Alkene Metathesis
The keen interest in olefin metathesis dates back to the outset of Prof. Fürstner's independent career in the early 1990s. Our early work showed the outstanding performance of the then brand-new molybdenum and ruthenium alkylidene complexes developed by Schrock and Grubbs, respectively, for the preparation of medium-sized and macrocyclic rings. Rules were spelled out how to implement ring closing metathesis into retrosynthetic planning and examples were published that showcased the complementary logic of this transformation.
Subsequent work aimed at the development of even better catalysts (ruthenium allenylidenes and -indenylidenes, “second generation” ruthenium carbenes endowed with NHC ligands etc.), some of which are now commercially available. A rapid parallel assay was established to test the performance of new catalysts by IR thermography. Moreover, the first examples of metathesis reactions in supercritical carbon dioxide were reported, which showcased the advantages of this particular medium in the formation of macrocyclic fragrance ingredients as well as in ROMP polymerizations.
Our recent discovery that the geminal hydrogenation of alkynes leads to the formation of discrete ruthenium carbenes has opened unexpected new opportunities: “Hydrogenative enyne metathesis” and related transformations are subject to intense scrutiny in this laboratory.
Significant efforts are made to demonstrate the strategic advantages of alkene metathesis for advanced organic synthesis in general. Starting from early work on macrocyclic musks, the group has gone on to the total synthesis of much more demanding polyketides, alkaloids, terpenes, and glycolipids. Thus, our early pioneer studies into medium-sized and macrocyclic rings (lasiodiplodin, gloeosporone, dactylol, jasmine ketolactone) were surpassed in structural and conceptual terms by total syntheses of targets as complex as roseophilin, nonylprodigiosin, tricolorin, balanol, zearalenone, herbarumin, salicyclihalamide, lactimidomycin, woodrosin, ambidinolide B, G, H and T, isooncinotine, ipomoeassin and iejimalide.
Additional information is available on our homepage “Natural Product Chemistry” and the following presentation.