Totally Synthetic by Paul H. Docherty, 11 June 2006
Total Synthesis of 2-Quinuclidonium Tetrafluoroborate
Brian M. Stoltz
K. Tani, B. M. Stoltz, Nature 2006, 441, 731-734.
Just a quick update to point out Stoltz’s synthesis in Nature. This little molecule has been the burden of much discussion and controversy in the community, and the accompanying X-ray is very interesting. As you can see, it’s an anti-Bredt amide, where the nitrogen lone pair has been forced out of conjugation from the carbonyl, resulting in a radically different amide chemistry (the N behaves much more like an amine).
After a failed synthesis attempt using C-H insertion of rhodium-stabilized acylcarbenes generated from diazocarbonyl derivatives, they used an intramolecular Schmidt-Aubé reaction to complete the bicyclic lactam. From a personal standpoint, I find it great that they point out what didn’t work - this is often more useful than a description of what did. Unfortunately, many short articles and letters such as this fail to bother.