Fig. 3: Investigation of track composition for controlled directional motion of Rh centre.
From: [1,n]-Metal migrations for directional translational motion at the molecular level
a Library of electronically differentiated biaryl tracks as substrates under optimised reaction conditions: biaryl 1–8 (0.20 mmol), norbornene (11 equiv.), [RhCl(cod)]2 (5.0 mol%), dppp (10 mol%), CsF (2.0 equiv.), 1,4-dioxane:IPA (98:2), 80 °C, 16 h; a [RhCl(cod)]2 (2.5 mol%), dppp (5.0 mol%); b Hammett σ values are given relative to position 6, i.e., Entries 1–3, 5: σm, Entry 4: σp; c combined 1H NMR spectroscopy yield of di- and tri-substituted products using 1,3,5-trimethoxybenzene as an internal standard; d isolated yield of tri-substituted product in parentheses; e isolated yield of tetra-substituted product; f ratio of substitution products di: tri determined by 1H NMR spectroscopy of crude reactions. b Directly linked polyphenylene track with bent conformation, 9, under optimised reaction conditions with [RhCl(cod)]2 (5.0 mol%), dppp (10 mol%) giving penta-9; isolated yield. c Methylene-linked biaryl tracks (10–12) as substrates under optimised reaction conditions with [RhCl(cod)]2 (2.5 mol%), dppp (5.0 mol%) giving poly-substituted tracks tri-10, tetra-11, tetra-12; isolated yields. d Me2Si– (13), MeN– (14), and O– (15) linked biaryl tracks as substrates under optimised reaction conditions with [RhCl(cod)]2 (2.5 mol%), dppp (5.0 mol%) giving tri-substituted tracks tri-13, tri-14, tri-15; isolated yields. Note that all incorporated norbornane units are depicted arbitrarily as (R,R,S).
