Professor
Chemistry
Education
Ph.D., Dartmouth College
B.A., Wesleyan University
Research Interests
Application of acyclic (pentadienyl)iron(1+) cations
The reaction of acyclic pentadienyl iron cations (1) with nucleophiles may proceed either at the terminal carbon atoms (path a) and/or at internal positions (path b). The regioselectivity of these reactions depend on the substitutents present on the pentadienyl ligand, the "spectator" ligands attached to iron, and the nature of the nucleophile (ie. heteroatom nucleophiles, or organolithiums, or stabilized carbon nucleophiles), and in certain cases, the nucleophile counterion. (Diene)iron products (2) produced by “path a” are stable, isolable species in which the iron serves as a protecting group for the diene against oxidation, reduction and cycloaddition reactions; decomplexation under oxidative conditions generates the free ligand. (Pentenediyl)iron products produced by “path b”, which bear an electron withdrawing group at C1 (3a) are also stable, isolable species, however decomplexation of these (pentenediyl)iron complexes, via an oxidatively induced-reductive elimination, gives vinylcyclopropanecarboxylates. Additionally, if an alkenyl nucleophile is used, the resultant divinylcyclopropanes may undergo Cope rearrangement to give cycloheptadienes. In contrast, (pentenediyl)iron complexes without an electron withdrawing group at C1 (3b) are unstable and undergo carbon monoxide insertion and reductive elimination to generate cyclohexenones. Thus, the acyclic (pentadienyl)iron(1+) cations serve as a versatile precursor to conjugated dienes, cycloheptadienes, vinylcyclopropanes and cyclohexenones.

We have utilized this reactivity to prepare a variety of natural and non-natural product targets as indicated in Scheme 2.

Generation of molecular complexity from simple hydrocarbons
The use of simple, relatively inexpensive hydrocarbons as starting materials for the synthesis of complex molecules relies on efficient methods for their oxidation, rearrangement and/or functionalization. We have utilized cyclohexadiene as a precursor for a stereochemically diverse spectrum of polyhydroxyaminocyclohexanes (aminocyclitols, Scheme 3). In addition, reaction of (cyclooctatetraene)iron (4) with a variety of electrophiles generates isolable (dienyl)iron cations (5a and b, Scheme 4).


Professional Experience
Professor Donaldson received his B.A. in 1977 from Wesleyan University and his Ph.D. degree in organometallic chemistry from Dartmouth College in 1981. He was a Postdoctoral Research Associate at Brandeis University (1981-82) and a Visiting Assistant Professor at Wesleyan (1982-83) before joining the faculty at Marquette University in August 1983. Professor Donaldson was awarded the Edward D. Simmons Award for Junior Faculty Excellence (1988), the Rev. John R. Raynor Faculty Award for Teaching Excellence (1995), and a Alexander von Humboldt Research Fellow at Philipps- Universitaet Marburg, Germany (1990-91). He was a visiting Professor of the University of Strathclyde (Glasgow) for Jan-June 2015 and Feb-March 2019.
Selected Publications
- “Evaluation of a-hydroxycinnamic acids as pyruvate carboxylase inhibitors”, D. J. Burkett, B. N. Wyatt, M. Mews, A. Bautista, R. Engel, C. Dockendorff, W. A. Donaldson and M. St. Maurice, Bioorg. Med. Chem. 2019, 27, 4041-4047.
- “Synthesis and Evaluation of 4-Cycloheptylphenols as Selective Estrogen Receptor-Beta Agonists (SERBAs)”, K. L. I. S. Perera, A. M. Hanson, S. Lindeman, A. Imhoff, X. Lu, D. S. Sem and W. A. Donaldson, Eur. J. Med. Chem. 2018, 157, 791-804.
- “A-C Estrogens as Potent and Selective Estrogen Receptor-Beta Agonists (SERBAs) to Enhance Memory Consolidation under Low-Estrogen Conditions”, A. M. Hanson, K. L. I. S. Perera, J. Kim, R. K. Pandey, N. Sweeney, X. Lu, A. Imhoff, A C. Mackinnon, A. J. Wargolet, R. M. Van Hart, K. M. Frick, W. A. Donaldson and D. S. Sem, J. Med. Chem. 2018, 61, 4720-4738.
- “Reactivity of (1-methoxycarbonylpentadienyl)iron(1+) cations with hydride, methyl, and nitrogen nucleophiles”, Y. Ma, Y. K. Yun, J. Wondergem, A. Sar, J. R. Gone, S. Lindeman and W. A. Donaldson, Tetrahedron 2017, 73, 4493-4500.
- “Reactivity of acyclic (pentadienyl)iron(1+) cations with phosphonate stabilized nucleophiles: Application to the synthesis of oxygenated metabolites of carvone”, D. W. Lee, C. F. Manful, J. R. Gone, Y. Ma and W. A. Donaldson, Tetrahedron 2016, 72, 753-759.
- “Generation of Molecular Complexity from Cyclooctatetraene: Preparation of Aminobicyclo[5.1.0]octitols”, M. F. El-Mansy, M. Flister, S. Lindeman, K. Kalous, D. S. Sem and W. A. Donaldson, Chem. Eur. J. 2015, 21, 10886-10895.
- “Preparation of cyclohexenones from acyclic (pentadienyl)iron(1+) cations: Synthetic studies directed toward the A-ring of dihydrotachysterols”, C. F. Manful and W. A. Donaldson, Eur. J. Org. Chem. 2014, 6787-6795.
- “Probing the human estrogen receptor-a binding requirements for phenolic mono- and di-hydroxyl compounds: a combined synthesis, binding and docking study”, Bioorg. Med. Chem. 2014, 22, 303-310.
- “Generation of Molecular Complexity from Cyclooctatetraene Preparation of Optically Active Protected Aminocycloheptitols and Bicyclo[4.1.0]undecatriene”, M. F. El-Mansy, A. Sar, S. Lindeman and W. A. Donaldson, Chem. Eur.J. 2013, 19, 2330-2366.
- “Generation of molecular complexity from cyclooctatetraene using dienyliron and olefin metathesis methodology”, M. F. El-Mansy, A. Sar, S. Chaudhury, N. J. Wallock and W. A. Donaldson, Org. Biomol. Chem. 2012, 10, 4844-4846. doi: 10.1039/c2ob25636c
- “Reactivity of acyclic (pentadienyl)iron(1+) cations: Synthetic studies directed toward the frondosins”, D. W. Lee, R. K. Pandey, S. Lindeman and W. A. Donaldson, Org. Biomol. Chem. 2011, 9, 7742-7747. doi: 10.1039/C1OB05720K
- “Synthesis of Hydroxy- and Polyhydroxy-Substituted 1,3-Diaminocyclohexanes”, A. Sar, S. Lindeman and W. A. Donaldson, Synthesis 2011, 924-928. doi: 10.1055/s-0030-1258430