Palladium‐Catalyzed <i>S</i>‐Allylation of Vinyl Carbinols – Total Syntheses of Carotenoids by Julia‐Kocienski Olefination
作者:Aleksei N. Golikov、Chibeom Seo、Jae Hwan Lee、Sangho Koo
DOI:10.1002/adsc.202301055
日期:2024.1.9
Palladium catalyzed S-allylation of vinyl carbinols from ionones (or conjugated carbonyls) with 2-mercapto-1,3-benzothiazole (BT-SH) provides versatile C15 dienyl benzothiazolyl (BT) sulfides. This Pd(dppe)Cl2-catalyzed S-allylation is highly selective for free allylic alcohols in the presence of allylic acetates, resulting in 3- or 4-acetoxy C15 dienyl BT-sulfides suitable for xanthophyll synthesis
钯催化紫罗兰酮(或共轭羰基)与 2-巯基-1,3-苯并噻唑 (BT-SH) 发生乙烯基甲醇的 S-烯丙基化反应,得到多用途的 C 15二烯基苯并噻唑基 (BT) 硫化物。这种Pd(dppe)Cl 2催化的S-烯丙基化在烯丙乙酸酯存在下对游离烯丙醇具有高度选择性,产生适合叶黄素合成的3-或4-乙酰氧基C 15二烯基BT-硫化物。相应的C 15二烯基BT-砜与C 10 2,7-二甲基-2,4,6-辛三烯二醛在温和条件下进行Julia-Kocienski烯化反应,生成类胡萝卜素天然产物。实现了一系列类胡萝卜素的高效合成,包括叶黄素(如异玉米黄质、玉米黄质和叶黄素)以及胡萝卜素(如 β-胡萝卜素、ε-胡萝卜素和 9'- Z-苯基胡萝卜素)。