Organic Chemistry Commons^™

Synthesis And Application Of Atp Analogs For Phosphorylation-Dependent Kinase-Substrate Crosslinking, Satish Kumar Garre Venkata Raghavendra

Wayne State University Dissertations

Phosphorylation is an important post-translational modification that plays a key role in a variety of signaling cascades and cellular functions. Kinases phosphorylate protein substrates in a highly regulated manner and are promiscuous. Understanding kinase-substrate specificity has been challenging and there is a need for new chemical tools. To this end we developed -phosphate modified ATP photocrosslinking analogs ATP-ArN3 and ATP-BP, that crosslink substrate and kinase in a phosphorylation dependent manner. We have successfully demonstrated that ATP-ArN3 and ATP-BP can be used with natural kinase and substrates using cell lysates in vitro. We used our approach to identify novel kinases of …

1. Chromium(0)- Promoted Higher Order Cycloaddition Reactions: Studies Toward The Total Synthesis Of The Cyclocitrinols And Echinopines A And B 2. Total Synthesis Of (±)-Debromoflustramine B Via [4+1] Cyclization Of An Indole Isocyanate And A Bis(Alkylthio)Carbene, Saptarshi De

Wayne State University Dissertations

A facile and short stereoselective synthesis of the functionalized tetracyclic core structure of the cyclocitrinols, a family of unusual C25 steroid isomers, has been accomplished. The key structural unit, the bicyclo[4.4.1]A/B ring system, was constructed by a regioselective Cr(0)-promoted [6π + 4π] photochemical cycloaddition reaction.

A Bronsted acid catalyzed rearrangement of the 11-trimethylsilyl-tetracyclo[8.1.0.03,7.04,11]undeca-5,8-diene ring system to the unusual homotriquinacene ring system. The trimethylsilyl substitution on the cyclopropane moiety was found to be crucial for the rapid transformation which is believed to proceed via carbocation intermediates.

A short concise formal synthesis of Echinopines A and B is reported. The key [5.5.7] …

Synthesis Of Oligosaccharide Mimetics By The Desulfurative Rearrangement Of Allylic Disulfides And Stereoelectronic Influence Of C-O Bonds On C- And O-Glycosylation, Myriame Moume-Pymbock

Wayne State University Dissertations

This dissertation focuses on two different problems. The first part of this manuscript presents the application of a novel methodology to access the synthesis of oligosaccharide mimetics while the second part focuses on the study of the stereoelectronic effects of proximal C-O bonds in C- and O-glycosylation reactions.

The first chapter provides a brief overview of the important roles that oligosaccharides and glycoconjugates play in biological processes and sets out the major advances that have been made in the past few decades in the synthesis of such complex structures while bringing out the ongoing challenges and the limitations that impede …

Synthesis Of N-Acetyl And C-Tert-Butyl Natural Amino Acid Substrates That Mimic Residues Of Polypeptides And Their Reactivity With [Feiv(O)(N4py)]2+: Kinetic And Mechanistic Investigations, Ashley Ann Campanali

Wayne State University Dissertations

This dissertation is divided into two chapters, the first chapter includes an introduction to reactive oxygen species and their reactions with proteins. The introduction also covers metal-based oxidants, including both heme and non-heme enzymes that activate dioxygen as well as complexes that mimic these enzymes. The work discussed in chapter one concerns the synthesis of amino acid substrates that mimic amino acid residues. Substrates synthesized were derived from Gln, Asn, Ile, Cys and Tyr. Once synthesized, these substrates were reacted with [FeIV(O)(N4Py)]2+ under pseudo-first order conditions. The mechanisms for the reactions of the most reactive substrates were investigated. Electron-transfer proton-transfer …

Development Of Chemical Inducers Of Dimerization For Screening Competitive Histone Deactelyase Inhibitors, Emily Lynn Aubie

Wayne State University Dissertations

Histone Deacetylase (HDAC) proteins are transcriptional regulators that affect histone proteins, which are involved in packaging of DNA into chromosomes. HDACs have been linked to the proliferation of cancer through their role in transcriptional regulation. Due to these findings, HDAC inhibitors have been explored as anti-cancer agents. Several HDAC inhibitors are currently in various stages of clinical trials, and the inhibitor suberoyl anilide hydroxamic acid (SAHA) has been FDA approved for treatment of cutaneous T-Cell lymphoma. Currently, most of the known HDAC inhibitors are non-selective, which causes non-specific binding to the active sites of all HDAC isoforms, including those not …

Chemical Synthesis Of Peptides And Peptide Thioesters, Indrajeet Sharma

Wayne State University Dissertations

This dissertation describes investigations toward the development of a new chemistry for the block synthesis of peptides and peptidyl thioesters. A direct approach for the Fmoc-SPPS of peptidyl thioesters is also delineated in this thesis.

In the first part of chapter one, the difficulty and importance of chemical synthesis of peptides is explained, and a brief survey of available methods is given. The second part of chapter one presents the challenges inherent in the synthesis of peptidyl thioesters by Fmoc-SPPS.

The second chapter outlines the investigations conducted towards the development of a new chemistry for epimerization-free block synthesis of peptides …

Synthesis Of Peptide-Ligand Conjugates And Their Applications, Nitinkumar Dilipkumar Jabre

Wayne State University Dissertations

Three research areas pertaining to this dissertation, (i) synthesis strategies of peptide-ligand conjugates, (ii) their applications and (iii) chemistry of ferryls were surveyed in the introduction chapter. Next, the divergent and dual divergent strategies for the synthesis of non-heme ligand-peptide conjugates were developed. Using these strategies various peptide-ligand conjugates were synthesized via solution as well as solid phase synthesis. The scope and the functional group compatibility of these strategies were also established. The utility of the dual divergent strategy has been demonstrated by synthesizing a small library of metal-binding LHRH analogues. This work showcased the ability of the dual divergent …

Transition Metal-Mediated Higher-Order Cycloaddition Reactions: Application To The Total Synthesis Of Complex Natural Products, Bilal Abou Aleiwi

Wayne State University Dissertations

ABSTRACT

TRANSITION METAL-MEDIATED HIGHER-ORDER CYCLOADDITION REACTIONS: APPLICATION TO THE TOTAL SYNTHESIS OF COMPLEX NATURAL PRODUCTS

by

BILAL ABOU ALEIWI

October 2010

Advisor: Dr. James H. Rigby

Major: Chemistry (Organic)

Degree: Doctor of Philosophy

Chromium (0)-mediated [6ð + 2ð] and [6ð + 2ð + 2ð] cycloaddition reactions between cyclic trienes and alkynes is reported. The development, investigation and the application of these reactions in the total synthesis of complex ring systems and natural products is described. Two natural products, namely, ∆ 9(12) -Capnellene and Echinopines A and B were targeted.

An investigation led to the successful development of a methodology to …

Development And Applications Of Thioacids In Peptide Chemistry And Exploration Of Methods Toward The Stereochemical Elucidation And Synthesis Of Virgineone, Kasinath Sana

Wayne State University Dissertations

ABSTRACT

DEVELOPMENT AND APPLICATIONS OF THIOACIDS IN PEPTIDE CHEMISTRY AND EXPLORATION OF METHODS TOWARD THE STEREOCHEMICAL ELUCIDATION AND SYNTHESIS OF VIRGINEONE

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KASINATH SANA

December 2010

Advisor: David Crich

Major: Chemistry

Degree: Doctor of Philosophy

This dissertation describes investigations toward the development of methods for the synthesis of peptidyl thioacids and thioesters, with particular emphasis on applications in peptide chemistry, and the exploration of methods toward the assignment of the relative and absolute configuration of virgineone and its total synthesis.

The first part of chapter one introduces the general characteristics and reactivity of thioacids, and describes their potential for application …

Dechalcogenative Allylic Selenosulfide And Disulfide Rearrangements For Cysteine Modification And Glycoligation, Venkataraman Subramanian

Wayne State University Dissertations

This thesis describes investigations directed at the development of methods for the selenosulfide and disulfide rearrangements for the permanent functionalization of thiols, and in particular of cysteine and carbohydrate based thiols. Emphasis is placed on the newly invented silver mediated allylic desulfurative rearrangement for the primary modification of thiols and the synthesis of complex oligosaccharide mimics.

Chapter one introduces the concept of chemoselective ligations for the modification of macromolecules like carbohydrates and proteins. It overviews the native and non-native ligation techniques for their modification of such entities with a attention focusing on thiol based ligation techniques. The later part of …

I. Microwave-Influenced Diversity-Oriented Synthesis Of Biologically Relevant Small & Natural-Product-Like Molecules Via Multicomponent Coupling Reactions Ii. Synthetic Studies Toward The Total Synthesis Of The Repeating Tetrasaccharide Unit Of Zwitterionic Polysaccharide Ps A1, Soumava Santra

Wayne State University Dissertations

Microwave-influenced diversity-oriented synthesis of biologically relevant small and natural-product-like molecules via multicomponent coupling reactions (MCCRs) have been investigated. Cheap, readily available starting materials in conjunction of microwave irradiation and employment of environmentally benign solvent (e.g. water) provided a common platform that allowed to access a wide array of structurally and skeletally diverse molecules. The investigation allowed us to establish a new paradigm of diversity-activity relationships (DARs) by tuning reacting components of the MCCRs and proved that in contrary to the conventional use of microwave as a rate accelerating tool, it can be used to influence reactivity of molecules. The method …

Synthesis Of Functionalized Gpi Anchors And Related Glycoconjugates, Benjamin M. Swarts

Wayne State University Dissertations

This dissertation is divided into two chapters describing the background, significance, and synthesis of GPI anchors and GPI-anchored molecules. GPI anchors are a class of complex glycolipids with the primary purpose of attaching cell surface proteins/glycoproteins to the cell membrane. The first chapter is focused on the synthesis of functionalized GPI anchors, and begins with an introductory look at the discovery, structure, biosynthesis, and biological functions of GPIs. Then, after surveying progress and achievements in GPI synthesis, including discussion about current strategic shortcomings in the field that prevent the chemical synthesis of various GPI derivatives, our approach to accessing uniquely …

I-Kinetic And Mechanistic Investigations Of Amino Acid Substrates Reactivities With Ferryl Species, Ahmed Ibrahim Youssef Abouelatta

Wayne State University Dissertations

ABSTRACT

I-KINETIC AND MECHANISTIC INVESTIGATIONS OF AMINO ACID SUBSTRATES REACTIVITIES WITH FERRYL SPECIES

II-SYNTHESIS AND CHARACTERIZATION OF DERIVATIVES OF THE BN-TPEN LIGAND AND THEIR METAL COMPLEXES

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AHMED IBRAHIM YOUSSEF ABOUELATTA

MAY 2011

Advisor: Dr. Jeremy Jacob Kodanko

Major: Chemistry (Organic)

Degree: Doctor of philosophy

The reactivity of tryptophan, methionine, aspartic acid, glutamic acid, histidine and hydrochloride salt of lysine amino acid substrates with the N4Py ferryl species was studied by UV-vis spectroscopy and product characterization. Based on kinetic isotope effect studies and product analysis, an ET-PT mechanism was proposed for the reaction of tryptophan substrate with N4Py ferryl and …