Phosphoric Acid Catalyzed Aldehyde Addition to in Situ Generated o-Quinone Methides: An Enantio- and Diastereoselective Entry toward cis-3,4-Diaryl Dihydrocoumarins.
Phosphoric Acid Catalyzed Aldehyde Addition to in Situ Generated o-Quinone Methides: An Enantio- and Diastereoselective Entry toward cis-3,4-Diaryl Dihydrocoumarins.
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DOI：
10.1021/acs.orglett.8b01865
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发表时间：
2018-08
期刊：
影响因子：
5.2
通讯作者：
Matthias Spanka;C. Schneider
中科院分区：
文献类型：
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作者：
Matthias Spanka;C. Schneider
本文报道了以邻羟基二苯甲醇和芳基乙醛为原料，磷酸为催化剂，高立体选择性合成顺式-3，4-二芳基苯并二氢吡喃醇的方法。产物可以进一步操作成3，4-二氢香豆素、4 H-色烯和色满，具有良好的总产率和非常好的非对映体和对映体控制。该反应基于烯醇催化的概念，包括原位生成氢键键合的邻醌甲基化物及其与醛烯醇的[4 + 2]-环加成。
A highly stereoselective, phosphoric acid catalyzed synthesis of cis-3,4-diarylchromanols through reaction of o-hydroxybenzhydryl alcohols and aryl acetaldehydes is reported. The products can be further manipulated to 3,4-dihydrocoumarins, 4 H-chromenes, and chromanes with good overall yields and very good diastereo- and enantiocontrol. This reaction is based upon the concept of enol catalysis and comprises the in situ generation of hydrogen-bonded o-quinone methides and their formal [4 + 2]-cycloaddition with aldehyde enols.