enones present as s-trans conformers to provide good yields of the silyl enol ethers of beta-acetylido carbonyl compounds. Typically good substrates are 2-cyclopentenone, 2-cyclohexenone, alpha,beta-unsaturatedaldehydes, and beta-alkoxy-alpha-enones. Copper acetylide reagents prepared from CuI and an alkynyllithium give considerably higher yields than those prepared from CuBr or CuCN. Iodotrimethylsilane
On the conjugate addition of tetraorganothallium ate complexes
作者:István E Marko、François Rebière
DOI:10.1016/s0040-4039(00)91727-1
日期:1992.3
Tetraorganothallium atecomplexes have been prepared and reacted with enones to afford either the [1,2] or [1,4] addition product. Mixed atecomplexes display high levels of chemoselectivity in the transfer of one of their ligands.