Here is our most recent addition to the lineup of amphoteric reagents. I refer to alpha-boryl isocyanides. These molecules enable synthesis of boron-containing peptides and heterocycles. Adam Zajdlik (about to start his second year of PhD in my lab) developed these species… Check out the photo – these are white solids (and they do not stink the way most isocyanides do… We call them “peer-friendly” isocyanides…)
If you want to know some history, the isocyanides emerged on the heels of some superb foundational work by my former PhD student Zhi He (now doing his post-doctoral work with Tim Jamison at MIT). Zhi developed alpha-boryl aldehydes using MIDA group on boron:
We were happy to publish this chemistry in response to questions I have been getting at conferences ever since we disclosed the aziridine aldehyde synthesis with Ryan Hili. People were asking me: “OK… the amine/aldehyde combo is cool, but can you think of a molecule where a carbon nucleophile is orthogonal to the aldehyde group?” Thanks to Zhi, we have an answer!
I want to end this post by saying that the unusual stability of our growing line-up of borylated reagents is due to the MIDA functionality, which has been popularized by Marty Burke (http://www.scs.illinois.edu/burke/). Marty has done some pioneering work with MIDA boronates.