Catalytic Asymmetric [8+2] Annulation Reactions Promoted by a Recyclable Immobilized Isothiourea
作者:Shoulei Wang、Carles Rodríguez-Escrich、Miquel A. Pericàs
DOI:10.1002/anie.201707341
日期:2017.11.20
enriched cycloheptatrienes fused to a pyrrolidone ring on the basis of an isothiourea‐catalyzed periselective [8+2] cycloaddition reaction between chiral ammonium enolates (generated in situ from carboxylic acids) and azaheptafulvenes. The resulting bicyclic compounds can be hydrogenated, but, most remarkably, they can also undergo completely regioselective [4+2] cycloaddition with active dienophiles to
高阶环加成反应是构建中大型环系统的有效方法。但是,这些转化的对映选择性形式仍然很少,这阻碍了它们在药物化学或任何其他认为同手性至关重要的学科中的应用。在这里,我们报道了一种新的方法,用于生产手性烯醇铵烯醇铵(由羧酸原位生成)和氮杂七富烯之间的异硫脲催化的超选择性[8 + 2]环选择性加成反应,该方法与吡咯烷酮环稠合,生成对映异构体富集的环庚烯。可以将所得的双环化合物氢化,但最显着的是,