Ligand Scaffold Optimization in Rhodium-Catalyzed Asymmetric Hydrogenation

Ligand Scaffold Optimization in Rhodium-Catalyzed Asymmetric Hydrogenation 

We found this to be the case in each of the reaction s we have examined thus far, and it presents an important, rather unique opportunity to learn something of fundamental importance with respect to catalyst substrate generality. Why, within a series of closely related scaffolds, do some exhibit good, others poor, substrate generality Admittedly, two substrates is only a modest step toward substrate generality, but hopefully it illustrates another unique feature of the approach. It is also noteworthy that, while the data are not shown here, we see similar trends for substrate conversion and product yield as a function of SAL scaffold. This must relate to turnover frequency and/or catalyst stability and, hopefully, it will prove possible to gain new insights into these issues of fundamental importance in catalysis in the course of future studies. 

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Ligand Scaffold Optimization in Rhodium-Catalyzed Asymmetric Hydrogenation 249 Ph ... 

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