Regioselective Carboxylation of Silicon-Stabilized Allylic Carbanions and the Synthetic Utility of 2-Silyl-3-butenoates

Article abstract of DOI:10.1246/bcsj.59.2471

Carbanions of allylic dimethylphenylsilanes show remarkable regioselectivity toward carboxylation with carbon dioxide and methylation with methyl iodide.Methylationn of these compounds occurred preferentially at α position, although allyltrimethylsilane and allyltriphenylsilane are known to give γ selectivity toward the same electrophiles.Moreover, their aluminum "ate" complexes react with carbon dioxide regioselectively at the α position irrespective of methyl substitution pattern of the allylic moieties.The α-carboxylated allylic silanes proved to be useful synthons of 3-(methoxycarbonyl)allyl anions after esterifiaction.