A highly enantioselective organocatalytic Wolff rearrangement–amidation–Michael– hemiaminalization stepwise reaction is described involving a cyclic 2-diazo-1,3-diketone, primary amine and α,β-unsaturated aldehyde. Product stereocontrol can be achieved by adjusting the sequence of steps in this one-pot multicomponent reaction. This approach was used to synthesize various optically active spiroc...

The title compound C(23)H(29)NO(5), synthesized by the Amadori rearrangement of α-d-glucose with dibenzyl-amine and the ketalization, is shown to be a β-anomer. The fructopyran-ose ring adopts a chair conformation. The two benzene rings form a dihedral angle of 68.9 (1)°. In the crystal, non-classical inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network.

An investigation into the comparative reactivity of simple β-lactones and β-thiolactones toward a thiol and a primary amine is reported. A simple 3-mercaptomethyl-2-oxetanone is found to undergo rearrangement in the presence of aqueous base to give the corresponding thietane-3-carboxylic acid rather than the 3-hydroxymethyl-2-thietanone. Implications for the use of β-thiolactones in bioorganic ...

Aim of this study was the site-specific conjugation of an epidermal growth factor (EGF)-polyethylene glycol (PEG) chain by click chemistry onto a poly(amido amine) (PAMAM) dendron, as a key step toward defined multifunctional carriers for targeted gene delivery. For this purpose, at first propargyl amine cored PAMAM dendrons with ester ends were synthesized. The chain terminal ester groups were...

A simple and mild catalytic coupling reaction of propargyl halides with organotitanium reagents is reported. The reaction of propargyl bromide with organo-titanium reagents mediated by NiCl2 (2 mol%) and PCy3 (4 mol%) in CH2Cl2 afforded coupling product allenes in good to excellent yields (up to 95%) at room temperature. However, NiCl2(PPh3)2 was the best catalyst for substituted propargyl hali...

The aim of this study was to evaluate the influence of an onium salt in the polymerization kinetics of a dental adhesive model resin. A monomer mixture, based on Bis-GMA, TEGDMA and HEMA, was used as a model dental adhesive resin, which was polymerized using camphorquinone (CQ) as a photo-initiator in addition to either binary or ternary photo-initiator systems. The binary systems were formulat...

Three different tetraazamacrocyclic ligands containing four amide substituents that feature groups (namely allyl, styryl and propargyl groups) suitable for polymerisation have been synthesised. Gadolinium(III) complexes of these three ligands have been prepared as potential monomers for the synthesis of polymeric MRI contrast agents. To assess the potential of these monomers as MRI contrast age...

Predicting the response of individual patients to cytotoxic chemotherapy drugs is critical for developing individualized therapies. With this motivation, an optical molecular imaging approach was developed to detect cisplatin induced changes in the uptake and intracellular retention of choline. Intracellular uptake of choline was characterized using a click chemistry reaction between propargyl ...

In order to find the susceptibility of the Claisen rearrangement and next proton shift reaction of ally) aryl etherto the substiment effects in pan position, the kinetic and the:rmodynamie parameters are calculated at The33 LTP level using 6-3110. b asis set. The calculated activation energies for the rearrangements and protonshift reactions are around 3133 kcaUmol and 52.16 kcal/mol, nap.. liv...

A mild method for the regioselective synthesis of propargyl ethers by the coupling of propargyl alcohols with a range of other alcohols is described. The method employs an air- and moisture-tolerant rhenium-oxo complex ((dppm)ReOCl3) as a catalyst for the formation of sp3-carbon-oxygen bonds without the need for prior activation of the propargyl alcohol or deprotonation of the alcohol nucleophi...