Omer Rasheed - Academia.edu (original) (raw)

Papers by Omer Rasheed

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Declaration Copyright statement Acknowledgements List of abbreviations CHAPTER I: INTRODUCTION 1.... more Declaration Copyright statement Acknowledgements List of abbreviations CHAPTER I: INTRODUCTION 1.1 Azo Dyes 1.1.1 Oxidation of primary aromatic amines 1.1.2 Reduction reactions of nitro-aromatic compounds 1.1.3 Electrophilic reactions of diazonium salts 1.1.4 Diazo-coupling via diazonium salts 3.31 Synthesis of 3-(4-nitrophenyl)-2(1H)-pyridinone (341)

ChemMedChem, 2021

Mincle agonists have been shown to induce inflammatory cytokine production, such as tumor necrosi... more Mincle agonists have been shown to induce inflammatory cytokine production, such as tumor necrosis factor‐alpha (TNF) and promote the development of a Th1/Th17 immune response that might be crucial to development of effective vaccination against pathogens such as Mycobacterium tuberculosis. As an expansion of our previous work, a library of 6,6′‐amide and sulfonamide α,α‐d‐trehalose compounds with various substituents on the aromatic ring was synthesized efficiently in good to excellent yields. These compounds were evaluated for their ability to activate the human C‐type lectin receptor Mincle by the induction of cytokines from human peripheral blood mononuclear cells. A preliminary structure–activity relationship (SAR) of these novel trehalose diamides and sulfonamides revealed that aryl amide‐linked trehalose compounds demonstrated improved activity and relatively high potency cytokine production compared to the Mincle ligand trehalose dibehenate adjuvant (TDB) and the natural ligand trehalose dimycolate (TDM) inducing dose‐dependent and human‐Mincle‐specific stimulation in a HEK reporter cell line.

Bioorganic & Medicinal Chemistry, 2020

ChemistrySelect, 2018

The transition metal catalyzed direct site‐selective carbon –hydrogen functionalization is ubiqui... more The transition metal catalyzed direct site‐selective carbon –hydrogen functionalization is ubiquitous in organic synthesis and has reached an impressive level of sophistication and efficiency emerging as a powerful synthetic strategy for C–C bond and C–X bond formation to access various useful arylated organic molecules. For the past two decades, directing group strategy has been used for selective activation and functionalization of certain inert C–H bonds. Despite the enormous development in this field, still, the majority of systems require two redundant steps, i. e. installation and removal of DGs. To overcome these limitations, recently, traceless and multitasking groups were invented as a partial solution to DG release however installation still remains unsolved. Ideally, use of the catalytic directing group, which can be reversibly linked to the substrate and can serve as an efficient directing role would circumvent this problem and is considered as one of the most efficient and powerful strategies for the non‐activated C–H functionalization (C(sp2)–H or C(sp3)–H). In this review, we describe the enormous advances in this field for direct selective C–H functionalization without involving additional steps, i. e. installation and removal of directing groups and also discuss less explored but significant non‐covalent interactions such as hydrogen bonding or ion pairing, which helps to control the selectivity of a substrate in a catalytic organic reaction.

Synlett, 2018

A ruthenium-catalyzed functionalization of benzaldehyde substrate with organic azides promoted by... more A ruthenium-catalyzed functionalization of benzaldehyde substrate with organic azides promoted by various transient directing groups has been developed. In this approach, C–H amination is achieved via a transient aldimine intermediate in good to excellent yields.

European Journal of Organic Chemistry, 2017

Synlett, 2015

ABSTRACT The BHQ benzannulation reaction of azo-substituted (2-ally-laryl)trichloracetates, leadi... more ABSTRACT The BHQ benzannulation reaction of azo-substituted (2-ally-laryl)trichloracetates, leading to azo-naphthalenes, is described. The scope and limitations of this new synthesis of azoaromatics is discussed .

Org. Biomol. Chem., 2015

Treatment of (ortho-trimethysilyl)aryl phenylsulfonates with fluoride anion initiates a Truce-Smi... more Treatment of (ortho-trimethysilyl)aryl phenylsulfonates with fluoride anion initiates a Truce-Smiles rearrangement leading to the formation of bi-aryls.

Dalton Trans., 2017

The synthesis and complexation of azo dye-S3N crown conjugates with Ag(i), Cu(ii) and Hg(ii) is d... more The synthesis and complexation of azo dye-S3N crown conjugates with Ag(i), Cu(ii) and Hg(ii) is described.

Synthesis

The elaboration of azo dyes using a variety of transition-metal-catalysed reactions (Stille, Heck... more The elaboration of azo dyes using a variety of transition-metal-catalysed reactions (Stille, Heck, Ullmann, and Suzuki couplings) is reported. This methodology has been applied to the synthesis of functionalised coumarin azo dye conjugates, substrates which may find potential application in the development of new sensors.