In addition to facilitating the identification of highly selective ligands, a diverse coverage of chemical space provides a platform to analyze correlations between descriptors and reaction outcomes. The molecular electrostatic potential minimum (V min ) in the phosphorus lone pair region is a quantitative measure of the σ-donating ability of a phosphine ligand, and was therefore chosen as a suitable electronic descriptor (Figure ). More specifically, Boltzmann-averaged V min values from the collection of ligand conformers in the kraken library were used (V min (Boltz)). Regarding steric effects, buried volume (V bur ) is defined as the total volume of a sphere that is occupied by the substituents of the ligand (in this case, the sphere is centered on the phosphorus atom with a radius of 3.5 Å). Furthermore, the minimum buried volume (V bur (min)) is the smallest possible value of V bur for energetically accessible conformers of the ligand. Hence, V bur (min) quantifies the lowest proximal steric bulk associated with a ligand and was recently applied as a readout of ligation state in Pd-and Ni-catalyzed crosscouplings. Visualization of the stereoelectronic space was performed by plotting the ligands using the two aforementioned descriptors and coloring the points by reaction output. A single productive region of ligand space was observed for high reactivity with V min (Boltz) values from -0.062 to -0.038 V and V bur (min) values from 42 to 50 Å 3 (Figure , orange box). Two distinct regions were apparent for either high (E)-or high (Z)selectivity (Figure , red and blue boxes), separated electronically at roughly -0.058 V, with electron deficient phosphines displaying greater (Z)-selectivity and vice versa. Regarding V bur (min), the two selectivity regions were separated at ~52 Å 3 , which is a value that generally distinguished between mono-and bis-ligated Ni-complexes in a recent study reported by Sigman and Doyle. However, further investigation would be required to confirm the influence of ligation state on selectivity in this transformation.