Gold(I)-catalyzed annulation of salicylaldehydes and aryl acetylenes as an expedient route to isoflavanones
Gold(I)-catalyzed annulation of salicylaldehydes and aryl acetylenes as an expedient route to isoflavanones
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DOI：
10.1002/anie.200603495
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发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Li, Chao-Jun
中科院分区：
文献类型：
--
作者：
Skouta, Rachid;Li, Chao-Jun
异黄烷酮广泛存在于自然界中；异黄烷酮部分是许多复杂天然产物的关键结构特征，例如紫檀类化合物和圣毛菌素 B（方案 1）。[1]合成异黄酮的经典方法是 1) 使用复合金属氢化物还原烷氧基异黄酮；[2, 3] 2) 3-苯基香豆素或 4-羟基-3-苯基香豆素硼氢化，然后用铬酸氧化；[4] 3) 4-酰氧基 2H-色烯用 Heck 芳基化 芳基汞 (ii) 化合物在催化量的乙酸钯存在下；[5] 4) 用二碘甲烷处理 2-羟基烷氧基脱氧苯甲酸；[4] 和 5) 在仲胺（如哌啶或 二甲胺，在沸腾的甲醇中。[6]然而，这些方法受到使用昂贵的起始材料以及在某些情况下有毒试剂的限制。[5]金催化最近已成为合成中的强大工具。[7, 8]例如，杂双环分子、[9]高度取代的吡咯、[10]呋喃、[11]和苯并二氢吡喃醇[12]已通过金基催化方便地合成。金催化反应也被用作安古环酮抗生素全合成的关键步骤。 [13]我们有
Isoflavanones are widely present in nature; the isoflavanone moiety is the key structural feature of many complex natural products, such as the pterocarpenoids and eriotrichinB (Scheme 1).[1] The classical methods for synthesizing isoflavanones are 1) the reduction of alkoxy isoflavones by using a complex metal hydride;[2, 3] 2) the hydroboration of 3-phenylcoumarin or 4-hydroxy-3-phenylcoumarin followed by oxidation with chromic acid;[4] 3) Heck arylation of 4-acyloxy 2H-chromenes with aryl mercury (ii) compounds in the presence of catalytic amounts of palladium acetate;[5] 4) the treatment of 2-hydroxyalkoxy deoxybenzoines with methylene iodide;[4] and 5) the Mannich reaction of 2-hydroxyalkoxy deoxybenzoines with paraformaldehyde in the presence of secondary amines, such as piperidine or dimethylamine, in boiling methanol.[6] However, these methods are limited by the use of expensive starting materials and, in some cases, toxic reagents.[5]Gold catalysis has emerged recently as a powerful tool in synthesis.[7, 8] For example, heterobicyclic molecules,[9] highly substituted pyrroles,[10] furans,[11] and chromanols [12] have been synthesized expediently by gold-based catalysis. A gold-catalyzed reaction has also been used as a key step in the total synthesis of angucyclinone antibiotics.[13] We have