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Carl J. Lovely |
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Organic
Chemistry
Professor B.Sc., University of Birmingham (1987) Ph.D., University of Birmingham (1990) Postdoctoral Researcher: |
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Phone: 817-272-5446 FAX: 817-272-3808 E-mail: lovely@uta.edu Office: 204 CRB Personal Page |
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RESEARCH INTERESTS Heterocyclic Chemistry A long standing research program in the Lovely group centers on the development of new methods for the construction and elaboration of heterocyclic molecules. The total synthesis of the Martinella alkaloids 7 and 8 in both racemic (Scheme 1, 1®3®(±)-7) and non-racemic forms (Scheme 1, 4®6®(-)-7) exemplify our early endeavors.
Scheme 1 Current efforts are focused on the total synthesis of the oroidin family of pyrrole-imidazole alkaloids (e.g., 9-15, Figure 1), which have led to efficient methods for elaborating simple imidazoles into much more complex derivatives. Among the chemistry that we have developed is the Diels-Alder reaction of vinylimidazoles (inter- and intramolecular variants) and oxidative chemistry of tetrahydrobenzimidazoles. The combination of these transformations (Figure 2) has provided a concise approach to the spiro fused imidazoline fragments found in palau’amine (14) and massadine (15).
Figure 1: Oroidin and some oroidin-derived alkaloids.
Figure 2:
General approach to spiro fused core of palau’amine (14)
and massadine (15). Our efforts towards targets depicted in Figure 1, have provided the tools to develop synthetic approaches to a variety of other imidazole-containing natural products 21-24 (Figure 3).
Figure 3: Other imidazole-containing natural product targets.
Metal-Mediated
and Catalyzed Chemistry: In addition to these activities in heterocyclic chemistry, we have a collaborative program with Prof. Dias in the evaluation of novel catalysts based on fluorinated analogs of the well-known trispyrazolylborate (TP) ligands. We have discovered that a silver complex (where TP = (3,5-(CF3)2pyrazolyl)3BH act as efficient carbene transfer agents to C-Hal bonds, leading to the formation of halonium ylides (26 and 29), which then undergo rearrangement to provide polyfunctionalized adducts (Scheme 2).
Scheme 2 We also have an active interest in new applications of the Pauson-Khand reaction. In particular we have examined the utility of steric buttressing as a means to construct medium-sized rings, e.g., 32 and for the construction of congested cyclopentenones, e.g., 33 (Scheme 3). We are using the lessons learned in the course of these studies in a total synthesis of hamigeran B (34) and related molecules.
Scheme 3
Recent Publications: He, Y.; Moningka, R.; Lovely, C. J. Formal Total Synthesis of (± )-Martinellic Acid, Tetrahedron Lett. 2005, 46, 1251. Lovely, C. J.; Browning, R. G.;
Badarinarayana,
V.; Dias, H. V. R. He, Y.; Du, H.; Sivappa, R.; Lovely, C. J. New Methods for Imidazole Functionalization – From Imidazole to Marine Alkaloids, Synlett 2006, 965. Lovely, C. J.; He, Y.; Mahmud, H.; Moningka, R.; Dias, H. V. R. Cyclization Reactions of N-Acryloyl-2-Aminobenzaldehyde Derivatives: Formal Total Synthesis of Martinellic Acid, Tetrahedron 2006, 62, 8755. Krishnamoorthy, P.;
Sivappa, R.; Du,
H.; Lovely, C. J. Palladium-Catalyzed
Substitution Reactions of 4-Allylimidazole Derivatives, Tetrahedron
2006, 62,
10555 (Symposium-in-Print). Lovely, C. J.; He, Y.; Fenton, H. M.; Dias, H. V. R. Investigation of the Bromination of Tetrahydrobenzimidazoles, Heterocycles 2006, 70, 129. (Invited contribution for special issue in honor of Prof. Steven Weinreb.) Krishnamoorthy, P.; Browning, R.G.; Singh, S.; Sivappa, R.; Lovely, C. J.; Dias, H. V. R. Silver(I)-Catalyzed Preparation and [2,3]-Sigmatropic Rearrangement of Halonium Ylides Derived from Allyl and Propargyl Halides and Alkyl Diazoacetates, Chem. Commun. 2007, 731. Badarinarayana, V.; Lovely, C. J. Total Synthesis of (-)-Martinellic Acid, Tetrahedron Lett. 2007, 48, 2607. Lovely, C. J.; Du, H.; Sivappa, R.; Bhandari, M. R.; He, Y.; Dias, H. V. R. Preparation and Diels-Alder Chemistry of 4-Vinylimidazoles, J. Org. Chem. 2007, 72, 3741. Madu, C. E.; Seshadri, H.; Lovely, C. J. Steric buttressing in the Pauson-Khand reaction of aryl enynes, Tetrahedron 2007, 63, 5019. Madu, C. E.; Lovely, C. J. Steric Promotion of the Intramolecular Pauson-Khand Reactions of Aryl Enynes, Synlett 2007, 2011. Sivappa, R.; Koswatta, P.; Lovely, C. J. Oxidative Reactions of Tetrahydrobenzimidazole Derivatives with N-Sulfonyloxaziridines, Tetrahedron Lett. 2007, 48, 5771. Sivappa, R.; Hernandez, N. M.; He, Y.; Lovely, C. J. Studies Toward the Total Synthesis of Axinellamine and Massadine, Org. Lett. 2007, 9, 3861. Madu, C. E.; Lovely, C. J. A Pauson-Khand Approach to the Hamigerans, Org. Lett. 2007, 9, 4697. Chen, Y.; Ekanayake, V.; Lovely, C. J. Ring-Closing Metathesis Reactions of Imidazole Derivatives, Heterocycles 2007, 74, 873. Dias, H. V. R.; Lovely, C. J. Carbonyl and Ethylene Adducts of Coinage Metals Supported by Tris(pyrazolyl)borate Ligands and Silver Mediated Atom Transfer Reactions, Chem. Rev. 2008, 108, 3223. Lovely, C. J.; Badarinarayana, V. Synthetic Studies towards the Martinella Alkaloids, Curr. Org. Chem., 2008, 12, 1431. Koswatta, P. B.; Sivappa, R.; Dias, H. V. R.; Lovely, C. J. Total Synthesis of (±)-Calcaridine A and (±)-epi-Calcaridine A, Org. Lett., 2008, 10, 5055. Lovely, C. J.; Flores, J. A.; Meng, X.; Dias, H. V. R. Silver-Catalyzed C-H Insertion Reactions with Donor-Acceptor Diazoacetates, Synlett 2009, 129. Bhandari,
M. R.; Sivappa, R.; Lovely, C. J. Total
Synthesis of the Putative Structure of Nagelamide D, Koswatta,
P.; Lovely, C. J. Total
Synthesis of Preclathridine A and Clathridine A, Tetrahedron Lett.,
in press. Sivappa,
R.; Mukherjee, S.; Lovely, C. J. Studies
Toward the Total Synthesis of Oroidin Dimers, Org. Biomol. Chem., in
press. Flores, J. A.; Badarinarayana, V.; Singh, S.; Lovely, C. J.; Dias, H.
V. R. Synthesis and
Catalytic Activity of an Electron-Deficient Copper-Ethylene
Triazapentadienyl Complex, Dalton Trans., in press.
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Department of Chemistry and Biochemistry |
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