Université de Strasbourg , CNRS, Laboratoire d'Innovation Thérapeutique, LIT UMR 7200 , 67000 Strasbourg , France.
Normandie Université , INSA Rouen, CNRS, COBRA UMR 6014 , 76000 Rouen , France.
J Org Chem. 2018 Apr 20;83(8):4505-4515. doi: 10.1021/acs.joc.8b00213. Epub 2018 Apr 6.
The stereocontrolled synthesis of unprecedented sulfur-containing exo-bicyclic 1,3-dienes is reported through a palladium-catalyzed reductive cyclization of sulfur-linked 2-bromoenynes. The fused bicyclic structure provides a better stability to the thiacyclic diene compared to the simple 3,4-dimethylenetetrahydrothiophene. Their reactivity toward several dienophiles has been investigated, and various original thiacycle-fused polycyclic systems have been obtained with high or total diastereoselectivity. Moreover, they are the first exo-bicyclic dienes used in Diels-Alder reactions. The relative configurations of four cycloadducts have been unambiguously assigned by X-ray crystallographic analysis. Mechanistic details of the cycloadditions have been examined by computational means.
通过钯催化硫连接的 2-溴烯炔的还原环化反应，报告了前所未有的含硫外双环 1,3-二烯的立体控制合成。与简单的 3,4-亚甲基四氢噻吩相比，稠合双环结构为硫杂环二烯提供了更好的稳定性。它们对几种亲二烯体的反应性已经进行了研究，并通过高或完全非对映选择性获得了各种原始的硫杂环稠合多环体系。此外，它们是首次用于 Diels-Alder 反应的外双环二烯。通过 X 射线晶体学分析明确指定了四个环加成物的相对构型。通过计算手段检查了环加成的反应机理细节。
