Malkanthi receives 2021 Cottrell Postdoc Fellowship

Congrats to Dr. Malkanthi Karunananda, who was selected for a 2021 Cottrell Postdoctoral Fellowship from Research Corporation for Science Advancement. The fellowship will support Malkanthi as she pursues computational studies of alkene functionalization reactions using a transient directing group strategy in collaboration with Prof. Ken Houk at UCLA. As part of the fellowship, Malkanthi will also co-teach a primer in computational chemistry for organic chemists. Congrats on this recognition, Malkanthi!

For more information about the program, click here: https://rescorp.org/cottrell-scholars/cottrell-fellowships

Full Account of Ni-Catalyzed Markovnikov Hydroarylation – Now In Press

While alkene hydroarylation methods have advanced rapidly over the past few years, Markovnikov-selective methods remain rare. Last year, we reported Ni-catalyzed hydroarylation of alkenyl carboxylic acid substrates with arylboronic acids, where the Markovnikov or anti-Markovnikov product could be accessed by changing the ligand environment around the metal center. In an Edge Article appearing online today in Chemical Science, we report a full account of our efforts to expand the substrate scope and elucidate the mechanism of the Markovnikov-selective (“ligand-free”) version of this method. Effective reaction conditions for alkenyl sulfonamides, ketones, and amides were identified, and detailed mechanistic studies suggested that the turnover-limiting and regiodetermining step is arylboronic acid transmetalation. Bravo to Zi-Qi, Omar, and Ruohan on this tour de force.

Click here for a link to the article in Chemical Science: https://pubs.rsc.org/en/content/articlelanding/2021/sc/d1sc03121j#!divAbstract

As a reminder, a pre-print of this article appeared back in May: https://chemrxiv.org/engage/chemrxiv/article-details/60c7592dbb8c1a05f33dcb81

W-Catalyzed Isomerization–Hydroborylation Pre-Print Posted

Team Tungsten strikes again—with their latest pre-print appearing online today in ChemRxiv. This manuscript describes use of W(0) to catalyze site-selective isomerization–hydroboration of simple alkenyl amides. Conceptually, this work shows that native carbonyl groups can facilitate controlled alkene isomerization to otherwise disfavored positions, allowing for selective functionalization at classically inaccessible sites. Additionally, not only does this report mark the first use of W to catalyst a hydroboration reaction, it also demonstrates that W exhibits unique regioselectivity that complements that of existing methods with Rh and Ir. Congrats to the team, G4 student Tanner, visiting grad student Raul, and postdoc Phillippa. This study was performed in collaboration with Raul’s home lab, that of Prof. Rubén Martin at ICIQ in Tarragona, Spain.

For a link to the pre-print, click here: https://chemrxiv.org/engage/chemrxiv/article-details/60e77eb2551cb06ecbadb7a4

Ni-Catalyzed Alkenyl Ketone 1,2-Diarylation – Now In Press

The latest paper from Team Nickel is now in press in Organic Letters. In this project, former visiting student Roman teamed up with current graduate student Omar to expand carbonyl-directed alkene 1,2-diarylation (previously demonstrated with amides and carboxylates) to even more challenging alkenyl ketones. Suppressing unwanted alkene isomerization proved to be challenging due to the acidity of the α-C–H bonds, requiring exhaustive (and exhausting!) reaction optimization. We performed a series of mechanistic experiments which collectively support L-type carbonyl coordination, and we compared the efficiency of these reaction conditions to those from related methods across three different substrate families to better understand the similarities and differences. Congrats to the whole team, which (in addition to Roman and Omar) includes Joe, Malkanthi, Zi-Qi, Van, and our BMS collaborator Steve.

For a link to the paper, click here: https://pubs.acs.org/doi/10.1021/acs.orglett.1c01447,

As a reminder, an earlier version of this manuscript appeared as a pre-print back in March: https://chemrxiv.org/engage/chemrxiv/article-details/60c755b19abda2146bf8e413