Highly Efficient Conversion of Propargylic Alcohols and Propargylic Amines with CO<sub>2</sub> Activated by Noble‐Metal‐Free Catalyst Cu<sub>2</sub>O@ZIF‐8
Ai‐Ling Gu, Ya‐Xin Zhang, Zhi‐Lei Wu, Hui‐Ya Cui, Tian‐Ding Hu, Bin Zhao
Abstract
Abstract The cyclization reactions of propargylic alcohols and propargylic amines with CO 2 are important in industrial applications, but it was a great challenge that non‐noble‐metal catalysts catalyzed both reactions under mild conditions. Herein, the catalyst Cu 2 O@ZIF‐8 was prepared by encapsulating Cu 2 O nanoparticles into robust ZIF‐8, and it can effectively catalyze the cyclization of both propargylic alcohols and propargylic amines with CO 2 into valuable α‐alkylidene cyclic carbonates and oxazolidinones with turnover numbers (TONs) of 12.1 and 19.6, which can be recycled at least five times. The mechanisms were further uncovered by NMR, FTIR, 13 C isotope‐labeling experiments and DFT calculations, in which Cu 2 O and DBU can synergistically activate the C≡C bond and the hydroxy/amino group of substrates. Importantly, it is the first example of a noble‐metal‐free catalyst that can catalyze both propargylic alcohols and propargylic amines with CO 2 simultaneously.