Solid-Supported Cross Metathesis and the Role of the Homodimerization of the Non-immobilized Olefin

Abstract

We have prepared immobilized olefins as models for the cross metathesis using different olefin partners in the presence of second generation Grubbs and Hoveyda-Grubbs precatalysts. We have demonstrated that solid-phase cross metathesis is strongly dependent on the degree of homodimerization of the non-immobilized olefin and the reactivity of such a homodimer. As in the homogeneous phase, the Hoveyda-Grubbs precatalyst was better for immobilized alpha,beta-unsaturated carbonyl compounds.

Toward a Unified Mechanism for Oxoammonium Salt-Mediated Oxidation Reactions: A Theoretical and Experimental Study Using a Hydride Transfer Model

“…1 (E)-Methyl 5-phenyl-pent-2-enoate. 40 The following procedure is a modification of the protocol outlined by Tius and co-workers. 41 To a 100 mL round-bottom flask equipped with a stir bar was added THF (16 mL), followed by dimethyl methoxycarbonylmethanephosphonate (8.01 g, 0.044 mol, 1.1 equiv).…”

Cobalt-Catalyzed Cross-Coupling of Grignards with Allylic and Vinylic Bromides: Use of Sarcosine as a Natural Ligand

“…30 Colorless liquid (338 mg, 64% yield); 1 H NMR (400 MHz, CDCl 3 ): δ (ppm) 3.44 (dd, 2H, J = 6.8 Hz, 1.8 Hz), 3.63 (s, 3H), 5.74 (dt, 1H, J = 15.6 Hz, 1.7 Hz), 6.98-7.12 (m, 3H), 7. 12-7.19 (m, 1H), 7.19-7.27 (m, 2H).…”

Chemo‐ and Regioselectivity Enhancement in Solid‐Supported Reactions

“…To probe the limits of the reaction, aliphatic, aryl, and acryloyl alkenes 8, 11, and 12 were immobilized and reacted with a variety of soluble olefins 13-16 from different classifications based on homodimerization potential (Scheme 6.2). 13 For example, the immobilized acrylate 8 was reacted with several soluble olefins to form the immobilized coupling product 9. Subsequent cleavage with TFA and esterification with diazomethane delivered the esters 10.…”