Iridium‐Catalyzed C(
<i>sp</i>
<sup>3</sup>
)−H Addition of Methyl Ethers across Intramolecular Carbon–Carbon Double Bonds Giving 2,3‐Dihydrobenzofurans
作者:Toshimichi Ohmura、Satoshi Kusaka、Takeru Torigoe、Michinori Suginome
DOI:10.1002/adsc.201900749
日期:2019.10.8
Intramolecular addition of an O‐methyl C(sp3)−H bond across a carbon‐carbon double bond occurs in the iridium‐catalyzed reaction of methyl 2‐(propen‐2‐yl)phenyl ethers. The Ir/(S)‐DTBM‐SEGPHOS catalyst promotes the reaction efficiently in toluene at 110–135 °C to afford 3,3‐dimethyl‐2,3‐dihydrobenzofurans. Enantioselective C(sp3)−H addition is achieved in the reaction of methyl 2‐(1‐siloxyethenyl)phenyl
跨碳-碳双键的O-甲基C(sp 3)-H键的分子内加成发生在铱催化的甲基2-(丙烯-2-基)苯基醚的反应中。Ir /(S)-DTBM-SEGPHOS催化剂可在110-135°C的甲苯中有效地促进反应,得到3,3-二甲基-2-3,二氢苯并呋喃。对映选择性的C(sp 3)-H加成反应是通过甲基2-(1-甲硅烷氧基乙烯基)苯基醚的反应实现的,从而提供了对映体富集的3-羟基-2,3-二氢苯并呋喃衍生物,其ee高达96%。