Visible‐Light‐Driven Intermolecular Reductive Ene–Yne Coupling by Iridium/Cobalt Dual Catalysis for C(sp
<sup>3</sup>
)−C(sp
<sup>2</sup>
) Bond Formation
作者:María J. González、Bernhard Breit
DOI:10.1002/chem.201903708
日期:2019.12.10
A new methodology to form C(sp3 )-C(sp2 ) bonds by visible-light-driven intermolecular reductive ene-yne coupling has been successfully developed. The process relies on the ability of the Hantzsch ester to contribute in both SET and HAT processes through a unified cobalt and iridium catalytic system. This procedure avoids the use of stoichiometric amounts of reducing metallic reagents, which is translated
[2 + 2 + 1] Cycloaddition between Alkynes, Acrylates, and Titanocene(II): Regioselective Formation of 5-Alkoxycarbonyltitanacyclopent-2-enes and Their Addition to Carbonyls
5-Alkoxycarbonyltitanacyclopent-2-enes were produced regioselectively by the [2 + 2 + 1] cycloaddition between alkynes, acrylates, and titanocene(II) reagent Cp 2 Ti[P(OEt) 3 ] 2 . Although the titanacycles were inactive toward carbonyl compounds, their addition proceeded in the presence of titanocene(II).
通过炔烃、丙烯酸酯和二茂钛 (II) 试剂 Cp 2 Ti[P(OEt) 3 ] 2 之间的 [2 + 2 + 1] 环加成反应,区域选择性地制备了 5-烷氧基羰基钛环戊-2-烯。尽管钛环对羰基化合物无活性,但它们的加成是在二茂钛 (II) 存在下进行的。