So…I barely have enough time to read blogs, much less contribute to my own. Still, I felt an urge to publicize the latest offerings from the UIUC organic department. First, and I know I’m on the bandwagon late on this one, is Aaron Finke’s Organic Letters paper on using Hartwig’s C-H activation chemistry to synthesize 1,3,5-phenylene dendrimers (for non-chemistry readers: really big molecules).
On JACS ASAP today is a paper by Eric Gillis from the Burke group, detailing the surprising stability of their MIDA-protected boronates under a number of common reaction conditions (most notably, oxidation and aldol conditions). The paper demonstrates that, by introducing MIDA early in a synthetic route, boron can be carried through a series of synthetic steps and finally deprotected to afford a product that can undergo cross coupling. The development of MIDA certainly represents a breakthrough in the iterative cross coupling of boronic acids, although I’m not on its nuts as much as some people are. Call me crazy, but I feel like iterative cross coupling is a smidge overrated.
For the uninitiated, iterative cross coupling is the repeated formation of C-C bonds via cross coupling of substrates with protected coupling functionality. To build up long chains of arenes or polyenes, you can just couple, deprotect, couple, deprotect, couple…you get the idea. In practice, of course, things get more difficult with each coupling, but theoretically this could be carried on FOREVER! It’s great for polymer chemistry, it’s neat, and it’s an Illinois thing; I’ll give it that. I’ve never been much for the latest thing. It’ll take a few more natural product syntheses, and a couple not from the Burke group, to convince me that this synthetic methodology will endure.