Rhodium Gets It Done

Interesting, informative intermediates from Rh(I) silylation

In this week's Science, Hartwig and Cheng disclose some pretty swanky C-H activation chemistry. By combining Rh(I) dimer, a really bulky diphosphine ligand, a cheap, bulky hydrosilane, and a hydrogen "acceptor," the pair turn relatively distant aromatic bonds into highly functional silicon handles. In certain cases, tricks like capping a carbazole with a bulky TIPS group direct the silylation para - all the way to the other side of the aromatic ring!

The authors quickly point out that this silylation runs at "low" temps (80 deg C), uses fairly cheap commercially-available reagents, and occurs with almost reversed selectivity to the corresponding direct borylation conditions. But my favorite part comes from a deep dive into the Supporting Information. Far from the discussion of academic over-publishing we've had for the past few days, Hartwig and Cheng really sculpt a great paper here: Stability studies. Reactivity differences (Si vs. B). Cross-couplings. Preliminary mechanistic details.

As always, there's tons more to do. Getting out of the glovebox with a more stable Rh precursor, or translating the reactivity to an earlier metal (a tall order!). Deeper mechanistic studies would certainly show the way. Even more tantalizing? Using single-enantiomer versions of the bulky ligands to incorporate some chiral-at-silicon synthons. I can't wait to see the rest of this story.

Friday Fun: John Hartwig, 2.0

Did I just see a GQ model pop up in my Inbox?

Source: Yale University

The email just dropped in to announce Prof. John Hartwig's receipt of the 2013 ACS Catalysis Lectureship. Kudos to him, he certainly deserves it! Over the past few years, I've truly enjoyed reading his explorations of Ir and Ni catalysis to achieve challenging transformations.

But the shocking part was the photo crop in the upper left corner...what a change! The "Hartwig" I have in my head, circa 2004, was this guy (right). Suit, tie, some distinguished grey in the temples, a demure smile.

But who's this, now? Check out the older, wiser Hartwig, stolen off his new group page at UC-Berkeley (left). What a change!

Source: UC-Berkeley

Gone are the glasses, the bookshelves, and the formal tie. Now we have a slightly more grizzled, more wistful JH, hair scattered by the wind, looking like he could take on the world.

I fully approve.

Happy Friday,
SAO

Knights of the Periodic Table

Last night, while reading through the Feb. 6 issue of C&EN, I found myself terribly amused by the inside back cover. The ad, for ACS journal Organometallics (*now under new management!), encouraged readers to check out their 2011 Roundtable. This panel of distinguished chemists met together last year to opine on issues ranging from new research frontiers and publication strategies to the role of basic research in developing new industrial reactions. 

A hand-drawn cartoon, purportedly of chemists in concilium adorns the article. Clearly, the artist intends for this to be modern-day: laptop computers, desk chairs, and a multinational group discuss science with rapt attention.


But the picture I found so funny wasn't this one, but instead the magazine cartoon, which re-imagined the same meeting as if the chemists were members of King Arthur's court. Which got me to thinking - I've dabbled a bit in catalysis and complexes, so who would I want on my round table?

I've taken the liberty of labeling the photo with my potential knights. Readers, with whom would you want to ride into battle discuss organometallic chemistry?