Medicinal Chemistry Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu-180001, India.
Org Biomol Chem. 2012 Jul 14;10(26):5143-50. doi: 10.1039/c2ob25376c. Epub 2012 May 30.
An efficient one-pot multi-component synthesis of flavans using perchloric acid supported on silica as a recyclable heterogeneous catalyst has been described. This is the first report of direct one-step construction of a flavan skeleton from a phenolic precursor. The method involves a Knoevenagel-type condensation leading to in situ formation of transient O-quinone methide which further undergoes [4 + 2]-Diels-Alder cycloaddition with styrene to yield a flavan skeleton. The method provides easy access to a wide range of bio-active natural products viz. flavonoids, anthocyanins and catechins.
已描述了使用负载在二氧化硅上的高氯酸作为可回收的多相催化剂，高效一锅法多组分合成黄烷的方法。这是首次报道从酚前体直接一步构建黄烷骨架。该方法涉及 Knoevenagel 型缩合，导致瞬态 O-醌亚甲基的原位形成，其进一步与苯乙烯进行[4 + 2]-Diels-Alder 环加成，生成黄烷骨架。该方法可方便地获得广泛的生物活性天然产物，例如黄酮类化合物、花青素和儿茶素。
