(equation presented) R1= aryl, allyl R2= methyl, 2,4-dimethyl-3-pentyl and (-)-menthyl Ruthenum(II) porphyrins and dirhodium(II) acetate catalyze cyclization of γ-alkoxy-α-diazo-β-ketoesters to (Z)-4-(alkyloxycarbonylmethylidene)-1,3-dioxolanes selectively (ca. 68% yield) with no formation of 3(2H)-furanones. Reacting a diazo ketoester with [RuII(TTP)(CO)] [H2TTP = meso-tetrakis(p-tolyl) porphyrin] in toluene afforded a ruthenium carbenoid complex, which has been isolated and spectroscopically characterized. A mechanism involving hydrogen atom migration from the C-H bond to the ruthenium carbenoid is proposed.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry