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Omar Omar

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Papers by Omar Omar

Research paper thumbnail of Synthesis of poly(aryleneethynylene)s bearing glucose units as substituentsElectronic supplementary information (ESI) available: experimental procedures and related references, and IR and NMR spectra of all the compounds. See http://www.rsc.org/suppdata/cc/b2/b207753a

Chemical Communications, 2003

A series of poly(aryleneethynylene)s functionalized with acetylated glucopyranosyl units were syn... more A series of poly(aryleneethynylene)s functionalized with acetylated glucopyranosyl units were synthesized by the Pdcatalyzed reaction of trimethylsilylethynyl derivatives with aromatic halides in the presence of silver oxide.

Research paper thumbnail of Synthesis of S Acetyl Oligoarylenedithiols via Suzuki−Miyaura Cross-Coupling

Journal of Organic Chemistry, 2007

Research paper thumbnail of Synthesis and Chiroptical Characterization of an Amino Acid Functionalized Dialkoxypoly(p-phenyleneethynylene

Macromolecules, 2006

2,5-Dialkoxypoly(p-phenyleneethynylene) (3) functionalized with N-t-BOC-L-phenylalanine molecules... more 2,5-Dialkoxypoly(p-phenyleneethynylene) (3) functionalized with N-t-BOC-L-phenylalanine molecules was synthesized by Pd-catalyzed reaction of dioctyloxybis[(trimethylsilyl)ethynyl]benzene (1) with aromatic diiodide 2 linked to two amino acid units by six carbon atoms alkoxy chains. Optical properties were investigated both in solution and in the solid state (as thin films) by absorption, fluorescence and chiroptical spectroscopies (CD and CPL). Polymer 3, that represents one of few fully characterized dialkoxy-substituted PAEs, is also the first example of a poly(aryleneethynylene) (PAE) with amino acidic chiral pendants.

Research paper thumbnail of A sensitivity-enhanced field-effect chiral sensor

Nature Materials, 2008

The ad-hoc-designed organic semiconductor endowed with chiral side groups, the bilayer structure ... more The ad-hoc-designed organic semiconductor endowed with chiral side groups, the bilayer structure and the thin-film transistor transducer provide a significant step forward in the development of a high-performance and versatile sensing platform compatible with flexible organic electronic technologies.

Research paper thumbnail of The synthesis of chiral β-ketosulfoxides by enantioselective oxidation and their stereocontrolled reduction to β-hydroxysulfoxides

Tetrahedron-asymmetry, 2006

Various chiral non-racemic β-ketosulfoxides, a class of compounds frequently used in asymmetric s... more Various chiral non-racemic β-ketosulfoxides, a class of compounds frequently used in asymmetric synthesis, were prepared in good yields by tert-butyl hydroperoxide oxidation of the corresponding sulfides in the presence of a complex between titanium and (S,S)-hydrobenzoin. The ee values of almost all of the purified products were >98%. As ascertained by X-ray analysis and/or by NMR spectroscopy, the use of the (S,S)-form of the ligand led to aryl β-ketosulfoxides with (RS)-configuration and to methyl phenacyl sulfoxide with the (SS)-configuration. Some of the aryl ketosulfoxides were subjected to reduction with DIBAL-H/ZnCl2 and the corresponding β-sulfinylalcohols with an (R,RS)-configuration produced.(R)-2-Naphthyl phenacyl sulfoxideC18H14O2SEe >98% (HPLC)[α]D25=+204.5 (c 1.01, CHCl3)Source of chirality: enantioselective oxidationAbsolute configuration: R(R)-p-Bromophenyl phenacyl sulfoxideC14H11BrO2SEe >98% (HPLC)[α]D25=+174.3 (c 1.00, CHCl3)Source of chirality: enantioselective oxidationAbsolute configuration: R(R)-o-Bromophenyl phenacyl sulfoxideC14H11BrO2SEe >98% (HPLC)[α]D25=+390.4 (c 1.01, CHCl3)Source of chirality: enantioselective oxidationAbsolute configuration: R

Research paper thumbnail of Synthesis of poly(aryleneethynylene)s bearing glucose units as substituentsElectronic supplementary information (ESI) available: experimental procedures and related references, and IR and NMR spectra of all the compounds. See http://www.rsc.org/suppdata/cc/b2/b207753a

Chemical Communications, 2003

A series of poly(aryleneethynylene)s functionalized with acetylated glucopyranosyl units were syn... more A series of poly(aryleneethynylene)s functionalized with acetylated glucopyranosyl units were synthesized by the Pdcatalyzed reaction of trimethylsilylethynyl derivatives with aromatic halides in the presence of silver oxide.

Research paper thumbnail of Synthesis of S Acetyl Oligoarylenedithiols via Suzuki−Miyaura Cross-Coupling

Journal of Organic Chemistry, 2007

Research paper thumbnail of Synthesis and Chiroptical Characterization of an Amino Acid Functionalized Dialkoxypoly(p-phenyleneethynylene

Macromolecules, 2006

2,5-Dialkoxypoly(p-phenyleneethynylene) (3) functionalized with N-t-BOC-L-phenylalanine molecules... more 2,5-Dialkoxypoly(p-phenyleneethynylene) (3) functionalized with N-t-BOC-L-phenylalanine molecules was synthesized by Pd-catalyzed reaction of dioctyloxybis[(trimethylsilyl)ethynyl]benzene (1) with aromatic diiodide 2 linked to two amino acid units by six carbon atoms alkoxy chains. Optical properties were investigated both in solution and in the solid state (as thin films) by absorption, fluorescence and chiroptical spectroscopies (CD and CPL). Polymer 3, that represents one of few fully characterized dialkoxy-substituted PAEs, is also the first example of a poly(aryleneethynylene) (PAE) with amino acidic chiral pendants.

Research paper thumbnail of A sensitivity-enhanced field-effect chiral sensor

Nature Materials, 2008

The ad-hoc-designed organic semiconductor endowed with chiral side groups, the bilayer structure ... more The ad-hoc-designed organic semiconductor endowed with chiral side groups, the bilayer structure and the thin-film transistor transducer provide a significant step forward in the development of a high-performance and versatile sensing platform compatible with flexible organic electronic technologies.

Research paper thumbnail of The synthesis of chiral β-ketosulfoxides by enantioselective oxidation and their stereocontrolled reduction to β-hydroxysulfoxides

Tetrahedron-asymmetry, 2006

Various chiral non-racemic β-ketosulfoxides, a class of compounds frequently used in asymmetric s... more Various chiral non-racemic β-ketosulfoxides, a class of compounds frequently used in asymmetric synthesis, were prepared in good yields by tert-butyl hydroperoxide oxidation of the corresponding sulfides in the presence of a complex between titanium and (S,S)-hydrobenzoin. The ee values of almost all of the purified products were >98%. As ascertained by X-ray analysis and/or by NMR spectroscopy, the use of the (S,S)-form of the ligand led to aryl β-ketosulfoxides with (RS)-configuration and to methyl phenacyl sulfoxide with the (SS)-configuration. Some of the aryl ketosulfoxides were subjected to reduction with DIBAL-H/ZnCl2 and the corresponding β-sulfinylalcohols with an (R,RS)-configuration produced.(R)-2-Naphthyl phenacyl sulfoxideC18H14O2SEe >98% (HPLC)[α]D25=+204.5 (c 1.01, CHCl3)Source of chirality: enantioselective oxidationAbsolute configuration: R(R)-p-Bromophenyl phenacyl sulfoxideC14H11BrO2SEe >98% (HPLC)[α]D25=+174.3 (c 1.00, CHCl3)Source of chirality: enantioselective oxidationAbsolute configuration: R(R)-o-Bromophenyl phenacyl sulfoxideC14H11BrO2SEe >98% (HPLC)[α]D25=+390.4 (c 1.01, CHCl3)Source of chirality: enantioselective oxidationAbsolute configuration: R

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