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Organometallics 1991, 10, 3498-3503
(PCy3)(pyridine),][Fe2(CO)s(p-C~PCy3)] (4c). Pyridine can be removed by prolonged pumping under high vacuum,
and 1 is recovered. Addition of 1 equiv of [CU(CH~CN)~]PF, and PCy, to 4b also yields 1. On the other hand, the reaction between 1 and Na2[Fe2(CO)8]in T H F results in 4a. Sodium amalgam reacts with 1 to reduce Cu(1) in the cluster to Cu(0). The overall reaction proceeds in two steps as shown in Scheme 11. Similarly, the reaction of 1 with KH reduces Cu(1) and proceeds in two steps. In both reactions above, the intermediate products are sodium and potassium salts of 4 (4a,d). Both 1 and 4 are protonated by HBF4.0Eb. Protonation of 1 causes the reduction of Cu(1) to Cu(0) and the oxidation of [Fe2(CO),]" to Fe3(C0)12.Protonation of 4a with 1 equiv of HBF4.0Et2produces 1/2 equiv of 1 and a mixture of intractable materials. Protonation of 4a with HCl was also performed in THF-d8at -80 "C. The reaction was
monitored by variable-temperature 'H and 31P NMR spectroscopy. The attempt to observe possible intermediate products [(p-H)Fe,(CO),G-CuPCy,)] and H2Fe2(CO)s failed; instead, 1 was observed even at -80 "C. The other products or decomposed material could not be definitely identified. Acknowledgment. This work was supported by the National Science Foundation through Grant CHEs800515. NMR spectra were obtained at the Ohio State University Campus Chemical Instrument Center funded in part by NSF Grant 79-10019 and NIH Grant 1S10 PR014051801A. H.D.thanks BP America for a fellowship. Supplementary Material Available: Listings of calculated hydrogen atom positional parameters, anisotropic thermal parameters, bond distances, and bond angles for l, 3,4b.0.5THF, and 7 (28 pages);listings of structurefador amplitudes (168 pages). Ordering information is given on any current masthead page.
Palladium( I1)-Catalyzed Exchange and Isomerization Reactions. 14.' Kinetics and Stereochemistry of the Isomerization and Water Exchange of 2-(Methyl-d3)-4-methyl-l ,I,I ,5,5,5-hexafluoro-3-penten-2-ol in Aqueous Solution Catalyzed by PdCI:-: Two New Mechanistic Probes for Catalytic Chemistry John W. Francis and Patrick M. Henry* Department of Chemistty, Loyola University of Chicago, Chicago, Illinois 60626 Received February 7, 1997
The isomerization of 2-(methyl-d3)-4-methyl-l,l,l,5,5,5-hex~uoro-3-~nten-2-ol (2a) into an equilibrium (2b) in aqueous solution was mixture of 2a and 2-methyl-4-(methyl-d3)-l,l,l,5,5,5-hex~uor~3-~n~n-2-ol studied by 'H and 2H NMR, under the Wacker conditions of low chloride (x1.0 M) and acid (
