Towards an Effective Synthesis of Difunctionalized Heptacyclo [6.6.0.02,6.03,13.04,11.05,9.010,14]tetradecane: Ligand Effects on the Cage Assembly and Selective C-H Arylation Reactions

A series of strong it-acceptor polyfluorinated and dicationic chelating phosphines have been synthesized and evaluated in the Rh-catalysed dimerization of norbornadiene (NBD) into its thermodynami- cally . more stable dimer, heptacyclo[6.6.0.0(2,6).0(3,13).0(4,11).0(5,9).0(10,14)] tetradecane (HCTD). While dicationic ligands direct the dimerization towards HCTD, by the use of neutral polyfluorinated ancillary ligands endo-endoheptacyclo [8.4.0.0(2,12).0(3,8).0(4,6).0(5,9).0(11,13)]tetradecane (BINOR-S) is selectively obtained. In addition, a selective Pd-catalysed arylation at position C8 of the HCTD framework is achieved by the use of a picolylamide directing group previously attached at C1. Theoretical calculations have been performed to understand the origin of that regioselectivity.

Automated summary

A series of strong it-acceptor polyfluorinated and dicationic chelating phosphines were synthesized and evaluated in the Rh-catalysed dimerization of norbornadiene, leading to the selective formation of specific products and site-selective arylation reactions. Theoretical calculations were performed to understand the origin of the observed regioselectivity.