Stephan’s group

Stephan s group have recently turned their attention to the reactivity of ruthenium bis-NHC complexes, probing a mixed system 27 containing a... 

The concept of frustrated Lewis pairs (FLP) in which Lewis acid-base couples formed by sterically crowded phosphines and pentafluoro-phenylboranes are sterically precluded from adduct formation, which was established and significantly developed by Stephan s group, has been reviewed by the latter. FLP open alternative reaction pathways and the discovery of their reactivity, even in its infancy, brings a new perspective to the area of small molecule activation and applications in catalysis. 

The reactivity of a tris(aminophosphine) ligand of the type iV-(NP)3 was scrutinized by Stephan s group, giving an extensive family of Ru complexes that could be easily transformed into many other derivatives (Scheme 13). For instance, the complex 51 was transformed into 52 just upon standing in solution. Deprotonation of the phosphonium center in 52, followed by anion exchange, generated the Ru hydride complex 53 with a 1 M solution of HCl in diethyl ether. This complex could be transformed into several other complexes. 

Blum, S., Fiedler, H. P., Groth, I., Kempter, C., Stephan, H, Nicholson, G, Metzger, J., and Jung, G. (1995) Biosynthetic capacities of Actinomycetes. 4 Echmoserine, a new member of the quinoxaline group, produced by Streptomyces tendae. J. Antibiot. 48,619-625. 

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