Synthesis and Characterization of Chiral Porphyrin Derived from (–)‐α‐Phellandrene

Abstract The bicyclo[2.2.2]octadiene (BCOD) skeleton‐fused chiral pyrrole 3a was successfully prepared by Diels–Alder reaction of (–)‐α‐phellandrene and disulfonyl ethylene, and seed‐crystal precipitation method. The following InCl 3 ‐catalyzed tetrameric cyclization and subsequent dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) oxidation afforded the chiral porphyrin like a unidirectionally oriented wind turbine without scrambling. The free‐base form and its Zn‐, and Pt complexes ( 4‐H 2 , 4‐Zn , and 4‐Pt ) were characterized by NMR spectra, absorption and emission spectra. Their chiral characters were investigated by circular dichroism (CD) spectra and their solid‐state structures were determined by means of X‐ray diffraction analysis. The retro Diels–Alder reaction of this chiral BCOD‐fused porphyrin was performed at 200 °C, yielding the resulting π‐conjugation expanded tetramethyltetrabenzoporphyrin quantitatively.