Direct transition metal-catalyzed functionalization of heteroaromatic compounds.

Department of Chemistry, University of Illinois at Chicago, 845 West Taylor St., Chicago, Illinois 60607-7061, USA.
Chemical Society Reviews (Impact Factor: 24.89). 08/2007; 36(7):1173-93. DOI: 10.1039/b606984n
Source: PubMed

ABSTRACT During the last two decades there has been considerable growth in the development of catalytic reactions capable of activating unreactive C-H bonds. These methods allow for the synthesis of complex molecules from easily available and cheaper precursors in a fewer number of steps. Naturally, the development of C-H activation methods for direct functionalization of heterocyclic molecules, invaluable building blocks for pharmaceutical and synthetic chemistry and material science, has received substantial attention as well. This critical review summarizes the progress made in this field until November 2006 (117 references).

  • [Show abstract] [Hide abstract]
    ABSTRACT: We describe the controlled and regioselective transition-metal-catalyzed C-H bond arylation of protected l-histidine with aryl halides as the coupling partner. Using this approach, a large number of C-2 arylated l-histidines have been synthesized with diverse substitutions bearing electron-donating and electron-withdrawing groups, in good to excellent yields. These synthetic amino acids possessing dual hydrophobic-hydrophilic character are important synthons of bioactive peptidomimetics, which are imperative potent inhibitors of Cryptococcus neoformans.
    Organic & Biomolecular Chemistry 04/2014; 12:3792-3796. · 3.57 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The dehydrogenative coupling of imidazo[1,2-a]pyridine derivative has been achieved for the first time. In cases in which the most-electron-rich position of the electron-excessive heterocycle was blocked by a naphthalen-1-yl substituent, neither oxidative aromatic coupling nor reaction under Scholl conditions enabled the fusion of the rings. The only method that converted the substrate into the corresponding imidazo[5,1,2-de]naphtho[1,8-ab]quinolizine was coupling in the presence of potassium in anhydrous toluene. Moreover, we discovered new, excellent conditions for this anion-radical coupling reaction, which employed dry O2 from the start in the reaction mixture. This method afforded vertically fused imidazo[1,2-a]pyridine in 63 % yield. Interestingly, whereas the fluorescence quantum yield (Φfl) of compound 3, despite the freedom of rotation, was close to 50 %, the Φfl value of flat naphthalene-imidazo[1,2-a]pyridine was only 5 %. Detailed analysis of this compound by using DFT calculations and a low-temperature Shpol′skii matrix revealed phosphorescence emission, thus indicating that efficient intersystem-crossing from the lowest-excited S1 level to the triplet manifold was the competing process with fluorescence.Po raz pierwszy otrzymano nowy typ związku heterocyklicznego - imidazo[1,2-a]pirydynę sprzężoną w pozycjach 3 i 5 z naftalenem. Udowodniono, że spośród wszystkich metod wewnątrzcząsteczkowego odwodornienia tylko sprzęganie z wytworzeniem aniono-rodników prowadzi do oczekiwanego produktu. Opracowano przy tym nowe warunki prowadzenia tej reakcji, w których suchy tlen jest obecny od początku w układzie reakcyjnym. Dokładne zbadanie właściwości optyczne obu związków zarówno w roztworze jak i w matrycach Szpolskiego oraz poprzez obliczenia kwantowo-mechaniczne wykazały, że za niską wydajność kwantową fluorescencji odpowiedzialne jest przejście międzysystemowe na nisko leżący stan trypletowy.
    Chemistry - An Asian Journal 05/2014; · 4.57 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The past decades have seen an explosive growth in the application of density functional theory (DFT) methods to molecular systems that are of interest in a variety of scientific fields. Owing to its balanced accuracy and efficiency, DFT plays particularly useful roles in the theoretical investigation of large molecules. Even for biological molecules such as proteins, DFT finds application in the form of, e.g., hybrid quantum mechanics and molecular mechanics (QM/MM), in which DFT may be used as a QM method to describe a higher prioritized region in the system, while a MM force field may be used to describe remaining atoms. Iron-containing molecules are particularly important targets of DFT calculations. From the viewpoint of chemistry, this is mainly because iron is abundant on earth, iron plays powerful (and often enigmatic) roles in enzyme catalysis, and iron thus has the great potential for biomimetic catalysis of chemically difficult transformations. In this paper, we present a brief overview of several recent applications of DFT to iron-containing non-heme synthetic complexes, heme-type cytochrome P450 enzymes, and non-heme iron enzymes, all of which are of particular interest in the field of bioinorganic chemistry. Emphasis will be placed on our own work.
    Frontiers in Chemistry 01/2014; 2:14.


1 Download
Available from