Tuning of Morphology by Chirality in Self-Assembled Structures of Bis(Urea) Amphiphiles in Water.

We present the synthesis and self-assembly of a chiral bis(urea) amphiphile and show that chirality offers a remarkable level of control towards different morphologies. Upon self-assembly in water, the molecular-scale chiral information is translated to the mesoscopic level. Both enantiomers of the amphiphile self-assemble into chiral twisted ribbons with opposite handedness, as supported by Cryo-TEM and circular dichroism (CD) measurements.

Reorganization from Kinetically Stable Aggregation States to Thermodynamically Stable Nanotubes of BINOL-Derived Amphiphiles in Water.

The synthesis and self-assembly behavior of newly designed BINOL-based amphiphiles is presented. With minor structural modifications, the aggregation of these amphiphiles could be successfully tuned to form different types of assemblies in water, ranging from vesicles to cubic structures. Simple sonication induced the rearrangement of different kinetically stable aggregates into thermodynamically stable self-assembled nanotubes, as observed by cryo-TEM.

Salen-Based Amphiphiles: Directing Self-Assembly in Water by Metal Complexation.

Tuning morphologies of self-assembled structures in water is a major challenge. Herein we present a salen-based amphiphile which, using complexation with distinct transition metal ions, allows to control effectively the self-assembly morphology in water, as observed by Cryo-TEM and confirmed by DLS measurements. Applying this strategy with various metal ions gives a broad spectrum of self-assembled structures starting from the same amphiphilic ligand (from cubic structures to vesicles and micelles).

An atom efficient synthesis of tamoxifen.

The direct carbolithiation of diphenylacetylenes and their cross-coupling procedure taking advantage of the intermediate alkenyllithium reagents are presented. By employing our recently discovered highly active palladium nanoparticle based catalyst, we were able to couple an alkenyllithium reagent with a high (Z/E) selectivity (10 : 1) and good yield to give the breast cancer drug tamoxifen in just 2 steps from commercially available starting materials and with excellent atom economy and reaction mass efficiency.

Molecular Motors in Aqueous Environment.

Molecular motors are Nature's solution for (supra)molecular transport and muscle functioning and are involved in most forms of directional motion at the cellular level. Their synthetic counterparts have also found a myriad of applications, ranging from molecular machines and smart materials to catalysis and anion transport. Although light-driven rotary molecular motors are likely to be suitable for use in an artificial cell, as well as in bionanotechnology, thus far they are not readily applied under physiological conditions.

Oxygen Activated, Palladium Nanoparticle Catalyzed, Ultrafast Cross-Coupling of Organolithium Reagents.

The discovery of an ultrafast cross-coupling of alkyl- and aryllithium reagents with a range of aryl bromides is presented. The essential role of molecular oxygen to form the active palladium catalyst was established; palladium nanoparticles that are highly active in cross-coupling reactions with reaction times ranging from 5 s to 5 min are thus generated in situ. High selectivities were observed for a range of heterocycles and functional groups as well as for an expanded scope of organolithium reagents.

HSiCl3-Mediated Reduction of Nitro-Derivatives to Amines: Is Tertiary Amine-Stabilized SiCl2 the Actual Reducing Species?

The mechanism of a recently reported, highly chemoselective metal-free protocol of wide general applicability for the reduction of aromatic and aliphatic nitro-derivatives to amines has been investigated. The reaction is supposed to occur through the generation of a Si(II) reducing species; quantum mechanical calculations, and spectroscopic and experimental data strongly suggest the tertiary amine-stabilized dichlorosilylene to be the most probable reducing agent.

Tuning the LCST and UCST thermoresponsive behavior of poly(N,N-dimethylaminoethyl methacrylate) by electrostatic interactions with trivalent metal hexacyano anions and copolymerization.

Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) has been reported to show both upper critical solution temperature (UCST) and lower critical solution temperature (LCST) behavior in presence of trivalent metal hexacyano anions, which is attractive for the development of smart materials. In this communication, the influence of the double thermoresponsive behavior of PDMAEMA driven by electrostatic interactions is investigated by comparing systems with [Co(CN)6 ](3-) , [Fe(CN)6 ](3-) , and [Cr(CN)6 ](3-) as trivalent anions. Furthermore, tuning of double thermoresponsive behavior of PDMAEMA by incorporating hydrophilic or hydrophobic comonomers is also discussed in the presence of [Fe(CN)6 ](3-) as trivalent ion.