ORGN 133 |
| Advances in solid phase organic synthesis (SPOS) led to the development of new technologies for automated parallel synthesis of combinatorial libraries. Recently, we have reported a conversion of palladacycles 1 into diverse benzopyrans and 1,2-dihydroquinolines. To facilitate product isolation, and recovery of auxiliary ligands and palladium, we considered immobilization of palladacycles onto solid supports. Herein we report the preparation of PS-DVB-supported oxapalladacycles, and the survey of effects of the loading with the phosphine functional group (0.9-3.0 mmol P/g), palladium (Pd : P molar ratios), and swelling, on their reactivity. Optimum reactivity was achieved for resins with medium-loading of phosphorus (1.4 mmol P/g), and a high loading with palladium (e.g. Pd : P = 1 : 2.0). The new technology allowed for the preparation of diverse 2H-1-benzopyrans and 1,2-dihydroquinolines in yields better than from the comparable solution phase experiment, notably facilitating the product isolation and purification. Furthermore, feasibility of palladium recovery (70 – 80%) has been demonstrated. In this presentation, development of the methodology, and its application to parallel synthesis of combinatorial libraries of heterocycles will be presented.
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Asymmetric Reactions and Syntheses, Physical Organic Chemistry, Combinatorial Chemistry, Total Synthesis
8:00 PM-10:00 PM, Sunday, 26 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster
Division of Organic Chemistry |
