Today we report a new strategy for alkene functionalization that can deliver two valuable products in a single step by partnering a mutually enabling oxidative difunctionalization and reductive difunctionalization, a process we term redox-paired alkene functionalization. In the reported reaction system, a single palladium(II) catalyst switches between Pd^IIX and Pd^IIAr forms during the catalytic cycle, each of which is active in the respective half-reactions. Specifically, the catalytic cycle achieves oxidative [3+2] annulation with 2-naphthols and reductive 1,2-diarylation with aryl iodides, expanding the scope and utility of both of these transformations. Congrats to all of the co-workers in this collaborative project: Hui-Qi, Tian (May), Shenghua, and Zhen; as well as Malkanthi, who performed computational studies under the joint guidance of Profs. Ken Houk (UCLA) and Peng Liu (Pittsburgh).

For a link to the pre-print in ChemRxiv, click here: https://chemrxiv.org/engage/chemrxiv/article-details/63ad635fff4651a6983afddf

This week, in collaboration with the group of Prof. Julien Vantourout of ICBMS Lyon, we report complementary methods for E– and Z-selective kinetic isomerization of terminal alkenes under nickel catalysis. The two protocols are operationally simple to perform, employ commercially available reagents, and tolerate numerous synthetically useful functional groups. Congrats to all of the co-authors: Camille, Anne, Shenghua, and Zi-Qi. The project was initiated during Camille’s stint as a visiting student in Lyon earlier this year and was then wrapped up over the past few weeks to close out 2022 on a high note.

For a link to the pre-print in ChemRxiv, click here: https://chemrxiv.org/engage/chemrxiv/article-details/63aa9d68a53ea689e3590038

The peer-reviewed version of our paper describing the synthesis and characterization of elusive post-β-C-elimination organopalladium complexes is online today in Organometallics. In this paper, we find that the combination of chelation stabilization from the 8-aminoquinoline directing auxiliary and strain-release from ring-opening of the nopol framework allows for facile β-C-elimination to yield a series of N,N,π-C palladacycle products. Congrats to Taeho, Rei, Anna, and Tanner from our group at Scripps; Yue from Prof. Peng Liu’s group at University of Pittsburgh; and Arnie, Jake, and Milan from the crystallography core at UCSD.

For a link to the manuscript in Organometallics, click here: https://pubs.acs.org/doi/10.1021/acs.organomet.2c00530

As a reminder, a pre-print describing this work appeared at the end of October: https://chemrxiv.org/engage/chemrxiv/article-details/635875afca86b8d57fc36848

As per tradition, we celebrated the end of the year in style with tasty food, a fun white elephant gift exchange, and great company. Johny stole the show fashion-wise with his llama-themed sweater, and the burrito blanket was the hottest gift of the lot. Wishing everyone a magical holiday seasons, and looking forward to another great year to come in 2023!

The final version of our manuscript describing the development of a toolkit of bench-stable Ni(0) precatalysts for diverse organic transformations is now in press in Angewandte Chemie. This toolkit enables reactions reliant on air-stable Ni(0) sources such as Ni(COD)₂ to be performed without an inert atmosphere glovebox using standard Schleck techniques, offering a path forward for commercial scale-up of such catalytic methods. This work was made possible through a large network of collaborators at Scripps Research, USCD, Cornell, and Bristol Myers Squibb.

For coverage of this work in C&E News, see: https://cen.acs.org/acs-news/acs-meeting-news/Nickel-tamed-reagent-toolkit/100/i11

For a link to the paper in Angewandte Chemie, click here: https://onlinelibrary.wiley.com/doi/10.1002/anie.202211794

As a reminder, a pre-print of this work was uploaded to ChemRxiv back in February: https://onlinelibrary.wiley.com/doi/10.1002/anie.202214153

Janine Abuyuan, a Master’s degree student at UCSD joins the group for an internship! At UCSD, Janine works in the group of Prof. Cliff Kubiak, and previously she completed her undergraduate degree at Barnard College, during which time she worked with Prof. Jack Norton at Columbia University. Welcome to the group, Janine!

During the past few years, numerous synthetic methods have been developed that take advantage of catalytic C–C bond cleavage via β-C elimination from an alkylmetal intermediate to furnish a new Pd^II(olefin)(R) (R = Alkyl, Aryl, etc.) species. Nevertheless, igorous characterization of said post-β-C-elimination organometallic species has proven elusive. In collaboration with the Liu group at the University of Pittsburgh and the X-ray crystallography facility at UCSD, we have successfully synthesized well-defined post-β-C-elimination organopalladium complexes, enabled by a combination of strain-release to provide thermodynamic driving force and chelation stabilization to suppress potential side reactions. The complexes were characterized by single-crystal X-ray diffraction, and the potential energy surface of the β-C elimination step and other relevant processes was computed using density functional theory. Congrats to Taeho, Rei, Anna, and Tanner from Scripps Research; Yue from Pitt; and Arnie, Jake, and Milan from UCSD.

For a link to the pre-print in ChemRxiv, click here: https://chemrxiv.org/engage/chemrxiv/article-details/635875afca86b8d57fc36848

What a treat seeing our artists go all out for the annual halloween pumpkin carving party and potluck! Kudos to everyone for making this event special! Also, we all decided to dress up like our fearless leader!

Our recent study describing the palladium(II)-catalyzed coupling of nitroalkanes and unactivated alkenes has been accepted and appears online today in ACS Catalysis. We describe how the combination of PdI₂ as catalyst and HFIP as solvent is uniquely effective in enabling this historically challenging coupling process. The method allows for simple readily accessible starting materials to be elaborated into densely functionalized nitroalkane products, which can then be further derivatized as desired. Teaming up with our computational collaborators from the Liu group at the University of Pittsburgh, we describe how the carbopalladation transition state is stabilized by a Na···I interaction and an H···I hydrogen bond with HFIP. Congrats to Amit, Por, Hui-Qi, and John from our group; and Turki and Binh from the Liu group on this study.

To read the peer-reviewed paper in ACS Catalysis, click here: https://pubs.acs.org/doi/10.1021/acscatal.2c04557

As a reminder, a pre-print describing this transformation first appeared in ChemRxiv back in February: https://chemrxiv.org/engage/chemrxiv/article-details/61f8af581fd27415ef2206d7

Today’s second paper from the group appears in the Journal of the American Chemical Society and describes the first enantioselective nickel-catalyzed 1,2-dicarbofunctionalization of unactivated alkenes involving a closed-shell pathway. Key to the success of the transformation is the combined use of a sterically bulky monodentate sulfonamide directing group and a chiral hemi-labile bioxazoline (Bn-biOx) ligand, which work together during enantiodetermining arylnickel migratory insertion. This was a massive undertaking that spanned three years and involved collaborators from Scripps (Omar, Taeho, Pranali, Camille, Joe, Brittany, Quynh, Emily, and Jason), University of Pittsburgh (Turki), and Bristol Myers Squibb (Steve). Congrats to everyone on a great team effort!

Click here for a link to the paper in J. Am. Chem. Soc.: https://pubs.acs.org/doi/10.1021/jacs.2c06636

As a reminder, an initial pre-print describing this work first appeared in ChemRxiv back in June: https://chemrxiv.org/engage/chemrxiv/article-details/62b40edc0bbbc1d407726e34