Rhodium(I)/Zn(OTf)
<sub>2</sub>
‐Catalyzed Asymmetric Ring Opening/Cyclopropanation of Oxabenzonorbornadienes with Phosphorus Ylides
作者:Tao Chen、Lifei Gan、Ran Wang、Yuhua Deng、Fangzhi Peng、Mark Lautens、Zhihui Shao
DOI:10.1002/anie.201909596
日期:2019.10.28
nucleophiles in asymmetric organometallic catalysis. Herein we describe the first rhodium-catalyzed asymmetric ring-opening reaction of P-ylides utilizing oxabicyclic alkenes as the electrophilic partner. Various P-ylides including ester-, ketone- and amide-style P-ylides are all applicable. This asymmetric reaction occurs through the cleavage of two bridgehead C-O bonds and the formation of two C-C bonds,
P-基团与过渡金属的强结合能力限制了稳定的P-基团在不对称有机金属催化中作为亲核试剂的利用。在本文中,我们描述了使用氧杂双环烯烃作为亲电子配体的第一个铑催化的P-内酯的不对称开环反应。包括酯,酮和酰胺型的P-基在内的各种P-基均适用。这种不对称反应是通过两个桥头CO键的断裂和两个CC键的形成而发生的,草酸苯并降冰片二烯被用作1,4-双亲电子试剂,从而以高收率和高对映选择性和完美的非对映选择性提供了苯并降二十碳烯的途径。本协议还构成稳定的P-ylide亲核试剂的第一个高对映选择性直接催化不对称环丙烷化反应。