The effect of vicinyl olefinic halogens on cross-coupling reactions using Pd(0) catalysis |
| |
Authors: | Michael G. Organ Haleh Ghasemi Cory Valente |
| |
Affiliation: | The Department of Chemistry, York University, 4700 Keele Street, Toronto, Ont., Canada M3J 1P3 |
| |
Abstract: | (trans) 1-Chloro-2-iodoethylene (3), (trans) 1-bromo-2-iodoethylene (4), (trans) 1,2-diiodoethylene (5) and (cis and trans) 1,2-dibromoethylene (11) were reacted under Suzuki, Sonogashira and Negishi cross-coupling conditions using Pd catalysis to obtain mono coupled products. Only olefin template 3 provided the desired coupling products reliably under all reaction conditions. Compound 5 did not provide cross coupled products under any of the reaction conditions used. The Negishi reaction was the only one that worked for templates 4 and 11. Studies indicate that oxidative addition of the most reactive carbon-halogen bond to Pd(0) is followed by elimination of the second halide, when the second halide is a bromide or an iodide. This happens to a much lesser degree when the second halogen is a chloride. |
| |
Keywords: | Palladium Catalysis Cross coupling |
本文献已被 ScienceDirect 等数据库收录! |
|