and Anne M. Hudrlik, ahudrlik@howard.edu. Department of Chemistry, Howard University, 525 college street, NW, Washington D.C, DC 20059
Silole dianions have been of recent interest. One way to generate silole dianions involves the generation of 1,4-dilithiobuta-1,3-dienes. When 1,4-dilithio-1,2,3,4-tetraethyl-1,3-butadiene was treated with iodomethane, 1-iodo-4-methyl-1,2,3,4-tetraethyl-1,3-butadiene was obtained in good yields. The 1,4-dimethyl-1,2,3,4-tetraethyl-1,3-butadiene was never observed. A mechanistic study was carried out suggesting that the involvement of 1-methyl-4-lithio-1,2,3,4-tetraethyl-1,3-butadiene as an intermediate is likely, while the involvement of 1-iodo-4-lithio-1,2,3,4-tetraethyl-1,3-butadiene is unlikely.