DYKAT of Baylis−Hillman Adducts: Concise Total Synthesis of Furaquinocin E

Baylis−Hillman adducts are easily accessible building blocks; the lack of asymmetric versions of the Baylis−Hillman reaction has however precluded their widespread use in asymmetric synthesis. A Pd-catalyzed DYKAT on carbonates derived from Baylis−Hillman adducts, followed by a reductive Heck reaction, allows the enantio- and diastereoselective construction of dihydrobenzofurans in a very efficient manner. These synthons represent the core structure of the furaquinocins. Introduction of different side chains and use of different squaric acid derivatives for the construction of the naphthoquinone allow the flexible synthesis of this class of natural products. This new approach is successfully applied to the synthesis of furaquinocin E and an analogue.

贝利斯-希尔曼加合物（Baylis−Hillman adducts）是一类易于获取的合成砌块；然而，由于贝利斯-希尔曼反应（Baylis−Hillman reaction）缺乏不对称变体，其在不对称合成中的广泛应用受到了阻碍。以贝利斯-希尔曼加合物衍生的碳酸酯为底物的钯催化动态动力学不对称转化（DYKAT），随后经还原Heck反应（reductive Heck reaction），可高效实现二氢苯并呋喃的对映选择性与非对映选择性构建。此类合成子（synthons）对应夫拉喹诺辛类（furaquinocins）的核心骨架。通过引入不同侧链，并利用不同方酸衍生物（squaric acid derivatives）构建萘醌（naphthoquinone）骨架，可灵活合成该类天然产物。该全新合成策略已成功应用于夫拉喹诺辛E及其类似物的合成。