Benzo[a]carbazoles are rarely found in natural product and has unique position in biological active agents.1 Especially hydroxyl and amide derivatives of benzo[a]carabzole act as human Tpo receptor and antitumor agents respectively.2 Besides, some benzo[a]carbazoles used as molecular platforms for luminescent, hole-transporting and host material in organic light emitting diode.3 In general, transition metals are widely used for the synthesis of benzo[a]carbazole.4 Indeed, Fischer-Borsche is a classical method used for the preparation of benzo[a]carbazole.5 This involves the condensation of phenylhydrazine with tetralone followed by aromatization. However, aromatization of dihydrobenzo[a]carabzole is the challenging task. Such kind of transformations is carried out by heating the substrate with Pd/C in high boiling point solvents.6 Other organic based reagents capable of affecting the aromatization process are limited to quinone-derived reagent such as chloranil and DDQ.7 These kind of synthetic approaches required high temperature, loading of stoichiometric amounts of catalyst, long reaction time and low yield. For biological point of view, transition metals should be carefully removed from the final product. Also in the field of materials science, transition metallic impurities might influence the physical properties of the targeted material. To the best of our knowledge, very few reports are documented for the aromatization of dihydrobenzo[a]carbazoles to date. Therefore, development of rapid, efficient and conventional method for aromatization of dihydrobenzo[a]carbazoles is exceedingly desirable.
Over the last few decades, copper promoted transformations received considerable attention in organic syntheses.8 Moreover, copper...
... middle of paper ...
..., R. C. Larock, J. Org. Chem., 2006, 71, 1626; b) Kloeckner, U.; Finkbeiner, P.; Nachtsheim, B. J. J. Org. Chem., 2013, 78, 2751.
13. a) M. Geo, Y. D. Wu, C. Deng, W. M. Shu, D. X. Zhang, L. P. Cao, N. F. She, A. X. Wu, Org. Lett., 2010, 12, 4026; b) M. T. Barros, S. S. Dey, C. D. Maycock, P. Rodrigues, Chem. Comm., 2012, 48, 10901.
14. a) W. T. Eckenhoff, T. Pintauer, Cat. Reviews, 2010, 52, 1; b) Y. Chen, H. Xiang, C. Tan, Y. Xie, C. Yang, Tetrahedron, 2013, 19, 2714; c) Y. Yang, J. Yao, Y. Zhang, Org. lett., 2013, 15, 3206; d) P. Capdevielle, A. Lavigne, D. Sparfel, J. Baranne-Lafont, N. K. Cuong, M. Maumy, Tetrahedron Lett., 1990, 31, 3305; e) C. Dey, E. Evgeny, E. P. Kundig, Org. Biomol. Chem., 2013, 10.1039/C3OB41254G.
15. S. A. Weissman, D, Zewge, Tetrahedron 2005, 61, 7833.
16. Konda, S. G.; Humne, V. T.; Lokhande, P. D. Green Chem. 2011, 13, 2354.
Ramachandria, C. T., Subramanyan, N., Bar, K. J., Baker, G., & Yeragani, V. K. (n.d.).
This week’s lab was the third and final step in a multi-step synthesis reaction. The starting material of this week was benzil and 1,3- diphenylacetone was added along with a strong base, KOH, to form the product tetraphenylcyclopentadienone. The product was confirmed to be tetraphenylcyclopentadienone based of the color of the product, the IR spectrum, and the mechanism of the reaction. The product of the reaction was a dark purple/black color, which corresponds to literature colors of tetraphenylcyclopentadienone. The tetraphenylcyclopentadienone product was a deep purple/black because of its absorption of all light wavelengths. The conjugated aromatic rings in the product create a delocalized pi electron system and the electrons are excited
The complete experimental procedure is available in the General Chemistry Laboratory Manual for CSU Bakersfield, CHEM 213, pages 20-22, 24-25. Experimental data are recorded on the attached data pages.
Physical Chemistry Laboratory Manual, Physical Chemistry Laboratory, Department of Chemistry, University of Kentucky, Spring 2006.
Scibd. N.p. Web. 17 Mar 2014. Beller, Michele.
We thank the University of Oklahoma and the chemistry faculty for providing the space, instructions, and equipment for the development of this report and experiment.
The purpose of this lab was to to cycle solid copper through a series of chemical forms and return it to its original form. A specific quantity of copper undergo many types of reactions and went through its whole cycle, then returned to its solid copper to be weighted. We observed 5 chemical reactions involving copper which are: Redox reaction (which includes all chemical reactions in which atoms have their oxidation state changed), double displacement reaction, precipitation reaction, decomposition reaction, and single displacement reaction.
In this lab 4-tert-butylcyclohexanone is reduced by sodium borohydride (NaBH4) to produce the cis and trans isomers of 4-tert-butylcyclohexanol. Since the starting material is a ketone, NaBH4 is strong enough to perform a reduction and lithium aluminum hydride is not needed. NaBH4 can attack the carbonyl group at an equatorial (cis) or axial (trans) position, making this reaction stereoselective. After the ketone is reduced by the metal-hydride, hydrochloric acid adds a proton to the negatively charged oxygen to make a hydroxyl group. The trans isomer is more abundant than the cis based on the results found in the experiment and the fact that the trans isomer is more stable; due to having the largest functional groups in equatorial positions.
yield of the pure product was determined to be 95.42%. PURPOSE The purpose of this lab was to perform an electro-philic aromatic substitution and determine the identity of the major product. TLC was used to detect unreacted starting material or isomeric products present in the reaction mixture. RESULTS The theoretical yield of the m-nitrobenzoate was determined to be 4.59 grams.
All calculations and simulations for our experiment were performed utilizing Spartan Student v7.2.7 software through different 2 computational methods (Hartree-Fock and EDF2) and 2 corresponding basis sets (6-31G*and 6-311+G**). In terms of accuracy, EDF2 (which is based on Electron Density Functional Theory) was the more accurate of the two, and the reasoning for this is simple. Hartree-Fock has to make many approximations for its calculation because it is based on wavefunctions rather that electron density functions like EDF2 that take into account electron-electron interactions. Hartree-Fock mostly ignores these interactions by producing a system wavefunction from many separate 1 electron spin wavefunctions. This method is normally a basis point for more advanced
Schreuder, Jolanda A. H.; Roelen, Corné A. M.; van Zweeden, Nely F.; Jongsma, Dianne; van der Klink, Jac J. L.; Groothoff, Johan W.
Thickett, Geoffrey. Chemistry 2: HSC course. N/A ed. Vol. 1. Milton: John Wiley & Sons Australia, 2006. 94-108. 1 vols. Print.
David and John Free. (26 Nov 2006). MadSci Network: Chemistry. Retrieved on March 6, 2011, from http://www.madsci.org/posts/archives/2007-02/1171045656.Ch.r.html
1. Brown, Theodore L., H. Eugene LeMay Jr., Bruce E. Bursten. Chemistry: The Central Science. Upper Saddle River: Prentice Hall, 2000.
Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/