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Research paper thumbnail of Azide-functionalized nanoparticles as quantized building block for the design of soft-soft fluorescent polystyrene core-PAMAM shell nanostructures

Journal of Polymer Science Part A: Polymer Chemistry, 2015

ABSTRACT This work deals with the covalent coupling of azide-functionalized polymeric nanoparticl... more ABSTRACT This work deals with the covalent coupling of azide-functionalized polymeric nanoparticles as a reactive core and amino-terminated PAMAM dendrons as a reactive shell. The nanoassemblies thereby obtained could be modified after the dendronization step by grafting an alkynyl Bodipy dye on the unreacted azide moieties. Only a few steps are required to attain nanoassemblies that could mimic dendrimers of high generation with sizes of nano-objects beyond those of dendrimers. The structure of the nanoassemblies are composed of a polystyrene core, an inner shell including the Bodipy dyes along with the internal branches of the PAMAM, and the terminal amino groups from the outer shell. The dendritic shell acts as a protective layer that prevents NP from aggregation in a surfactant free aqueous solution. The nano-objects display absorption and emission maxima above 500 nm with brightness that are the same order of magnitude than Qdots. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015

Research paper thumbnail of A convenient one-step synthesis of mono-N-functionalized tetraazamacrocycles

Journal of the Chemical Society, Perkin Transactions 1, 1999

... been used to prepare tetra-N-substituted macrocycles8 but, to the best of our knowledge, only... more ... been used to prepare tetra-N-substituted macrocycles8 but, to the best of our knowledge, only one example of mono-addition using an ... CH2N); 68.54, 69.17, 69.31, 69.47, 70.44 and 70.49 (CH2O); 105.64, 111.13 and 114.14 (CArH); 133.64, 144.54 and 148.75 (CArO and CArN ...

Research paper thumbnail of Synthesis of Clickable Water-Soluble Poly(amidoamine) Fullerodendrimers and Their Use for Surface Functionalization of Azido-Coated Polymer Nanoparticles

Research paper thumbnail of A convenient synthesis of bis-tetraazamacrocycles

Tetrahedron Letters, 1999

are readily prepared with fairly good yields in a one step procedure from non-protected cyclam. T... more are readily prepared with fairly good yields in a one step procedure from non-protected cyclam. The synthesis involves a selective addition of cyclam on bis-acrylamides in chloroform in the presence of one equivalent of p-toluenesulfonic acid.

Research paper thumbnail of Synthesis of N-tetrasubstituted cyclam derivatives appended with sulfonyl or sulfinyl groups via aza-Michael addition

Tetrahedron, 2007

Vinyl-and alkenylsulfones and sulfoxides are excellent Michael acceptors and have been found to r... more Vinyl-and alkenylsulfones and sulfoxides are excellent Michael acceptors and have been found to react with a number of nucleophiles. [23a] , [23b] , [23c] , [23d] , [23] , [24] , [25] , [26] , [27] , [28] , [29f] , [29g] , [29h] , [29i] , [29] , [29a] , [29b] , [29c] , [29d] , [29e] , [30] , [31] , [32c] , ...

Research paper thumbnail of Azido-Coated Nanoparticles: A Versatile Clickable Platform for the Preparation of Fluorescent Polystyrene Core–PAMAM Shell Nanoparticles

Macromolecules, 2012

The convergent synthesis of fluorescent polystyrene core−PAMAM shell nanoparticles in the 15−20 n... more The convergent synthesis of fluorescent polystyrene core−PAMAM shell nanoparticles in the 15−20 nm diameter range is presented using azido-coated nanoparticles (NP N3 ) as a clickable platform. The coupling of the different partners occurs exclusively on the surface of the cross-linked polystyrene matrix owing to its nonswelling properties in water. PAMAM dendrons having an alkyne moiety at their focal point and peripheral carboxylic acid groups were covalently attached to the surface of azido-coated nanoparticles via a CuAAC reaction. Given the high density of azide anchoring groups on the NP surface (about 560 N 3 per NP) and the size of the PAMAM derivative, the grafting of dendrons was not complete, leaving azide units available for further functionalization with an alkyne dansyl derivative. These new dendron-coated nanoparticles, which possess a number of terminal functional groups comparable to the high eighth generation of PAMAM dendrimers, are obtained in a few steps without tedious chromatographic purification. Dendritic shell saturation levels of 70−85% were reached for these dendron-coated nanoparticles. The colloidal stability of the resulting scaffold was governed by the dendritic shell. Particularly, a pH-dependent electrostatic selfassembly process between the ammonium moieties of the cationic surfactant and carboxylate groups of PAMAM can be switched. This straightforward strategy gives access to dendron-coated nanoparticles as valuable building blocks for the construction of functional nanomaterials.

Research paper thumbnail of A Tunable One-StepN,N′-Disubstitution of 1,4,8,11-Tetraazacyclotetradecane with Acrylamide

European Journal of Organic Chemistry, 2003

ABSTRACT

Research paper thumbnail of An Expedient Synthesis of Perfluorinated Tetraazamacrocycles: New Ligands for Copper-Catalyzed Oxidation under Fluorous Biphasic Conditions

European Journal of Organic Chemistry, 2006

Conjugate additions of cyclam to perfluorohexyl vinyl sulfone and sulfoxide, which act as efficie... more Conjugate additions of cyclam to perfluorohexyl vinyl sulfone and sulfoxide, which act as efficient fluorous Michael acceptors, readily give access to new fluoro-ponytail tetraazamacrocycles in good yields. The solubility of the N-tetrasubstituted macrocycles depends dramatically on the nature of the polar function (SO or SO 2 ): the sulfoxide cyclam derivative is soluble in perfluorodecaline (pfd) and perfluoromethylcyclohexane (pfmc) while the sulfonyl derivative is almost insoluble in organic or fluorous solvents. In agreement with the well known affinity of cyclam for copper(II) ions, stable copper complexes of the fluorous macrocyclic ligands have been isolated and characterized. In chloroform/methanol, complexes with four perfluorinated tails have been obtained from reaction of the tetra-N-perfluorohexylsulfinylsubstituted macrocycle with copper nitrate and copper perfluorocarboxylate. In trifluoroethanol, a selective retro-Michael reaction has been observed and the same reaction [a] 4686 Scheme 2. Preparation of perfluorinated copper(II) complexes

Research paper thumbnail of Orthogonal functionalization of a fullerene building block through copper-catalyzed alkyne–azide and thiol–maleimide click reactions

Tetrahedron, 2014

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.

Research paper thumbnail of Azide-functionalized nanoparticles as quantized building block for the design of soft-soft fluorescent polystyrene core-PAMAM shell nanostructures

Journal of Polymer Science Part A: Polymer Chemistry, 2015

ABSTRACT This work deals with the covalent coupling of azide-functionalized polymeric nanoparticl... more ABSTRACT This work deals with the covalent coupling of azide-functionalized polymeric nanoparticles as a reactive core and amino-terminated PAMAM dendrons as a reactive shell. The nanoassemblies thereby obtained could be modified after the dendronization step by grafting an alkynyl Bodipy dye on the unreacted azide moieties. Only a few steps are required to attain nanoassemblies that could mimic dendrimers of high generation with sizes of nano-objects beyond those of dendrimers. The structure of the nanoassemblies are composed of a polystyrene core, an inner shell including the Bodipy dyes along with the internal branches of the PAMAM, and the terminal amino groups from the outer shell. The dendritic shell acts as a protective layer that prevents NP from aggregation in a surfactant free aqueous solution. The nano-objects display absorption and emission maxima above 500 nm with brightness that are the same order of magnitude than Qdots. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015

Research paper thumbnail of A convenient one-step synthesis of mono-N-functionalized tetraazamacrocycles

Journal of the Chemical Society, Perkin Transactions 1, 1999

... been used to prepare tetra-N-substituted macrocycles8 but, to the best of our knowledge, only... more ... been used to prepare tetra-N-substituted macrocycles8 but, to the best of our knowledge, only one example of mono-addition using an ... CH2N); 68.54, 69.17, 69.31, 69.47, 70.44 and 70.49 (CH2O); 105.64, 111.13 and 114.14 (CArH); 133.64, 144.54 and 148.75 (CArO and CArN ...

Research paper thumbnail of Synthesis of Clickable Water-Soluble Poly(amidoamine) Fullerodendrimers and Their Use for Surface Functionalization of Azido-Coated Polymer Nanoparticles

Research paper thumbnail of A convenient synthesis of bis-tetraazamacrocycles

Tetrahedron Letters, 1999

are readily prepared with fairly good yields in a one step procedure from non-protected cyclam. T... more are readily prepared with fairly good yields in a one step procedure from non-protected cyclam. The synthesis involves a selective addition of cyclam on bis-acrylamides in chloroform in the presence of one equivalent of p-toluenesulfonic acid.

Research paper thumbnail of Synthesis of N-tetrasubstituted cyclam derivatives appended with sulfonyl or sulfinyl groups via aza-Michael addition

Tetrahedron, 2007

Vinyl-and alkenylsulfones and sulfoxides are excellent Michael acceptors and have been found to r... more Vinyl-and alkenylsulfones and sulfoxides are excellent Michael acceptors and have been found to react with a number of nucleophiles. [23a] , [23b] , [23c] , [23d] , [23] , [24] , [25] , [26] , [27] , [28] , [29f] , [29g] , [29h] , [29i] , [29] , [29a] , [29b] , [29c] , [29d] , [29e] , [30] , [31] , [32c] , ...

Research paper thumbnail of Azido-Coated Nanoparticles: A Versatile Clickable Platform for the Preparation of Fluorescent Polystyrene Core–PAMAM Shell Nanoparticles

Macromolecules, 2012

The convergent synthesis of fluorescent polystyrene core−PAMAM shell nanoparticles in the 15−20 n... more The convergent synthesis of fluorescent polystyrene core−PAMAM shell nanoparticles in the 15−20 nm diameter range is presented using azido-coated nanoparticles (NP N3 ) as a clickable platform. The coupling of the different partners occurs exclusively on the surface of the cross-linked polystyrene matrix owing to its nonswelling properties in water. PAMAM dendrons having an alkyne moiety at their focal point and peripheral carboxylic acid groups were covalently attached to the surface of azido-coated nanoparticles via a CuAAC reaction. Given the high density of azide anchoring groups on the NP surface (about 560 N 3 per NP) and the size of the PAMAM derivative, the grafting of dendrons was not complete, leaving azide units available for further functionalization with an alkyne dansyl derivative. These new dendron-coated nanoparticles, which possess a number of terminal functional groups comparable to the high eighth generation of PAMAM dendrimers, are obtained in a few steps without tedious chromatographic purification. Dendritic shell saturation levels of 70−85% were reached for these dendron-coated nanoparticles. The colloidal stability of the resulting scaffold was governed by the dendritic shell. Particularly, a pH-dependent electrostatic selfassembly process between the ammonium moieties of the cationic surfactant and carboxylate groups of PAMAM can be switched. This straightforward strategy gives access to dendron-coated nanoparticles as valuable building blocks for the construction of functional nanomaterials.

Research paper thumbnail of A Tunable One-StepN,N′-Disubstitution of 1,4,8,11-Tetraazacyclotetradecane with Acrylamide

European Journal of Organic Chemistry, 2003

ABSTRACT

Research paper thumbnail of An Expedient Synthesis of Perfluorinated Tetraazamacrocycles: New Ligands for Copper-Catalyzed Oxidation under Fluorous Biphasic Conditions

European Journal of Organic Chemistry, 2006

Conjugate additions of cyclam to perfluorohexyl vinyl sulfone and sulfoxide, which act as efficie... more Conjugate additions of cyclam to perfluorohexyl vinyl sulfone and sulfoxide, which act as efficient fluorous Michael acceptors, readily give access to new fluoro-ponytail tetraazamacrocycles in good yields. The solubility of the N-tetrasubstituted macrocycles depends dramatically on the nature of the polar function (SO or SO 2 ): the sulfoxide cyclam derivative is soluble in perfluorodecaline (pfd) and perfluoromethylcyclohexane (pfmc) while the sulfonyl derivative is almost insoluble in organic or fluorous solvents. In agreement with the well known affinity of cyclam for copper(II) ions, stable copper complexes of the fluorous macrocyclic ligands have been isolated and characterized. In chloroform/methanol, complexes with four perfluorinated tails have been obtained from reaction of the tetra-N-perfluorohexylsulfinylsubstituted macrocycle with copper nitrate and copper perfluorocarboxylate. In trifluoroethanol, a selective retro-Michael reaction has been observed and the same reaction [a] 4686 Scheme 2. Preparation of perfluorinated copper(II) complexes

Research paper thumbnail of Orthogonal functionalization of a fullerene building block through copper-catalyzed alkyne–azide and thiol–maleimide click reactions

Tetrahedron, 2014

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.