School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Org Biomol Chem. 2020 May 6;18(17):3258-3262. doi: 10.1039/d0ob00480d.
Although the 2-position-selective decarboxylative coupling or addition of arylpropiolic acids with cyclic ethers has been intensively investigated, selective functionalization of arylpropiolic acids at the 3-position is still a big challenge. Herein, an intriguing and mild method for visible light induced regioselective addition of arylpropiolic acids by attacking exclusively at the 3-position with cyclic/acyclic ethers was developed. A variety of 3,3-bis-substituted acrylic acids were successfully obtained in moderate to excellent yields. A plausible reaction mechanism involving an energy transfer induced radical addition in the presence of visible light and photocatalyst was proposed.
虽然 2-位选择性脱羧偶联或芳基丙炔酸与环醚的加成已经得到了深入研究，但芳基丙炔酸在 3-位的选择性官能化仍然是一个巨大的挑战。在此，本文开发了一种有趣且温和的可见光诱导方法，通过与环状/非环状醚进行专一地 3-位加成，实现芳基丙炔酸的区域选择性加成。在可见光和光催化剂的存在下，通过能量转移诱导自由基加成，成功地获得了各种 3,3-双取代丙烯酸，产率中等至优秀。提出了一个合理的反应机理。
