Enantioselective Inverse Electron Demand (3 + 2) Cycloaddition of Palladium-Oxyallyl Enabled by a Hydrogen-Bond-Donating Ligand
作者:Yin Zheng、Tianzhu Qin、Weiwei Zi
DOI:10.1021/jacs.0c11504
日期:2021.1.20
Cycloaddition reactions between oxyallyl cations and alkenes are important transformations for the construction of ring systems. Although (4 + 3) cycloaddition reactions of oxyallyl cations are well-developed, (3 + 2) cycloadditions remain rare, and an asymmetric version has not yet been developed. Moreover, because oxyallyl cations are highly electrophilic, only electron-rich olefins can be used as
氧烯丙基阳离子和烯烃之间的环加成反应是构建环系的重要转化。尽管氧烯丙基阳离子的 (4 + 3) 环加成反应很发达,但 (3 + 2) 环加成反应仍然很少,并且尚未开发出不对称版本。此外,由于氧烯丙基阳离子具有高度亲电性,因此只有富电子烯烃才能用作环加成伙伴。我们在此报告了一种钯-氧烯丙基物种与缺电子硝基烯烃之间的对映选择性 (3 + 2) 环加成反应的方法。这种转变是通过合理设计的氢键供体配体(FeUrPhos)实现的,并通过逆电子需求途径进行。使用这种方法,