C. J. L. Ong, H. Han, I. H. Z. Koa, G. W. Z. Goh, G. C. Y. Ng, S. Ito*
Org. Lett. 2026, 28, in press. DOI: 10.1021/acs.orglett.6c01898
Abstract: Direct C−H/C−H coupling represents an attractive strategy for efficient carbon−carbon bond formation; however, the selective activation of unactivated C−H bonds remains a significant challenge. Here we report a mechanochemical approach to intramolecular C(sp3)−H/C(sp2)−H coupling using a potassium/ferrocene system, enabling the rapid synthesis of acridine and anthracene frameworks from unactivated substrates within 30 min of ball milling. The results reveal a unique interplay between alkali metals and ferrocene and provides a new platform for C(sp3)−H/C(sp2)−H coupling.