Samarium diiodide-promoted intramolecular ketone–ester coupling reaction: novel cyclization and ring expansion pathway
作者:Kazuki Iwaya、Momoe Nakamura、Eietsu Hasegawa
DOI:10.1016/s0040-4039(02)01007-9
日期:2002.7
2-substituted-1-indanone-2-carboxylates were treated with samarium diiodide (SmI2), ring expansion products such as 3-substituted-1,2-naphthoquinones were isolated. Alcohols were also obtained as the mixture of cis- and trans-isomers of hydroxy and ester substituents. A reaction mechanism involving intramolecular addition of samarium ketyl radicals to ester substituents followed by ring expansion was proposed
palladium-catalyzed Dowd–Beckwith ringexpansion/C–C bond formation cascade is described. A range of six to nine-membered β-alkenylated cyclic ketones possessing a quaternary carbon center were accessed under mild conditions. Besides styrenes, the electron-rich alkenes such as silyl enol ethers and enamides were also compatible, providing the desired β-alkylated cyclic ketones in moderate to good yields.