C=C Bond (Hetero)annulation Review – Now Online

Hui-Qi and Phillippa’s Feature Article reviewing recent advances in Pd-catalyzed (hetero)annulation of C=C bonds with ambiphilic aryl halides has just been accepted for publication and appears online today in Chem. Commun. The article summarizes exciting advances in this field during the past 15 years, and highlights outstanding challenges that once solved will push the utility of this chemistry to even greater heights. Well done, Hui-Qi and Phillippa, and thanks to the Chem. Commun. editors for the invitation!

For a link to the article, click here: https://pubs.rsc.org/en/content/articlelanding/2021/cc/d1cc02836g#!divAbstract

Cu(CAAC)-Catalyzed Alkyne Protoboration and -Silylation Paper – Now In Press

In a paper appearing today online in Angewandte Chemie International Edition, we show the unique selectivity of Cu(CAAC) (CAAC = cyclic(alkyl)(amino)carbene) catalyst in mediating boryl and silyl additions to terminal alkynes. Through careful ligand optimization, we show how high Markovnikov selectivity can be maintained across different alkyne substrates and boryl/silyl coupling partners. This collaborative project brought together chemists from three different institutions in America’s Finest City: the Grotjahn lab at San Diego State University, the Bertrand lab at UC San Diego, and the Engle Lab at Scripps Research. Well done to the entire project team!

For a link to the paper, click here: https://onlinelibrary.wiley.com/doi/10.1002/anie.202106107

The work first appeared in ChemRxiv back in April. Check out the pre-print here: https://chemrxiv.org/engage/chemrxiv/article-details/60c75776f96a0044cb288c84

Luke wins the 2021 IPMI Johnson Matthey Student Award

Congratulations to rising G4 student Luke Oxtoby who has been awarded the 2021 International Precious Metals Institute Johnson Matthey Student Award in recognition of his graduate research, where he has achieve the first successful examples of enantioselective Heck-type alkene additions using a transient directing group strategy. Luke will travel to the IPMI annual conference in Reno, Nevada, in October, where he will present his research at a special awards session.

Welcome Yilin!

We have a new undergraduate intern Yilin, from UCSB. She has explored nickel-catalysis in aqueous micellar conditions as an undergraduate research assistant in Prof. Lipshutz’s group, and now she will be expanding her experience in nicekl catalysis, joining the Team Nickel under the mentorship of Ziqi.

The Engle Lab Turns 6

Time flies when you’re having fun, living through a pandemic, or both! The Engle lab celebrated six wonderful years at Scripps with an afternoon at the beach in Del Mar, where we enjoyed surfing, frisbee, and BBQ. The event doubled as a welcome party for our two newest members, José and Yilin. After more than a year of virtual social events, it was a special treat to gather together and celebrate this milestone.

Cross-metathesis route to alkenyl AQ amides

Over the years we’ve experienced first-hand the frustrations of resorting to circuitous synthetic routes to access substituted alkenyl AQ amide substrates, which serve as cornerstones of AQ-directed alkene functionalization chemistry. To address this Hui-Qi, Zi-Qi, and Van teamed up to develop a concise and modular method using cross-metathesis with the Grubbs 2nd generation catalyst. Remarkably the catalyst is impervious to the AQ group, allowing direct coupling of terminal alkenyl AQ amides with a variety of terminal alkenes. In one case, we shorten a four-step sequence to a single high-yielding step. This paper is part of a special issue in Tetrahedron celebrating Prof. Guangbin Dong’s 2021 Tetrahedron Young Investigator Award. Well done team!

For a link to the paper, click here: https://www.sciencedirect.com/science/article/abs/pii/S0040402021005019

Welcome José!

We have a summer visiting gradudate student José González from Gulías group at CIQUS-USC, Spain. He has been working on enantioselective Pd-catalyzed C-H activation at Gulías group. In the Engle lab, he is turning his attention to Ni-catalysis, collaborating with Taeho.

Andrew Successfully Defends his Thesis and Departs for BCG

On a whirlwind of a day, Andrew successfully defended his thesis over Zoom, dropped by campus for his champagne toast, and then hit the road for the transcontinental drive back to his hometown of Philadelphia. Starting next week, Andrew will begin his career as a consultant at Boston Consulting Group. We’re so grateful for your many contributions to the lab and proud of your accomplishments, Andrew. Good luck on this next adventure!

Enantioselective 1,2-Arylfluorination of Alkenes using a Transient Directing Group Strategy – Paper Now in Press

The final version of our manuscript describing the palladium-catlayzed enantioselective 1,2-arylfluorination of alkenes using a transient directing group (TDG) strategy is online today in J. Am. Chem. Soc. In the study we apply Design of Experiments (DoE) to optimize this challenging three-component coupling of alkenes, arylboronic acids, and [F+] electrophiles, which helps to account for the complex interactions between variables in this system. We further elucidate the reaction mechanism using reaction progress kinetic analysis (RPKA). In terms of preparative applications, the method proceeds in high ee and d.r., allowing formation of full substituted C(sp3)–Ar and C(sp3)–F centers. The transformation is the first time that 1,2-difunctionalization has been achieved using a TDG approach and as such represents an important milestone for our lab and for the field. Hats off to Zhonglin, Luke, Mingyu, Zi-Qi, Van, and Yang!

For a link to the paper, click here: https://pubs.acs.org/doi/10.1021/jacs.1c03178

The work first appeared on ChemRxiv back in January. Check out the pre-print here: https://chemrxiv.org/articles/preprint/A_Transient_Directing_Group_Strategy_Enables_Enantioselective_Multicomponent_Organofluorine_Synthesis/13537283

Van departs for Gilead

With the lab fully vaccinated we were very happy to be able to give Dr. Van Tran a proper send off, including a Korean BBQ trip and a champagne toast. Best of luck in your next adventure as a process chemist at Gilead, Van! We miss you already.