Overcrowded Triply Fused Carbo[7]helicene

This
paper presents the synthesis and comprehensive analysis of
a highly contorted and doubly negatively curved multihelicene compound,
composed of three carbo[7]helicene units fused within a central six-membered
ring. The synthesis of this compound involved a [2 + 2 + 2] cycloaddition
reaction of 13,14-picyne, employing a Ni(0) catalyst, which exhibited
superior performance compared to conventional Pd(0) catalysts. The
evaluation of aromaticity in this triple carbo[7]helicene, utilizing
magnetic and electronic criteria, led to noteworthy insights challenging
the limitations of Clar’s model of aromaticity.