General Reductive Heck Reaction- Now in Press

Our paper describing a reductive Heck hydroarylation reaction that is compatible with a variety of terminal and internal alkenes was accepted for publication today in ACS Catal. (click here). To bring this reaction to fruition we employ a high ligand-to-Pd(0) ratio to maintain coordinative saturation around the metal and prevent beta-hydride elimination. We originally focused the study exclusively on terminal alkenes but discovered that the reaction is actually reasonably efficient with cyclic internal alkenes during the peer review, so thanks to the referees for suggesting those experiments! (Acyclic internals are still a work in progress.) One of the most notable attributes of the reaction is that is extremely simple to set up, as it uses reagents that are commonly available in any organic chemistry lab and can be performed without exclusion of air or moisture. As a bonus, it tolerates a variety of Lewis basic functional groups, including pyridine heterocycles. Hats off to John who was the mastermind behind this project and performed 100% of the experiments in the final publication. As a reminder, a pre-print of this work was published on ChemRxiv back in June (click here).

Reductive Heck

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Zhen wins Lesly Starr Shelton Award

Congratulations to G4 student Zhen Liu who has been selected as the recipient of the 2017–2018 Lesly Starr Shelton Award for Excellence in Chemistry Graduate Studies. Way to go, Zhen!

About the award: Lesly Starr Shelton was a generous benefactor who has provided in her estate for an endowed scholarship in the chemistry graduate program at Scripps Research. Ms. Shelton has supported a student through this award since 1997, and was deeply interested in encouraging students in the sciences throughout her life.

Catalytic Cleavage of Strong Covalent Bonds via beta-X Elimination

In a paper appearing today online in Nat. Chem., the Engle lab reports a method of cleaving typically unreactive carbon–carbon and carbon–heteroatom bonds via β-X elimination from alkylpalladium(II) intermediates. This reaction enables functional group metathesis (or exchange) between C(sp3)–C, C(sp3)–N, C(sp3)–O, and C(sp3)–S, and C(sp3)–F bonds, which has enabled the development of synthetically useful new transformations, such as the upgrading of inexpensive natural amino acids to valuable non-natural counterparts. Congrats to the project team of Van, John, and Kin on this awesome piece of work. Click here for a link.

beta-elimination

image1(not pictured: Kin)

Tim, Omar, and Nhi complete their internships

It is a bittersweet week, as the Engle lab bids farewell to three awesome summer interns: Tim Gallagher (Claremont McKenna), Omar Apolinar (CSU San Marcos), and Nhi Nguyen (San Marcos High School). All three made huge contributions to their respective projects, and we will miss them all dearly. Thanks to all three for their hard work throughout the summer, and props to Van, Mingyu, and Rei for being great mentors. We look forward to following Tim, Omar, and Nhi’s progress throughout their careers as they take the chemistry world by storm!

 

 

 

 

Engle Lab Organizes Inaugural Organometallics Bootcamp

Senior members of the Engle lab are organizing the inaugural “Organometallics Bootcamp” for incoming first-year grad students, undergraduates, and guests from other groups at TSRI and neighboring universities. The bootcamp meets mornings from 8–9 AM and select evenings, and it covers topics ranging from basic structure and bonding to state of the art cross-coupling methods. Contact keary(at)scripps.edu if you are interested in participating.