Pulsed ultrasonic irradiation with on‐off modulation remarkably enhances asymmetric noncovalent organocatalysis "on water", specifically for Michael addition and Diels‐Alder reactions. This approach effectively addresses challenges associated with solid reactant dispersion encountered in "on‐water" reactions and mitigates overheating issues caused by continuous ultrasound exposure, thereby significantly augmenting reaction rates and stereoselectivities.

中文翻译：

---

开关脉冲超声促进“水上”不对称非共价有机催化：迈克尔加成和第尔斯-阿尔德反应的研究

具有开关调制的脉冲超声波辐射显着增强了“水上”不对称非共价有机催化，特别是迈克尔加成和狄尔斯-阿尔德反应。这种方法有效地解决了“水上”反应中遇到的固体反应物分散相关的挑战，并减轻了连续超声暴露引起的过热问题，从而显着提高了反应速率和立体选择性。