Abstract
AbstractThe two bis(oxazoline)pyrrole ligand precursors 2,5‐bis(4,4′‐dimethyl‐4,5‐dihydrooxazol‐2‐yl)pyrrole (“dmoxpH”, 2) and 2,5‐bis(4,4′‐dimethyl‐4,5‐dihydrooxazol‐2‐yl)‐3,4‐diethylpyrrole (“Et2dmoxpH”, 5) have been synthesised and metallated by treatment with n‐butyllithium at −78 °C in diethyl ether. Treatment of the lithium pyrrolide with 1.1 mol‐equiv. of [PdCl2(COD)] gave the corresponding helical dinuclear palladium complexes [Pd2Cl2(dmoxp)2] (6) and [Pd2Cl2(Et2dmoxp)2] (7). In both complexes the tridentate bis(oxazolinyl)pyrrolide ligands bridge the two metal centres, with one of the oxazoline rings and the charged pyrrolide being coordinated to the one Pd centre while the second oxazoline ring is twisted relative to the pyrrolide unit and coordinates to the second palladium atom. Complexes 6 and 7 were found to be precursors for active catalysts for Heck coupling reactions of styrene and ethyl acrylate, with turnover numbers of over 9000 for the former, as well as for disubstituted alkenes such as methyl crotonate and methyl cinnamate. Complex 6 was found to be a very active catalyst for Suzuki coupling reactions of activated and deactivated bromoarenes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.