Surfactant Technology: With New Rules, Designing New Sequences Is Required!

With a growing toolbox of surfactant-mediated chemistry in water and an increased number of scaled-up transformations has come tremendous learning [for example, see: Lipshutz, B. H.; et al. The Hydrophobic Effect Applied to Organic Synthesis: Recent Synthetic Chemistry “in Water”. Chem.- Eur. J. 2018, 24 (26), 6672–6695]. These opportunities now reside within a few expert groups, and while all of the details are far from fully understood or still under development, substantial know-how has been gained in both reaction process and synthesis design. Herein we share some of the fundamental principles inherent to micellar catalysis and illustrate them on a particularly challenging case involving a Suzuki–Miyaura cross-coupling. The complete structures of the active pharmaceutical ingredient (API) and the intermediates are not fully disclosed for confidentiality reasons but can nevertheless serve as illustrative of the importance of factors that, unlike traditional chemistry in organic solvents, can be crucial to a successful outcome (e.g., lipophilicity). The API used as an example for this discussion bears significant commonality with a large number of other targets associated with the formation of a biphenyl array as well as the presence of an amide and products resulting from nucleophilic aromatic substitutions (S_NAr). Hence, we look to utilize these prior learnings and can now rapidly apply them to the design of optimal conditions for several other important transformations.