Fluorous Grubbs Catalysts

Y. Kobayoshi, S. Inukai, T. Watanabe, Y. Sogiyama, H. Hamamoto, T. Shioiri, M. Matsugi, A medium fluorous Grubbs-Hoveyda 2nd generation catalyst for phase transfer catalysis of ring closing metathesis reactions. Tet. Lett. 56(11), 1363-1366 (2015)... 

Matsugi M, Curran DP (2005) Synthesis, reaction, and recycle of light fluorous Grubbs-Hoveyda catalysts for aUcene metathesis. J Org Chem 70 1636-1642... 

Scheme 7.20 Fluorous Grubbs s catalyst and related reactions.

Figure 7.14 Comparison of conventional Grubbs second generation metathesis catalyst (left) and Gladysz s fluorous version (right).

Scheme 1.7 Synthesis of natural product-like molecules with unprecedented scaffold diversity. Initially, building blocks were added iteratively to a fluorous-tagged linker, with intermediates purified by fluorous-solid phase extraction. Metathesis cascades were used to reprogramme the scaffolds and to release final products from the fluorous-tagged linker. Reagents and conditions. (1) Grubbs first-generation catalyst, 21a 23% 21b 56% (2) fluorous-tagged Hoveyda-Grubbs second-generation eatalyst, 21c 33%.

Examples of using functionalized, fluorinated carboxylates as alternative X-type ligands for the generation of supported catalyst analogs were previously introduced in section The Attachment of Grubbs-Type Catalysts via the X-Type Ligand . However, the introduction of fluorous functionalities within the catalyst architecture can also be employed to aid in product isolation and to effectively recover/recycle a catalyst via fluorous extraction [141]. Although similar to the IL systems that were discussed in the previous section, this approach instead uses... 

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