Domino Reactions of 1,3-Bis-Silyl Enol Ethers with Benzopyrylium Triflates: Efficient Synthesis of Fluorescent 6H-Benzo[c]chromen-6-ones, Dibenzo[c,d]chromen-6-ones, and 2,3-Dihydro-1H-4,6-dioxachrysen-5-ones
作者:Bettina Appel、Nehad N. R. Saleh、Peter Langer
DOI:10.1002/chem.200501024
日期:2006.1.23
condensation of 1,3-bis-silyl enol ethers with benzopyrylium triflates, generated in situ by the reaction of chromones with Me3SiOTf, afforded functionalized 2,3-dihydrobenzopyrans; treatment of the latter with NEt3 or BBr3 resulted in a domino retro-Michael-aldol-lactonization reaction and the formation of a variety of 7-hydroxy-6H-benzo[c]chromen-6-ones. The hydroxy group was functionalized by using Suzuki
1,3-双甲硅烷基烯醇醚与苯并吡啶三氟甲磺酸酯的缩合反应是通过色酮与Me3SiOTf的反应原位生成的,提供了官能化的2,3-二氢苯并吡喃。用NEt 3或BBr 3处理后者会导致多米诺骨牌的迈克尔-迈克尔-醛缩内酰胺化反应,并形成多种7-羟基-6H-苯并[c] chromen-6-。通过使用Suzuki交叉偶联反应使羟基官能化。报道的方法学被应用于天然产物秋天水芹酚和一种新的荧光染料的合成,该荧光染料显示出有希望的光学性质。通过将色酮与包含一个偏氯基团的1,3-双甲硅烷基烯醇醚缩合,多米诺复古迈克尔-醛醇内酯化和苯甲酸酯化反应制得2,3-二氢-1H-4,6-二氧杂环戊烯-5-酮分子内威廉姆森反应。