Two fresh publications this week on the topic of chiral cyclopentadienyl ligands may be a coincidence. But tested on a very similar substrate set and published in the same journal (Science)? Something must be going on and it does not help that the one group is located in Basel and the other in Lausanne, two cities separated by a distance of only 134 kilometres.
The cyclopentadienyl (Cp) ligand is a very common ligand in catalysis but an asymmetric version is apparently problematic although they have been reported before (example here: DOI). In the Lausanne exploit (DOI) the Cp core is fused with a chiral cyclohexyl group and in the Basel work the appendage is based on biotin (DOI).
No common denominator was found, none of the groups members share a publication or a common employer. There is not even a common grant supplier. Both groups share a long tradition in the subject matter, the Basel group in all sorts of rhodium catalysed enantioselective transformations and the Lausanne group in artificial metalloenzymes and enantioselective catalysis. For both groups the invention seems almost inevitable.
Coincidently the test reaction both groups use (dihydroisoquinoline synthesis via ethylene insertion) was also independently reported by two groups in 2011, one located in Ottawa (DOI) and the other in Münster (DOI) and in the same journal (JACS). So who is the unknown puppeteer?, did the chiral Cp ligand start as a Swiss bar bet? All information volunteered to this blog will be handled confidentially or else there is Twitter.