Parida Keshaba N, Pathe Gulab K, Maksymenko Shimon, Szpilman Alex M
Department of Chemical Sciences, Ariel University, 4070000 Ariel, Israel.
Beilstein J Org Chem. 2018 May 3;14:992-997. doi: 10.3762/bjoc.14.84. eCollection 2018.
Due to their closely matched reactivity, the coupling of two dissimilar ketone enolates to form a 1,4-diketone remains a challenge in organic synthesis. We herein report that umpolung of a ketone trimethylsilyl enol ether (1 equiv) to form a discrete enolonium species, followed by addition of as little as 1.2-1.4 equivalents of a second trimethylsilyl enol ether, provides an attractive solution to this problem. A wide array of enolates may be used to form the 1,4-diketone products in 38 to 74% yield. Due to the use of two TMS enol ethers as precursors, an optimization of the cross-coupling should include investigating the order of addition.
由于两种不同酮烯醇盐的反应活性相近，因此在有机合成中，将它们偶联形成1,4 - 二酮仍然是一项挑战。我们在此报告，将酮三甲基硅基烯醇醚（1当量）进行极性翻转以形成离散的烯鎓物种，随后加入低至1.2 - 1.4当量的第二种三甲基硅基烯醇醚，为这个问题提供了一个有吸引力的解决方案。可以使用多种烯醇盐以38%至74%的产率形成1,4 - 二酮产物。由于使用两种三甲基硅基烯醇醚作为前体，交叉偶联的优化应包括研究添加顺序。
