Transition metal catalyzed cross-coupling has generated a vast number of critically important synthetic methodologies in the past 40 years. Today, it benefits fields as wide-ranging as natural product synthesis to materials chemistry. Recent advancements in ligand design has allowed for the use of more challenging substrates, as well as reducing the harsh conditions that were once needed. However, this added complexity of the ancillary ligand makes the standard protocol, one that involves adding excess ligand to a palladium precursor, undesirable. This has led to the development of a wide range of palladium precatalysts, complexes that have the optimal 1:1 palladium to ligand ratio inherently built in to their structure. Our lab has developed a new precatalyst scaffold based on a sterically bulky indenyl ligand, with the general formula of (1-tBu-Indenyl)Pd(Cl)L, where L can be either a phosphine or an N-Heterocyclic carbene (NHC). This scaffold generates the active mono-ligated LPd0 far faster than other precatalyst motifs, as well as limits the formation of deleterious PdI species. We have demonstrated the effectiveness of this scaffold in a multitude of cross-coupling reactions, including Suzuki-Miyaura, Buchwald-Hartwig and alpha-arylation. Furthermore, we have developed cross-coupling methodology with our precatalyst scaffold that allows for the use of exciting, challenging electrophiles and nucleophiles.

Rational design of improved Pd(II) precatalysts and their application towards new cross-coupling reactions

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.