Fig. 5: Molecular force probe ligands and associated changes in enantioselectivity.
From: Strain-dependent enantioselectivity in mechanochemically coupled catalytic hydrogenation
a, Schematic representation of the compression (left) and extension (right) of a bisphosphine ligand in Z(m,n) and E(m,n) macrocycles. b, Measured e.r. of hydrogenation as a function of the calculated force across the phenoxyl atoms for substrates 1 and 3–5. Error bars represent 1 s.d.; data are shown as mean ± s.d., with n = 3 biologically independent replicates per condition. Each replicate corresponds to a separately prepared batch of polymer support. 2-Naphth, 2-naphthalene. c, Calculated e.r. of reaction (1) at nine values of tensile force applied across the MeOC⋯COMe coordinate of the biphenyl ligand of the catalyst/substrate complex at the MN15/def2TZVP level of density functional theory in vacuum; the values were derived by numerical kinetic modelling assuming irreversible traversal of TS2 (Fig. 2). We confirmed that the constituent elementary steps of the reaction mechanism do not change at forces of 0.5 nN and 2.0 nN (Supplementary Fig. 3). Lines connecting the circles are for guiding only. Source data are available from figshare60.
