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Mesoporous silica-functionalized dual Brønsted acidic ionic liquid as an efficient catalyst for thioacetalization of carbonyl compounds in water
, Article Catalysis Communications ; Volume 41 , 2013 , Pages 96-100 ; 15667367 (ISSN) ; Dizicheh, Z. B ; Hashemi, M. M ; Sharif University of Technology
2013
Abstract
A novel silica-functionalized dual Brønsted acidic ionic liquid (ionic liquid with two Brønsted acidic species) has been reported as a highly efficient catalyst for thioacetalization of carbonyl compounds. The reaction was efficiently performed in water as an environmentally benign solvent with good to high yields. Thermal gravimetric analysis showed that the catalyst is stable at least up to 350 C. Furthermore, the catalyst can be recycled and reused for six runs of reaction without appreciable loss of activity. The structure of the catalyst is modelized to gain more realistic structural insight about the functionalized ionic liquid
Immobilization Heavy Metal Ions and Nanoparticles (Au, Cu, Pd) on Biopolymers and Their Catalytic Activities in the Organic Reactions
, Ph.D. Dissertation Sharif University of Technology ; Pourjavadi, Ali (Supervisor)
Abstract
Recently, biopolymers such as alginate, cellulose, chitosan, gelatine, starch and wool have been used as supports for catalytic applications. Several interesting features of the biopolymers for example, bio-degradable, environmentally safe, high sorption capacity, physical and chemical versatility make them attractive to use as supports. This study, the four functionalized biopolymer-based composites were designed and synthesized as well as heterogeneous catalysts used in the synthesis of 1,2,3-triazoles, oxidation of alcohol, reduction of nitroarenes and carbon-carbon coupling reactions.A novel cellulose supported copper NHC complex has been prepared by the reaction of cellulose supported...
Preparation of Nitrogen Rich Magnetic Nanocomposite for Immobilization of Transition Metals and Investigation of their Catalytic Activity in Organic Reactions
, Ph.D. Dissertation Sharif University of Technology ; Pourjavadi, Ali (Supervisor) ; Matloubi, Firouz (Supervisor)
Abstract
In this thesis, heterogeneous magnetic catalysts immobilize have been designed and synthesized in a triazine polymer support. Triazine polymeric support increases the amount of nitrogen due to their high levels of nitrogen, which in turn reduces the amount of catalyst consumed and reduces metal waste and increases catalyst activate. Melamine and TCT from the triazine family are used because of the ability to form hydrogen bonds, chelate with metals, and the interaction of π-π as an appropriate ligand for stabilizing metals on substrates. In this thesis, various nitrogen-rich polymers based on triazines in the presence of magnetic nanoparticles coated with silica and their compositions with...
Deep eutectic solvents: Cutting-edge applications in cross-coupling reactions
, Article Green Chemistry ; Volume 22, Issue 12 , 2020 , Pages 3668-3692 ; Afshari, R ; Ramón, D. J ; Varma, R. S ; Sharif University of Technology
Royal Society of Chemistry
2020
Abstract
Deep eutectic solvents (DESs), surmised as "the organic reaction medium of the century", have reverberated a new symphony throughout the present green millennium. A brief historical account of the DES systems and their physicochemical properties as task-specific and designer solvents for cross-coupling reactions are appraised including the hole theory that explains the underlying mechanistic pathway for this emerging neoteric medium. The insights into cross-coupling reactions and their applications are included, highlighting the significant achievements pertaining to the dual role of DESs as a solvent and catalyst. In addition, popular "name-reactions"for the carbon-carbon and...
Cloning and Production of the Flavin Reductase Enzyme in Order to Perform Organic Reaction and Synthesis of Cation Exchange Column for Protein Purification
, M.Sc. Thesis Sharif University of Technology ; Kalhor, Hamid Reza (Supervisor)
Abstract
The reductase enzymes perform an important function in the cell. These enzymes are usually coupled with other enzymes and participate in reactions such as halogenation, reduction of alkene, and carboxylic acids. These reactions are carried out by reproducing cofactors such as FADH2 and NAD+; however, there is no evidence that this enzyme alone can perform an organic reaction. In this work, we aim to examine whether recombinant flavin reductase can carry out organic reactions. In order to amplify the flavin reductase enzyme gene from the E. coli genome by PCR (Polymerase Chain Reaction) method, two synthetic primers were designed; The forward primer of the gene contained a cleavage site for...
Investigate Kinetic Parameters of L-Asparaginase Ii as Well as its Performance in Organic Reactions and Modifying the Enzyme Through Directed Evolution for Carrying Out Promiscuous Reactions
, M.Sc. Thesis Sharif University of Technology ; Kalhor, Hamid Reza (Supervisor)
Abstract
L-asparaginase II is an amidohydrolase which hydrolyzes L-asparagine to furnish L-aspartic acid and ammonia. The enzyme has played an important role for 40 years in treating cancer in persons with juvenile leukemias or lymphomas. Furthermore, the enzyme has become important in food industries and biosensors technology.In this study, the expression of recombinant L-asparaginase II in E. Coli was optimized and the purification of this enzyme from growth culture was carried out with nickel-charged affinity resin. Afterwards, the activity, and kinetic parameters of purified recombinant L-asparaginase II including Km, kcat, Vmax, and enzyme efficiency were measured.In the next step, random...
Synthesis and Application of Transition Metal Spinels (Cu, Ni, Co, Pd and Fe) as a Catalyst in Organic Reactions
, Ph.D. Dissertation Sharif University of Technology ; Matloubi Moghaddam, Firouz (Supervisor)
Abstract
In the first section, due to the important role of nanocatalysts in different fields of chemistry, magnetic metal ferrite nanoparticles were synthesized. Ferrite nanoparticles were synthesized using co-precipitation method and were characterized. Then, these nanoparticles were applied as catalyst system for one-pot β-ketophosphonates and thiophosphate synthesis.This is a green and efficient route for S-P and C-P bond construction using copper ferrite nanoparticles as catalyst. The application of a highly active recyclable heterogeneous nanocopper ferrite catalyst for the oxyphosphorylation reaction of various alkenes was conducted under ligand-free conditions, in acetonitrile as solvent at...
Polyethylene glycol (PEG) as a green solvent for carbon-carbon bond formation reactions
, Article Journal of Molecular Liquids ; Volume 207 , 2015 , Pages 73-79 ; 01677322 (ISSN) ; Mahmoodi Hashemi, M ; Sharif University of Technology
Abstract
In recent years, polyethylene glycol (PEG) has attracted special attention as a green and inexpensive solvent in various chemical transformations. The current critical review deals with breakthrough achievements for the applications of PEG as an alternative reaction media well-known coupling reactions such as Suzuki, Heck, Stille, Sonogashira, Hiyama and some challenging organic reactions for carbon-carbon bond formation
Influence of the hydrogen bonding on the basicity of selected macrocyclic amines
, Article Journal of Physical Organic Chemistry ; Volume 25, Issue 9 , 2012 , Pages 803-810 ; 08943230 (ISSN) ; Shakourian Fard, M ; Fattahi, A ; Sharif University of Technology
2012
Abstract
The optimized minimum-energy geometries of different macrocyclic amines and their protonated structures were determined by using ab initio and density functional theory (DFT) calculations. All the gas phase optimizations and energy calculations were performed at the DFT/B3LYP/6-311++G(d,p) level of theory. The HF/6-31 + G(d,p) level was used for all single point calculations in the solution phase. Geometry optimizations indicate that the most stable structures are stabilized by intramolecular hydrogen bonds. The proton affinity (PA) of macrocyclic amines is controlled by the strength of intramolecular hydrogen bonds of macrocyclic amines. These hydrogen bonds strongly influence the basicity...