Karl De Jesus
Associate Professor of Chemistry
Ph.D. Organic Chemistry,
University of Wisconsin, Madison -- 1986
|Research Area:||Synthetic organic chemistry, organosilane chemistry, isotopic labeling|
|Student Experience required for research:||Students must have taken Chem 111, 112, 301, and 303 as a minimum. Preference is given to those with Chem 302, 304 and a long-term commitment to being in the research group.|
|Student Experience gained from research:||Inert atmosphere techniques, extraction and distillation techniques, and purification techniques such as preparatory thin layer and flash chromatography. Instrumental analysis (GC, GC-MS, IR, and NMR) so students will gain hands on experience on each of these instruments. Students are very encouraged to present their results at meetings and symposia thus gaining experience in presentation preparation and public speaking.|
|Ideal Preparation for:||Past students have gained scientific analysis skills that have served them well in a variety of industries including the semiconductor industry. The skills are most directly applicable to industrial positions involving spectroscopic analysis or materials preparations. In the past these have included the pharmaceutical, chemical manufacture, and polymer industries. Moreover, the biological and labeling components are good training for biochemical or medicinal research.|
Work in this laboratory spans a wide range of organic synthetic projects. Projects revolve around three themes: organosilane chemistry, development of chiral transfer reagents and auxiliaries, and the preparation of biologically and medicinally important compounds. Organosilane projects involve development of methods for the preparation of chiral silanes as well as their mediation of organic reactions to produce enantiospecific products. These have high potential application to the synthesis of chiral organic compounds since silanes are common intermediates in many modern organic reactions.
Our chiral transfer reagent studies involve the use of chiral, bicyclic amines. These amines are protonated/deuterated to yield a source of chiral protons/deuteriums for use in chiral protonations or deuterations of enolates. There is a great need for enantiospecifically deuterated compounds, specially in the spectrometric study of nucleic acids. This method would provide a source for these compounds. Other applications of these amines are currently being explored which might facilitate the stereospecific introduction of nucleophilic groups to aldedydes and ketones. These in turn, would make available a wide range of alcohols that are necessary precursors in the synthesis of chiral drugs. In addition, a number of chiral polymers are being studied with potential application in the synthesis of commercially important chiral compounds.
Our laboratory collaborates with a number of biological and medicinal laboratories that require noncommercial substrates in order to perform their studies. We prepare these compounds for them, some of them isotopically labeled. Among the latter is the synthesis of 13C,15N-labeled thalidomide. This teratogenic compound has recently been found to be effective in the treatment of leprous lesions and some tumors, yet its mode of action has not been elucidated. Our labeled thalidomide will facilitate some studies on its mode of action. Other compounds being synthesized involve fluorescent biological probes. These include heme-like compounds that could be used as probes for iron-containing enzymes and substituted phenylacetylenes which are currently being studied as probes for monooxidase containing bacteria. The latter, when indigenous, are important for performing environmental clean up of aromatic and halogenated organic wastes.
"Nucleoside Intermediates in Blasticidin S Biosynthesis Identified by the In Vivo Use of Enzyme Inhibitors," S.J. Gould*, J. Guo, K. De Jesus, A. Geitmann, Canadian Journal of Chemistry, 72(1), 6-11, 1994.
"A Problem Based Approach to Organic Chemistry," K. De Jesus, Journal of Chemical Education, 72(3), 224-226, 1995.
"The Mechanism of NaBH4 Addition to Aldehydes - Labeling Experiement," R.K. Robinson, K. De Jesus*, Journal of Chemical Education, 75(3), 264-266, 1996.
"The Selective Monohalogenation of Dihydro and Trihydrosilanes", P.B. Gensle, B.C. Gruber, J.T. Jarvis, A.Slaitas, SeneMarie De Jesus, K. De Jesus", Microchemical Journal, 55, 222-234, 1997.
"Determining the Solution State Orientation of a Ti Enolate via Stable Isotope Labeling, NMR Spectroscopy, and Modeling Studies," Kimball, David B.; Michalczyk, Ryszard; Moody, Eddie; Ollivault-Shiflett, Morgane; De Jesus, Karl; Silks, Louis A. Pete, Journal of the American Chemical Society, 125(48), 14666-14667, 2003.
"Activity-dependent Fluorescent Labeling of Bacterial Cells Expressing the TOL Pathway," S.R. Clingenpeel, W.K. Keener, C.R. Keller, K. De Jesus, M.H. Howard, and M.E. Watwood, Journal of Microbiological Methods, 60, 41-46, 2005.