Photoinduced inverse Sonogashira coupling reaction

• Published in: Chemical science (Cambridge) Vol. 13; no. 25; pp. 7475 - 7481
• Main Authors: Zhang, Lizhu, Wei, Cunbo, Wu, Jiawen, Liu, Dan, Yao, Yinchao, Chen, Zhuo, Liu, Jianxun, Yao, Chang-Jiang, Li, Dinghua, Yang, Rongjie, Xia, Zhonghua
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 29.06.2022; Royal Society of Chemistry; The Royal Society of Chemistry
• Subjects: Alkenes; Alkynes; Aromatic compounds; Chemistry; Chemistry, Multidisciplinary; Coupling; Light irradiation; Materials science; Physical Sciences; Science & Technology; Transition metals; SUBSTITUTION; BOND-DISSOCIATION ENERGIES; HOMOLYSIS; CHEMISTRY; RADICALS; DERIVATIVES; C-H ALKYNYLATION; CARBOXYLIC-ACIDS; DECARBOXYLATIVE ALKYNYLATION; PHOTOREDOX CATALYSIS
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d2sc01933g

Alkynes are widely used in chemistry, medicine and materials science. Here we demonstrate a transition-metal and photocatalyst-free inverse Sonogashira coupling reaction between iodoalkynes and (hetero)arenes or alkenes under visible-light irradiation. Mechanistic and computational studies suggest that iodoalkynes can be directly activated by visible light irradiation, and an excited state iodoalkyne acted as an "alkynyl radical synthetic equivalent", reacting with a series of C(sp 2 )-H bonds for coupling products. This work should open new windows in radical chemistry and alkynylation method. A transition-metal and photocatalyst-free, photoinduced inverse Sonogashira coupling reaction was developed. Under visible-light irradiation, the excited state iodoalkyne acted as an "alkynyl radical synthetic equivalent".