Recyclable and chiral ruthenium-based metathesis catalysts for organic and combinatorial synthesis.

摘要

Chapter 1. During mechanistic studies of Ru-catalyzed styrenyl ether to chromene transformations, we accidentally discovered the in situ formation of Ru-chelate complex i. Notably, i is exceptionally robust and recyclable: the catalyst is recovered in high yield after a reaction by air-driven silica gel chromatography and can be reused in additional transformations.*; Chapter 2. This chapter describes the synthesis and study of a more active recyclable monomeric catalyst (see ii above). Confident that organometallic dendrimers would provide an improved catalyst recycling strategy by precipitation or microfiltration techniques, convergent syntheses of compounds iv and v were also optimized. These multi-component catalysts match the activity of the corresponding monomers (i and ii) but, by virtue of their increased polarity, offer the advantage of being more readily isolable from product streams.*; Chapter 3. Complex ii has been immobilized using a new approach for the surface derivatization of small glass (sol-gel) pellets. The practicality of the glass-bound Ru complex ( vi) in high-throughput synthesis was demonstrated by the synthesis of two olefin metathesis libraries.*; Chapter 4. A preliminary study of the synthesis, structure, and reactivity of a new chiral Ru-based catalyst (vii) was recently completed. The representative AROM/CM reactions shown below highlight the significant potential of this system in asymmetric synthesis.; Chapter 5. A brief survey of polymer-supported Ru- and Mo-based metathesis catalysts is provided.*; *Please refer to dissertation for diagrams.