S-functionalized internal olefins, that is, α-oxo ketene dithioacetals, was efficiently achieved with alcohols as the alkoxylating agents, (diacetoxyiodo)benzene (PhI(OAc)2) as the oxidant, and benzoquinone (BQ) as the co-oxidant. The alkoxylated olefins were thus constructed and applied for the synthesis of alkoxylated N-heterocycles. Polarization of the olefinic carbon-carbon doublebond by the electron-donating
CuCl2 and CuBr2-mediated intramolecular oxidative C–H/N–H cross-coupling/halogenation of β-thioalkyl-α-alkenoyl ketene N,S-acetals provides a new concise synthetic route to pyrrolones.
Direct Synthesis of Highly Substituted 2-Cyclohexenones and Sterically Hindered Benzophenones Based on a [5C + 1C] Annulation
作者:Zhenqian Fu、Mang Wang、Ying Dong、Jun Liu、Qun Liu
DOI:10.1021/jo9013386
日期:2009.8.21
DMF at room temperature, highly substituted 2-cyclohexenones 3 were synthesized in high to excellent diastereoselectivities with high yields. On the basis of this strategy, stericallyhindered benzophenones 4 were conveniently prepared via the iodonation−aromatization of 2-cyclohexenones 3 with I2 in MeONa/MeOH basic medium. Furthermore, benzophenones 4 were also obtained directly from 1 and 2 following
S-acetals) under mild conditions. Simple treatment of such enaminones with PhI(OAc)2 at ambient temperature in air afforded diverse multiply functionalized α,β-unsaturatedamides including β-cyclopropylated acrylamides, in which a wide array of functional groups such as aryl, (hetero)aryl, alkenyl, and alkyl can be conveniently introduced to a ketene moiety. The reaction mechanism was investigated by exploring