Versatile Ligands for Palladium-Catalyzed Asymmetric Allylic Alkylation

Palladium complexes of the chiral diphosphanes 1 and 2 which possess a rigid backbone and a large bite angle catalyze the alkylation of allyl compounds with both high enantioselectivities and reaction rates, particularly with less sterically demanding substrates. 1 : R=Me, X=S; 2 : R=H, X=C(CH₃)₂.     

Cation-Induced Macroscopic Ordering of Non-Mesomorphic Modules—A New Application for Metallohelicates

The subtle balance between organized and chaotic domains in the nondiscoidal ligand in the helicate 1 , which displays liquid crystalline properties, represents the key element which enables the local molecular architecture to be integrated into an organized macroscopic ensemble.     

Modification of polycyanurate networks with protic additives based on polydimethylsiloxane

Hydroxy telechelic polycaprolactone / polydimethylsiloxane / polycaprolactone triblock copolymers were used to modify aromatic polycyanurate networks through a polycondensation-induced phase separation. Model studies revealed that the cyclotrimerization mechanism in the presence of alcohol functions was complex. The additives, which activate the reaction, are finally chemically linked to the matrix. Both thermodynamic and kinetic features result in very finely divided morphologies, with highly interpenetrated phases which contribute to a great improve of the static mechanical properties.     

Verbesserungen des Spectroskopes

Ohne Zusammenfassung     

Aminomethylation of lithiated nicotinamide: access to new pyridolactams

New 2,3-dihydropyrrolopyridinones were conveniently prepared by trapping lithiated pyridine carboxamides with highly reactive formimines. In this Letter, we report that a wide range of N-functionalised compounds can be synthesised in one step by this process, allowing the presence of ethers, acetals or ester moieties.     

Postfunctionalization of poly(propargyl methacrylate) using copper catalyzed 1,3‐dipolar Huisgen cycloaddition: An easy route to electro‐optic materials

A one‐pot synthetic route based on copper‐catalyzed Huisgen reaction has been developed to functionalize a methacrylate propargylic polymer with azido‐substituted moieties. This procedure was used for the preparation of electro‐optic materials containing well‐known Disperse Red One (DR1) chromophores along with bulky adamantyl moieties (Adam). The postfunctionalization of the propargylic polymer was successfully achieved using different molar ratios of DR1/Adam. These novel polymers exhibit high glass transition temperature owing to the rigid structure of adamantyl units. Moreover, the second harmonic generation measurements demonstrated the effectiveness of adamantyl groups to act as insulating shield limiting thus the electrostatic interactions between chromophores. Indeed, higher optimal chromophore concentration (50 mol %) than in conventional DR1‐containing polymers (30 mol %) allowed us to increase the d₃₃ coefficient up to 92 pm/V. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5652–5660, 2009     

Enantioselective alkylidenecyclopropanation of norbornenes with terminal alkynes catalyzed by palladium–phosphinous acid complexes

Pd(II)-coordinated phosphinous acids catalyzed the formal enantioselective [2+1] cycloaddition of norbornene derivatives with terminal alkynes. The absolute configuration of (+)-3aa was assigned using VCD.