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Wesley G. Bentrude ORGANIC CHEMISTRY Professor B.S., 1957, Iowa State University Ph.D., 1961, University of Illinois Postdoctoral, 1963, University of Pittsburgh. Phone: 801-581-7604 Office: Email: bentrude@chem.utah.edu Research Group Publications

Activities & Awards

• Alexander von Humboldt Fellow, 1977, 1981
• David P. Gardner Fellowship, 1981
• Professor Associe, Universite of Aix-Marseille, 1983
• Distinguished Service Award, Utah Academy of Sciences, Arts and Letters, 1994
• Robert W. Parry Teaching Award in Chemistry, 1994
• University of Utah Distinguished Research Award, 1995
• Fellow, AAAS, 1994
• Editorial Advisory Boards, Trends in Organic Chemistry, Phosphorus Sulfur Silicon, Current Medicinal Chemistry, Recent Developments in Organic Chemistry

Research Interests

Organic molecules containing phosphorus offer fascinating possibilities for structural, synthetic and mechanistic study. Besides being crucial biomolecules in metabolic processes, they find important practical applications: e.g., as anticancer and antiviral drugs, immunosuppressives, insecticides, and fuel and lubricant additives.

Unusual photochemical rearrangements discovered in our laboratory are being investigated from a mechanistic standpoint and also with regard to their applicability to synthesis. For example, the triplet excited states of allyl phosphites rearrange to allylphosphonates, presumably via the 1,3-biradical, I. The same overall rearrangement occurs when the excited singlet of 9,10-dicyanoanthracene accepts an electron from the p bond or from the lone pair on phosphorus to yield a cation radical that cyclizes to presumed intermediate II. These reactions are being employed in the synthesis of nucleoside-based phosphonates with potential antiviral or antitumor activity.

Arylmethyl phosphites (III) photorearrange readily to (V). Mechanistic considerations of the potential intermediacy of free radical pairs (IV), their singlet or triplet multiplicity, and the stereochemistry at the carbon site of migration are of particular interest.

Very recently we have shown that vinyl radical (VI) from cyclization of the 6-hexynyl radical is trapped by (MeO)3P to yield vinylphosphonates (VII). The regiochemistry of this process and its application to synthesis of phosphonates of biological and medicinal chemical interest are under investigation.

Selected Publications

• Photo-Arbuzov Rearrangements of Dimethyl Benzyl and Dimethyl p-Acetylbenzyl Phosphite, S. Ganapathy, B.B.V. Soma Sekhar, S.M. Cairns, K. Akutagawa, W.G. Bentrude, J. Am. Chem. Soc.,121, 2085-2096 (1999).
• Vinylphosphonate Formation via a Novel Cyclization-Vinyl Radical Trapping Sequence, X.-Y. Jiao,W.G. Bentrude, J. Am. Chem. Soc., 121, 6088-6089 (1999).
• Free Radical and Photochemical Routes to Phosphonate Oligonucleotide Precursors , A.E. Sopchik, X.Y. Jiao, W.G. Bentrude, Phosphorus, Sulfur & Silicon, 144-146, 373-376 (1999).
• SET-Induced Photorearrangement of 2-Phenylallyl Phosphites. Stereochemistry at Phosphorus. Application to Cyclic Nucleotide Derivatives.David C. Hager, Alan E. Sopchik, and Wesley G. Bentrude, JOC, 65, 2778-2785 (2000).
• Triplet-Sensitized Photorearrangements of Six-Memberd-Ring 2-Phenylallyl Phosphites. Reaction Efficiency and Stereochemistry at Phosphorus, D. Hager, W.G. Bentrude, JOC, 65, 2786-2791 ( 2000).
• Laser Flash Photolysis Evidence for Styryl Radical Cation Cyclization in the SET-Induced Photorearrangement of p-Methoxy-Substituted 2-Phenylallyl Phosphite, D. Shukla, C. Lu, N.P. Schepp, W.G. Bentrude, L.J. Johnston, J. Org. Chem. 65, 6167-6172 (2000).
• Photo-Arbuzov Rearrangements of 1-Arylethyl Phosphites: Stereochemical Studies and the Question of Radical-Pair Intermediates, W. Bhanthumnavin, W.G. Bentrude, J. Org. Chem., 66, 980-990 (2001).
• Effects of Structure on the Free Radical Reactions of Hydridophosphoranes with Dimethyl Sulfide, M. Garrossian, W.G. Bentrude, G.-V. R�senthaler, J. Org. Chem., 66, 6181-6184 (2001).
• G.S. Jeon, W.G. Bentrude, "Nucleoside Analog-Based Phosphonates via Photochemical Single Electron Transfer (SET) Induced Rearrangements of Allyl Phosphites," Tetrahedron Lett. 39, 927-930 (1998).
• K. P. Dockery, W. G. Bentrude, "Free Radical Chain Reactions of [1.1.1]Propellane with Three-Coordinate Phosphorus Molecules. Evidence for the High Reactivity of the Bicyclo[1.1.1]pent-1-yl Radical," J. Am. Chem. Soc. 119, 1388-1399 (1997).
• W.G. Bentrude, K.P. Dockery, S. Ganapathy, S.-G. Lee, M. Tabet, Y.-W. Wu, R. T. Cambron, J.M. Harris, "Triplet Sensitized Photorearrangements of 2-Phenylallyl Phosphites," J. Am. Chem. Soc. 118, 6192-6201 (1996).
• �Y. Huang and W.G. Bentrude, "Conformational Equilibria of Phosphoranes with 5-Alkyl Substituted 1,3,2,-Dioxaphosphorinane Rings Attached Diequatorially to Five-Coordinated Phosphorus. Are Boat/Twist Conformations Populated?" J. Am. Chem. Soc. 117, 12390 (1995).
• I.V. Koptyug, N.D. Ghatlia, G.W. Sluggett, N.J. Turro, S. Ganapathy, W.G. Bentrude, "Investigation of the Photolysis of Phosphites by Time Resolved Electron Spin Resonance," J. Am. Chem. Soc. 117, 9486-9491 (1995).
• W.G. Bentrude, "Steric and Stereoelectronic Effects in 1,3,2-Dioxaphosphorinanes," S. Ganapathy, K.P. Dockery, A.E. Sopchik and W.G. Bentrude, "Photoinduced Single Electron Transfer Initiated Rearrangements of 2-Phenylallyl Phosphites," J. Am. Chem. Soc. 115, 8863 (1993).
• Y. Huang, A.E. Sopchik, A.M. Arif and W.G. Bentrude, "NMR and X-ray Evidence for the Chair Conformation of Six-Membered Rings Attached Diequatorially to Five-Coordinate Phosphorus. Implications for Reported Transition State Analogs of Nucleoside Cyclic 3',5'-Monophosphate Hydrolysis," J. Am. Chem. Soc. 115, 4031 (1993).