Physical Separation of Enantiomeric Products by Compartmentalized Parallel Kinetic Resolution.

Accessing each enantiomer of a chiral molecule starting from a racemic mixture remains a daunting challenge in chemistry. Indeed, until now, only a few solutions exist to separate enantiomers of an equimolar mixture of a chiral precursor. In this study, we establish a new strategy to prepare simultaneously and physically separate both enantioenriched enantiomers of a molecule starting from a racemic substrate.

Ditopic Covalent Cage for Ion-Pair Binding: Influence of Anion Complexation on the Cation Exchange Rate.

A new hemicryptophane host with a ditopic molecular cavity combining a cyclotriveratrylene (CTV) unit with a tris-urea moiety was synthesized. The complexation of halides, tetramethylammonium (TMA) cation, and ion pairs was investigated. A positive cooperativity was observed, since halides display a higher binding constant when a TMA cation is already present inside the cage.

Highly Selective Fluoride Recognition by a Small Tris-Urea Covalent Cage.

A highly selective recognition of fluoride was achieved through the design of a small hemicryptophane cage () presenting a southern tris-urea hosting moiety. The resulting host-guest complex has been characterized by electrospray ionization-high-resolution mass spectrometry, H and F NMR, and X-ray diffraction techniques. In particular, X-ray diffraction analysis of [·F] reveals that the encapsulation of one fluoride, within , occurs through NH···F H-bonding with the six NH residues of the tris-urea ligand.

Preparation of Vinylcyclopropanes by Sodium Mediated Reductive Isomerization of Methylenecyclopropanes.

We disclosed therein a new reaction of reductive isomerization of methylenecyclopropanes (MCPs) to vinylcyclopropanes (VCPs). On treatment with sodium metal in liquid ammonia, MCPs bearing a C-O bond at allylic position undergo both a reductive cleavage of the C-O bond and an isomerization of the C-C double bond giving rise to VCPs. The scope of the reductive isomerization was investigated and showed a broad applicability since various functional groups are tolerated.

Biomimetic self-assembling acylphthalocyanines.

We synthesized a series of biomimetic self-assembling phthalocyanines equipped with carbonyl groups as recognition motifs, a central zinc atom and diverse solubilizing alkyl chains mimicking for the first time with these robust pigments the natural chlorosomal bacteriochlorophylls. Upon self-assembly a very broad and red-shifted Q-band absorption extending to over 900 nm is put into evidence.