Document Type
Article
Publication Date
Spring 3-3-2016
Department
Chemistry
Abstract
The synthesis, characterization and catalytic activity of new ruthenium complexes of the tris-N-pyrrolyl phosphine ligand P(pyr)3 is described. The new ruthenium complexes [RuCl(ind)(PPh3){P(pyr)3}] and [RuCl(ind){P(pyr)3}2] (ind = indenyl ligand η5-C9H7−) were synthesized in 73% and 63% isolated yield, respectively, by thermal ligand exchange of [RuCl(ind)(PPh3)2] with P(pyr)3. The electronic and steric properties of the new complexes were studied through analysis of the X-Ray structures and through cyclic voltammetry. The new complexes [RuCl(ind)(PPh3){P(pyr)3}] and [RuCl(ind){P(pyr)3}2] and the known complex [RuCl(ind)(PPh3)2}] differed only slightly in their steric properties, as seen from the comparable bond lengths and angles around the ruthenium center. The oxidation potentials of [RuCl(ind)(PPh3){P(pyr)3}] and [RuCl(ind){P(pyr)3}2] are +0.34 and +0.71 Volt vs. Cp2Fe0/+, which are substantially higher than that of [RuCl(ind)(PPh3)2] (−0.023 V), which is in accordance with the enhanced π-acidity of the P(pyr)3 ligand. The new complexes are catalytically active in the etherification of propargylic alcohols and in the first ruthenium-catalyzed formation of known and new xanthenones from propargylic alcohols and diketones (18 to 72 h at 90 °C in ClCH2CH2Cl or toluene, 1-2 mol-% catalyst, 69-22 % isolated yields).
Recommended Citation
Stark, Matthew J.; Shaw, Michael J.; Rath, Nigam P.; and Bauer, Eike B., "Synthesis, Structural Characterization and Catalytic Activity of Indenyl tris-N-Pyrrolyl Phosphine Complexes of Ruthenium" (2016). SIUE Faculty Research, Scholarship, and Creative Activity. 30.
https://spark.siue.edu/siue_fac/30
Comments
The ruthenium pyrrolyl phosphine complexes [RuCl(ind)(PPh3){P(pyr)3}] and [RuCl(ind){P(pyr)3}2] were synthesized, and exhibited increased oxidation potentials due to the π-acidic pyrrolyl phosphine ligands. The complexes are catalytically active in the etherification of propargylic alcohols and in the formation of known and new xanthenones from propargylic alcohols and diketones.
This is the peer reviewed version of the following article:
Stark, M. J., Shaw, M. J., Rath, N. P. and Bauer, E. B. (2016), Synthesis, Structural Characterization, and Catalytic Activity of Indenyl Tris(N-pyrrolyl)phosphine Complexes of Ruthenium. Eur. J. Inorg. Chem., 2016: 1093–1102. doi: 10.1002/ejic.201501381
which has been published in final form at http://dx.doi.org/10.1002/ejic.201501381. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.