Tuesday, January 26, 2016

Tough-to-Swallow Propargylation

As I thumbed through the recent Tet Lett abstracts, I encountered this title:
"Regioselective propargylation of aldehydes using potassium allenyltrifluoroborate promoted by tonsil"
Turns out, the authors were referring to Tonsil (R), an acid-treated calcium bentonite clay, not the fleshy pockets in the back of the throat associated with immune response. I guess BRSM  doesn't have to update his "Desperate Conditions" list quite yet...

So, in summary:

Source: Sud-Chemie

Not This.

Monday, January 11, 2016

The NMR Laundromat

Source: OPRD / CNRS
The simplest, most practical solutions* are often the best.

I'm reminded of classic papers for pragmatic lab procedures, like Clark Still's on flash chromatography, or Gottlieb & Nudelman's on detecting trace NMR impurities. Everyone has encountered their lab's version of the Kugelrohr setup - run by an old electric kettle and a windshield-wiper motor!

From the ASAP of Organic Process Research and Development comes this handy one-pager: a how-to on cleaning dozens of NMR tubes simultaneously, using glassware readily available in just about any synth lab.

Seeing this instantly triggered a "Well, duh!" moment for me - the amount of time I've stood before a stoppered 500mL vacuum flask impaled with a cannula, washing single tubes by hand...I'm sure it reaches into hours, if not days.

If you try this, leave a comment; I'm really quite interested to see how it turns out. I'd also wonder if OPRD might be angling for other quick one-offs. Couldn't hurt to try, right?

*Of course, I'd be remiss if I didn't point unfamiliar readers to the treasure trove that is Not Voodoo.