Physical Sciences and Mathematics Commons^™

Ruthenium Hydride Catalyzed Silylvinylation Of Alkynes, Robert J. Wilson

Dissertations - ALL

The intermolecular ruthenium hydride catalyzed coupling of internal alkynes with subsequent insertion of olefin acceptors is described. This approach utilizes a vinyl silicon tether to provide complete regiocontrol, a stereoselective anti-exo-dig cyclization which affords a tetrasubstituted olefin with a new vinylsilane, and a highly functionalized Z,E diene motif. Subsequent studies for a highly selective intramolecular trans-silylvinylation of internal alkynes catalyzed by RuHCl(CO)(SIMes)(PPh3) is reported. The use of methyl vinyl ketone as an additive increased the efficiency of this transformation. This process was expanded upon using ethylene gas as an additive and provides a net 5-exo-dig trans-silylvinylation of internal alkynes. Ethylene …

Asymmetric Synthesis Of All-Carbon Α-Aryl Quaternary Carbonyl Compounds By Palladium-Catalyzed Asymmetric Allylic Alkylation (Pd-Aaa) And Their Application To The Synthesis Of Biologically Important 3,3′-Disubstituted Oxindole And Α-Disubstituted Quaternary Β-Lactone Frameworks, Md. Sharif Al Asad

Theses and Dissertations

The development of catalytic, enantioselective methods for the construction of all-carbon quaternary stereocenters is an outstanding achievement in the recent history of organic chemistry. The palladium-catalyzed asymmetric allylic alkylation (Pd-AAA) reaction has played a key role in creating such stereocenters and has allowed researchers to synthesize a vast number of biologically potent natural products. However, synthetic methodologies to access compounds containing α-aryl groups to the quaternary carbon stereocenters are still rare. The increasing appearance of these all-carbon α-aryl quaternary stereocenters in a growing number of biologically active natural products and pharmaceutical agents creates a pressing need for the ability to …

Immobilization Of Scandium And Other Chemical Elements In Systems With Aquatic Macrophyte, S. A. Ostroumov, M. E. Johnson, Julian Tyson, B. Xing

Chemistry Department Faculty Publication Series

No abstract provided.

Development Of Improved Methodologies Toward The Formation Of C-C And C-N Bonds, Ijaz Ahmed

Dissertations - ALL

Organometallic chemistry provides valuable tools for the formation of carbon-carbon and carbon-heteroatom bonds that would otherwise require multiple steps and resources to achieve through conventional methods. Studies toward the regioselective and stereoselective formation these types of bonds using different organometallic methods will be presented. Three focal areas have been studied: C-N bond formation, C-H borylation, and silylvinylation of alkynes.

In Chapter 1, palladium-catalyzed amidation has been used to effectively form C-N bonds toward the synthesis of valuable imidazo[4,5-b]pyridines and imidazo[4,5-c]pyridines. The reaction conditions are tolerable for a variety of N-substituted-3-amino-2-chloropyridines. All current routes to expand the substrate scope in regards …

Contribution Of Heterobifunctional Ligands To Transition Metal-Catalysed C--C Coupling Reactions, Agnes Labande, Eric Deydier, Eric Manoury, Jean-Claude Daran, Catherine Audin, Rinaldo Poli

Turkish Journal of Chemistry

In this account the authors' latest results in C-C coupling catalysis are reviewed. First, an efficient catalytic system for the Kumada-Tamao-Corriu coupling reaction based on NHC-phosphine (NHC = N-heterocyclic carbene) nickel complexes is presented. Then the use of palladium complexes of chiral ferrocenyl NHC-phosphines in the asymmetric Suzuki-Miyaura coupling reaction is reported. High catalytic activities and moderate enantioselectivities (ee up to 46%) were obtained. Chiral ferrocenyl phosphine-ethers were also tested in the asymmetric Suzuki-Miyaura reaction yielding good activities and moderate enantioselectivities (ee up to 37%). Finally, the original synthesis of a ferrocenyl rhodium(III) complex and its successful use as catalyst …

Palladium-Catalyzed Ligand-Free And Efficient Suzuki--Miyaura Reaction Of $N$-Methyliminodiacetic Acid Boronates In Water, Chun Liu, Xinmin Li, Xinnan Wang, Jieshan Qiu

Turkish Journal of Chemistry

A green and efficient protocol has been developed for the Pd(OAc)$_{2}$-catalyzed ligand-free Suzuki--Miyaura reaction of $N$-methyliminodiacetic acid (MIDA) boronates in water. In the presence of Pd(OAc)$_{2}$ as a catalyst and ($i$-Pr)$_{2}$NH as a base, the cross-coupling reactions of aryl bromides with aryl MIDA boronates proceeded smoothly in water without any surfactant, and various functional groups were tolerated under the optimized conditions.

Synthesis Of New Thiol-Derivatized Aminophosphines And Their Catalytic Activities In C--C Coupling Reactions, Nermi̇n Bi̇ri̇ci̇k, Nermi̇n Meri̇ç, Cezmi̇ Kayan, Zeynep Özgen, Sevi̇l Şeker Azi̇zoğlu, Bahatti̇n Gümgüm

Turkish Journal of Chemistry

A series of new aminophosphines [Ph$_{2}$PHN-C$_{6}$H$_{4}$-R, where R = $o$-SH (4a), $m$-SH (4b) or $p$-SH (4c)] were readily synthesized from cheap starting materials by the phosphorylation reaction of $o$, $m$, and $p$-aminothiophenols with Ph$_{2}$PCl in the presence of triethyl amine. The new compounds were characterized by NMR and IR spectroscopy and microanalysis. In addition, aminophosphine ligands-palladium systems were investigated as precatalysts in C-C coupling reactions. Compounds 4b and 4c were proved to be excellent catalysts for Suzuki and Heck cross-coupling reactions.

New Pd(Ii) And Pt(Ii)-Diaminophosphine Complexes Bearing Cyclohexyl Or Isopropyl Moiety: Use Of Pd(Ii) Complexes As Precatalyst In Mizoroki--Heck And Suzuki--Miyaura Cross-Coupling Reactions, Murat Aydemi̇r, Feyyaz Durap, Akin Baysal

Turkish Journal of Chemistry

Two new diaminophosphine ligands, $N$,$N$'-bis(dicyclohexylphosphino)-2-(aminomethyl)aniline (1) and $N$,$N$'-bis(diisopropylphosphino)-2-(aminomethyl)aniline (2) were synthesized by the reaction of 2-(aminomethyl)aniline with two equivalents of Cy$_{2}$PCl or (iPr)$_{2}$PCl, respectively. The reactions of 1 and 2 with MCl$_{2}$(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) yield complexes [cis-Pd(L$_{2}$PNHC$_{6}$H$_{4}$CH$_{2}$NHPL$_{2})$Cl$_{2}$] (L = Cy 3, iPr 4) and [cis-Pt(L$_{2}$PNHC$_{6}$H$_{4}$CH$_{2}$NHPL$_{2})$Cl$_{2}$] (L = Cy 5, iPr 6), respectively. The catalytic activity of the palladium complexes was investigated in the Suzuki-Miyaura cross-coupling reaction in the presence of Cs$_{2}$CO$_{3}$ as a base. The palladium complexes were also found to be highly active catalysts in the Mizoroki-Heck reaction.

Substituted 2-(2''-Pyridyl)Benzimidazole Palladium(Ii) Complexes As An Efficient Catalytic System For Suzuki--Miyaura Cross-Coupling Reactions, Mahmut Ulusoy, Nurdal Öncel, Emi̇ne Aytar

Turkish Journal of Chemistry

A new series of $N,N$-type 2-(2'-pyridyl)benzimidazole ligands (2A$_{\mathbf{1}}$, 2A$_{\mathbf{2}}$, 3B$_{\mathbf{1}}$, 3B$_{\mathbf{2}}$, 3B$_{\mathbf{3}}$, and 4C$_{\mathbf{1}})$ and their Pd(II) complexes (5A$_{\mathbf{1}}$, 5A$_{\mathbf{2}}$, 6B$_{\mathbf{1}}$, 6B$_{\mathbf{2}}$, 6B$_{\mathbf{3}}$, and 7C$_{\mathbf{1}})$ were prepared and characterized by conventional spectroscopic methods and elemental analyses. The incorporation of $N$-coordinated benzimidazole complexes of palladium gave high catalytic activity in the Suzuki-Miyaura coupling of aryl halides substrates. After determining the best active catalyst as 5A$_{\mathbf{1}}$, bearing the mesityl substituent on the benzimidazole ring with the Pd(II) ion, optimization studies were carried out via changing the substrate, base, time, atmosphere, and the effect of water. The DMF:H$_{2}$O (4/1) and Cs$_{2}$CO$_{3}$ as base …

Palladium-Catalyzed C8-Selective C-H Arylation Of Quinoline N-Oxides: Insights Into The Electronic, Steric And Solvation Effects On The Site-Selectivity By Mechanistic And Dft Computational Studies, David E. Stephens, Johant Lakey-Beitia, Abdurrahman Atesin, Tülay A. Ateşin, Gabriel Chavez, Hadi D. Arman, Oleg V. Larionov

Chemistry Faculty Publications and Presentations

We report herein a palladium-catalyzed C-H arylation of quinoline N-oxides that proceeds with high selectivity in favor of the C8-isomer. This site-selectivity is unusual for palladium, since all of the hitherto described methods of palladium-catalyzed C-H functionalization of quinoline N-oxides are highly C2-selective. The reaction exhibits a broad synthetic scope with respect to quinoline N-oxides and iodoarenes and can be significantly accelerated to sub-hour reaction times under microwave irradiation. The C8-arylation method can be carried out on gram scale and has excellent functional group tolerance. Mechanistic and Density Functional Theory (DFT) computational studies provide evidence for the …

Cross Coupling Reactions Catalyzed By (Nhc)Pd(Ii) Complexes, Nevi̇n Gürbüz, Emi̇ne Özge Karaca, İsmai̇l Özdemi̇r, Beki̇r Çeti̇nkaya

Turkish Journal of Chemistry

This review is focused on new developments reported during the last 3 years concerning the catalytic performances of in situ formed or preformed NHC--Pd(II) complexes (NHC: $N$-heterocyclic carbene) for cross-coupling reactions such as Heck--Mizoraki (often shortened to the Heck reaction), Kumada, Negishi, Suzuki--Miyaura (often shortened to the Suzuki reaction), Sonogashira and Hiyama couplings, and the Buchwald--Hartwig aminations, which are extremely powerful in the formation of C--C and C--heteroatom bonds. Due to the great number of publications and limited space here, we made a special attempt to compile the relevant data in tables, which we hope will serve as a guide …

Palladium-Catalysed Suzuki--Miyaura Cross-Coupling With Imidazolylidene Ligands Substituted By Crowded Resorcinarenyl And Calixarenyl Units, Neslihan Sahin, David Semeril, Eric Brenner, Dominique Matt, Cemal Kaya, Loic Toupet

Turkish Journal of Chemistry

Two $N$-heterocyclic carbene (NHC) palladium complexes of formula [PdBr$_{2}$(NHC)(pyridine)] in which the carbenic ring is flanked by sterically crowded cavitand substituents were prepared from appropriate imidazolium salts bearing either two resorcinarene or a combination of resorcinarene and calixarene fragments. Both complexes displayed high stability and good activities in the cross-coupling of aryl bromides with phenyl boronic acid. One of the imidazolium salts was characterised by an X-ray diffraction study.

The Synthesis Of 1,3-Dialkyl-4-Methylimidazolinium Salts And Their Application In Palladium Catalyzed Heck Coupling Reactions, Murat Yi̇ği̇t, Güli̇n Bayam, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r

Turkish Journal of Chemistry

Seven novel 1,3-dialkyl-4-methylimidazolinium chloride salts 3a--g were prepared as precursors of N-heterocyclic carbenes by reacting N,N'-alkyl-1,2-diaminopropane, triethyl orthoformate, and ammonium chloride. The salts were characterized spectroscopically. The in situ prepared palladium complexes derived from the imidazolinium salts and palladium acetate were used as catalyst in Heck coupling reactions between aryl bromides and styrene. The corresponding Heck products were obtained in good yields.

Studies Toward The Total Synthesis Of Subincanadine E, Corinne Marie Sadlowski

Graduate College Dissertations and Theses

Progress towards a concise total synthesis of subincanadine E is reported. This natural product was first isolated from the Picralima nitida cell suspension culture line in 1982 under the name pericine and later in 2002 from Aspidosperma subincanum as subincanadine E. It is the most potent compound of its class with in vitro cytotoxicity against both murine lymphoma L1210 and human epidermoid carcinoma KB cells (LD50, 0.3 ug/mL and 4.4 ug/mL, respectively) and was found to be six times more potent than codeine as an opiate agonist in a 3H-naloxone binding study (IC50, 0.6 umol/L).

The first-generation synthesis produced an …