This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record.

Axially chiral styrene‐carboxylic esters were synthesized in high yields with excellent enantioselectivity by the cationic rhodium(I)/H8‐BINAP complex‐catalyzed chelation‐controlled [2+2+2] cycloaddition reactions of 1,6‐ and 1,7‐diynes with 1,3‐enyne‐carboxylic esters. The diastereo‐ and enantioselective synthesis of C2 symmetric axially chiral cis and trans‐stilbene‐dicarboxylic esters was also achieved by the double [2+2+2] cycloaddition reactions of two molecules of the 1,6‐diyne with 2,3‐dialkynylmaleate and 2,3‐dialkynylfumarate, respectively. In these reactions, the 1,3‐enyne‐carboxylic esters coordinating to rhodium with a five‐membered chelate were more reactive than those coordinating to rhodium with a six‐membered chelate, although both chelation modes realized excellent enantioselectivity. The enantioselection mechanism of the cationic rhodium(I)‐catalyzed chelation‐controlled [2+2+2] cycloaddition was elucidated by DFT calculations.

The lateral π-extension of helicenes would yield interesting physical properties derived from the enhanced π-stacking ability as well as intrinsic helical chirality. Here we report the regiodivergent synthesis of hexabenzocoronene (HBC)-based [6]helicenes via cationic rhodium(I)/segphos complex-mediated intramolecular [2 + 2 + 2] and [2 + 1 + 2 + 1] cycloadditions of triynes followed by Scholl reaction. The resulting HBC-based[6]helicenes possess stable helical chirality but more planar structure than previously reported HBC-based [7] and [9]helicenes. Therefore, these HBC-based [6]helicenes exhibit πstacking-induced chiral self-recognition in solution, allowing the measurement of enantiomeric ratios by 1 H NMR spectroscopy without any chiral additive.

This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record.