Following Nature’s Lead. Designing a Very Simple yet Effective Ligand System Applicable to Pd-Catalyzed Cross Couplings…in Water

A new ligand design based on Nature’s use of simple elements is described. This relatively uncommon array of atoms is arrived at in a single step leading to “P3N” ligands, such as “(n-Bu2N)3P”, derived from PCl3 and three equivalents of n-Bu2NH. These readily participate in homogeneous, Pd-catalyzed Cu-free Sonogashira and Suzuki-Miyaura couplings. Reliance on low loadings of Pd is documented under aqueous micellar conditions (i.e., in water). Comparisons with several typically used representative ligands, which, by contrast are made in an environmentally egregious fashion, clearly show that this new series of ligands is preferred, cost-wise, synthetically, as well as in terms of their environmental impact.