Stepwise Chemical Reduction of [4]Cyclo[4]helicenylene: Stereo Transformation and Site-Selective Metal Complexation.

ABSTRACT: A highly strained macrocycle comprising four [4]helicene panels, [4]cyclo[4]helicenylene ([4]CH, 1), was synthesized through a one-pot macrocyclization and chemically reduced by alkali metals (Na and K), revealing a four-electron reduction process. The resulting di-, tri-, and tetraanions of compound 1 were isolated and crystallographically characterized by X-ray diffraction. Owing to the four axially chiral bi[4]helicenyl fragments, a reversible stereo transformation of 1 between the (S,R,S,R)- and (S,S,R,R)-configurations was disclosed upon the two-electron uptake, which was rationally understood by theoretical calculations. The (S,S,R,R)-configuration of 1 ^2- was fu

SUBMITTER: Zhou Z 

PROVIDER: S-EPMC11775854 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature