Origin of the Preferential Formation of Helicenes in Mallory Photocyclizations. Temperature as a Tool to Influence Reaction Regiochemistry
作者:J. Weber、E. L. Clennan
DOI:10.1021/acs.joc.8b02671
日期:2019.1.18
bis-Mallory photocyclization substrates has been examined from experimental and computational perspectives. Formation of all three possible regioisomers was only observed in the reaction of one of the substrates. In the other three substrates, only the two C2-symmetric products, but not the C1 product, were formed. In the three reactions that only formed two products, the photocyclization temperature
developed to construct PAHs with diverse shape, width, and edge topology. The precursors of PAHs were obtained by using a direct arylation of arenes via a transient ligand-directed C–H functionalization strategy and the cycloaromatization was readily achieved by using a Brønstedacid catalyst. This novel route provides an opportunity to build up PAHs in a highly efficient manner.