In asymmetric olefin metathesis reactions, the addition of halide additives is often required to augment enantioselectivities, despite the fact that the additives result in catalysts with diminished reactivities. The preparation of new chiral Ru-based catalysts was accomplished by exploiting previously reported mechanistic studies. The catalysts possess a high level of reactivity and successfully induce high levels of asymmetry in desymmetrization reactions without the use of halide additives.

To facilitate a drug discovery project, we needed to develop a robust asymmetric synthesis of (2S,5S)-5-substituted-azepane-2-carboxylate derivatives. Two key requirements for the synthesis were flexibility for elaboration at C5 and suitability for large scale preparation. To this end we have successfully developed a scalable asymmetric synthesis of these derivatives that starts with known hydroxy-ketone 8. The key step features an oxidative cleavage of aza-bicyclo[3.2.2]nonene 14, which simultaneously generates the C2 and C5 substituents in a stereoselective manner.

Alkaloide der Naamin‐Familie wurden in nur zwei Stufen ausgehend von diversen Propargylaminen synthetisiert (siehe Schema: R1=Me, R2=substituierter Benzylrest, R3=Ar). Die Addition eines Propargylamins an ein in situ erzeugtes Carbodiimid, eine Silber(I)‐katalysierte intramolekulare Hydroamidierung und anschließendes Entschützen führen zum zentralen Heterocyclus zahlreicher Naturstoffe und biologisch aktiver Verbindungen. Boc=tert‐Butoxycarbonyl, Cbz=Carbobenzyloxy.

2-Nitriminoimidazolidine and 1 -Nitro-2-nitriminoimidazolidine 6371 alcohol150 (above) and chloride150 (above) showed these substances to be absent, as was 2-methyl-3-phenylbutane15b

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