Highly Efficient Synthesis of C3-symmetry O-alkyl Substituted Triphenylene and Related Mannich Derivatives

C3-symmetric tris-benzyl-O-substituted hexahydroxytriphenylene (HHTP) was prepared through selective ring opening with DIBAL-H in 48% yield (38% from HHTP in a two step synthesis) avoiding the use of noxious, expensive and with limited market availability reagents, with complete recovery of the undesired Cs co-product that is quantitatively recovered and converted back to HHTP. The C3-symmetric triphenylene product was further functionalized through substitution, deprotection and Mannich condensation reactions affording a series of C3-symmetric functionalized scaffolds in good yields for supramolecular applications