David Lemal

Research Professor

Albert W. Smith Professor of Chemistry Emeritus

Professor Lemal's group is interested in the synthesis and chemistry of unusual organic species, both stable and short-lived, and in the mechanism of organic reactions. Their efforts are focused in organofluorine chemistry. Fluorocarbons and derived materials have found a wide variety of applications in commerce and industry, but there is much to be learned about fundamental aspects of the field and a great need for new synthetic methodology. Among the fascinations of this vast area are the dramatic contrasts in properties and chemical behavior which exist between fluorocarbons and their hydrocarbon counterparts. The Lemal research group is engaged in the synthesis and study of target molecules chosen both for the synthetic challenges they pose and for insights they can afford into questions about structure, properties, reactivity and/or mechanism in organofluorine chemistry. Many of the targets incorporate strained rings and/or highly reactive conjugated systems. Orbital topology-controlled reactions figure prominently in this chemistry, and photochemistry plays an important role as a source of both synthetic methods and mechanistic puzzles.

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He became an Instructor at the University of Wisconsin in 1958 and an Assistant Professor in 1960. In 1965 he joined the Dartmouth Chemistry Department as Associate Professor and served as Chairman during 1976-79. In 1981 he was named the Albert W. Smith Professor of Chemistry. He became emeritus in 2006, but continues to conduct research.

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Department:
Chemistry
Education:
A.B. Amherst College
Ph.D. Harvard University

Selected Publications

Junk, C. P.; He, Y.; Zhang, Y.; Smith, J. R.; Gleiter, R.; Kass, S. R.; Jasinski, J. P.; Lemal, D. M. "Synthesis and Properties of the Strained Alkene Perfluorobicyclo[2.2.0]hex-1(4)-ene,"J. Org. Chem. 2015, 80, 1523-32.

Lemal. D. M.; Akashi. M.; Lou, Y.; Kumar, V. "Tetrafluorothiophene S,S-Dioxide: A Perfluorinated Building Block," J. Org. Chem. 2013, 78, 12330-37.  Selected as a Featured Article.

Ramanathan, S.; Sang, D.; Kumar, V.; Lemal, D. M. "Synthesis of Tetrafluorocatechol" In "Efficient Preparations of Fluorine Compounds;" Roesky, H. W., Ed.; Wiley: Hoboken, NJ, 2013; Chap. 41.

Buzby, J. M.; Barefoot, A. C., III; Grayston, M. W.; Laganis, E. D.; Waldron, R.F.; Lemal, D. M. "Synthesis of Octafluorocyclooctatetraene" In "Efficient Preparations of Fluorine Compounds;" Roesky, H. W., Ed.; Wiley: Hoboken, NJ, 2013; Chap. 49.

Kumar, V.; Ramanathan, S.; Sang, D.; Chen, X.; Lemal, D. M. "The Multifaceted Reactivity of o-Fluoranil," J. Org. Chem. 2012, 77, 966-70.

Kumar, V.; Lemal, D.M. "Photochemistry of o-Fluoranil," J. Org. Chem. 2012, 77, 5017-21.

Lemal, D. M. "Chemistry of Hexafluorobicyclo[1.1.0]butane: A Computational Study," J. Org. Chem. 2010, 75, 6411-5.

Lemal, D. M.; Sang, D.; Ramanathan, S. "o-Fluoranil: Stereochemistry and Mechanism of its Diels-Alder Reactions," J. Org. Chem. 2009, 74, 7804-11.

Lemal, D. M.; Ramanathan, S. "Fluorinated Three-Membered Ring Heterocycles," In Fluorinated Heterocyclic Compounds; Petrov, V. A., Ed.; Wiley: Hoboken, NJ, 2009; pp 3-64.

Lemal, D. M. "The Effect of Fluorine Substitution on Ring Inversion in Bicyclo[1.1.0]butanes," J. Org. Chem. 2009, 74, 2413-6.

Lemal, D. M.; Ramanathan, S.; Shellito, J. "o‑Fluoranil Chemistry: Diels-Alder versus Hetero-Diels-Alder Cycloaddition," J. Org. Chem. 2008, 73, 3392-6.

Ralli, P.; Zhang, Y.; Lemal, D. M. "Perfluorobarrelene," Tetrahedron Lett. 2008, 49, 7349-51.

Chen, X.; Lemal, D. M. “Functionalization of Saturated Fluorocarbons With and Without Light,” J. Fluorine Chem. 2006, 127, 1158-67.

Wei, Y.; Liu, Y.; Wong, T.; Lemal, D. M. “Extremely Facile Ring Inversion and Rearrangement in Fluorobicyclo[2.1.0]pentanes,” J. Fluorine Chem. 2006, 127, 688-703.

   Lemal, D. M. "Perspective on Fluorocarbon Chemistry," J. Org. Chem. 2004, 69, 1-11.

He, Y.; Junk, C. P.; Lemal, D. M. “A Remarkable Propellane,” J. Am. Chem. Soc. 2003, 125, 5590-1.

Lou, Y.; Chang, J.; Jorgensen, J.; Lemal, D. M. “Octachloroazulene,” J. Am. Chem. Soc. 2002, 124, 15302-15307.

Lemal, D. M. “Hexafluorobenzene Photochemistry: Wellspring of Fluorocarbon Structures”, Acc. Chem. Res. 2001, 34, 662-671.

Lemal, D. M. "Flogging the Fluorocarbons," In Fluorine Chemistry at the Millenium. Fascinated by Fluorine; Banks, R. E., Ed.; Elsevier Science: New York, 2000; Chap. 20.

Liu, Y.; Lemal, D. M. "Thermodynamics of a Diaminocarbene-Tetraaminoethylene Equilibrium," J. Am. Chem. Soc. 1999, 121, 10626.

Zhang, Y.; Smith, J.; Lemal, D. M. "Octafluorobicyclo[2.2.0]hex-1(4)-ene: A Greatly Strained Alkene with Novel Reactivity," J. Am. Chem. Soc. 1996, 118, 9454-5.

Correa, R. A.; Lindner, P. E.; Lemal, D. M. "Novel Keto-Enol Systems," J. Am. Chem. Soc. 1994, 116, 10795-6.

Takenaka, N. E.; Hamlin, R.; Lemal, D. M. "Hexafluorobenzene Oxide and Hexafluorooxepin," J. Am. Chem. Soc. 1990, 112, 6715-6.

Rahman, M. M.; Lemal, D. M.; Dailey, W. P. "Negative Hyperconjugation.  The Rotation-Inversion Barrier in a-Fluoramines," J. Am. Chem. Soc. 1988, 110, 1964-6.

Dailey, W. P.; Lemal, D. M. “Perfluorotropilidene Valence Isomers and the Perfluorotropylium Ion,” J. Am. Chem. Soc. 1984, 106, 1169.

Wirth, D.; Lemal, D. M. “A Cyclobutadiene Oxide (Dewar Furan),” J. Am. Chem. Soc. 1982, 104, 847.

Laganis, E. D.; Lemal, D. M. “5H-Perfluoropentamethylcyclopentadiene, An Extraordinary Carbon Acid,” J. Am. Chem. Soc. 1980, 102, 6633.

 

Grayston, M. W.; Saunders, W. D.; Lemal, D. M. “Perfluorocyclopentadienone,” J. Am. Chem. Soc. 1980, 102, 413.

 

Ross, J. A.; Seiders, R. P.; Lemal, D. M. “An Extraordinarily Facile Sulfoxide Rearrangement,” J. Am. Chem. Soc. 1976, 98, 4325.

Gerace, M. J.; Lemal, D. M.; Ertl, H. “Tetrafluorocyclobutadiene,” J. Am. Chem. Soc. 1975, 97, 5584.

Lemal, D. M.; Chao, P. “Sulfur Monoxide Chemistry.  The Nature of SO from Thiirane Oxide and the Mechanism of its Reaction with Dienes,” J. Am. Chem. Soc. 1973, 95, 922.

Lemal, D. M. “Aminonitrenes (1,1-Diazenes),” in "Nitrenes," Lwowski, W., Ed., John Wiley and Sons, Inc., 1970.

Lemal, D. M.; Staros, J. M.; Austel, V. “Valence Isomers of (CCF3)6,” J. Am. Chem. Soc. 1969, 91, 3373.

Lemal, D. M.; Lokensgard, J. P. “Hexamethylprismane,” J. Am. Chem. Soc.  1966, 88, 5934.

Lemal, D. M.; McGregor, S. D. “Dienes from 3-Pyrrolines.  A Stereospecific Deamination,” J. Am. Chem. Soc. 1966, 88, 1335.

Lemal, D. M.; Lovald, R. A.; Kawano, K. I. “Tetraaminoethylenes:  The Question of Dissociation,” J. Am. Chem. Soc. 1964, 86, 2518.

Lemal, D. M.; Menger, F.; Clark, G. “Bicyclobutane,” J. Am. Chem. Soc. 1963, 85, 2529.

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