Thursday, June 13, 2013

Friday Fun: Thulium Breaks 'Em Down

Seriously, how often do you see thulium in the chemistry mainstream?

Prof. David Procter and Dr. Michael Szostak, of U. Manchester in England, want you to think of it a lot more often. Their latest ACIEE explores some crazy stunts thulium diiodide can do when mixed with a little alcohol: Blowing apart esters. Reducing arenes. Unwrapping amides (see below):

All thanks to the extra reducing power of this "non-classical" lanthanide salt. At a good 50% more than samarium diiodide, thulium diiodide can inject a single electron into just about any C=O or arene around, and there's evidence that it slips into neighboring C-N bonds to promote fragmentation:

Source: Szostak, ACIEE 2013

Bill Evans (organometallics, not jazz) previously explored this reagent over a decade ago, marketing it as a souped-up SmI2 / HMPA. His study looked at cyclic ketones, which formed adducts with primary iodides in less than a minute with a healthy dose of TmI2(DME). Despite these exciting early results, it appears that thulium took a back burner to the samarium 'craze' of the mid-'00s, and only now gets its chance in the limelight.

Keep an eye out for more TmI2 reactions; after 100 years of new bond-forming reactions, it's nice to see trends to the contrary.

Happy Friday,

Update (6/14/13) - Added Prof. Procter and group website. 
(6/14/13) - Changed lactam to amide - thanks, Anon!


  1. That ain't no lactam!

  2. When I saw the ASAP for a moment I assumed TmI2 was a typo. Interesting to see what new reactivity these reagents might show.

  3. I would gladly accept any substitute for SmI2 that was reliable and reproducible. That stuff is black-magic infused pixie dust. I'd be curious to see how thulium measures up.