Straightforward Access to Chiral Phosphangulene Derivatives.

Polycyclic aromatic hydrocarbons including heteroatoms have found a wide range of applications, for instance, in supramolecular chemistry or material science. Phosphangulene derivatives are P-containing polycyclic aromatic hydrocarbons presenting a concave aromatic surface suitable for building supramolecular receptors. However, the applications of this convenient building block have been strongly hampered by a difficult and multistep preparation requiring several protection-deprotection sequences along with the use of harmful reagents.

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.

Platinum-(phosphinito-phosphinous acid) complexes as bi-talented catalysts for oxidative fragmentation of piperidinols: an entry to primary amines.

Platinum-(phosphinito-phosphinous acid) complex catalyzes the oxidative fragmentation of hindered piperidinols according to a hydrogen transfer induced methodology. This catalyst acts successively as both a hydrogen carrier and soft Lewis acid in a one pot - two steps process. This method can be applied to the synthesis of a wide variety of primary amines in a pure form by a simple acid-base extraction without further purification.

Positive Cooperative Effect in Ion-Pair Recognition by a Tris-urea Hemicryptophane Cage.

The synthesis of a hemicryptophane cage combining a CTV unit with a C symmetrical moiety bearing three urea functions is reported. This host was found to bind anions with higher binding constants than other previously reported hemicryptophanes. Due to its heteroditopic character this cage proved to be an efficient ion-pair receptor.

Racemization and transesterification of alkyl hydrogeno-phenylphosphinates.

In this article, we explore, both theoretically and experimentally, the general reactivity of alkyl hydrogeno-phenylphosphinates with alcohols. We show that alcohol molecules act exclusively as nucleophilic species, and add to alkyl hydrogeno-phenylphosphinates, leading to pentacoordinated intermediates. These intermediates are shown to subsequently competitively undergo alcohol eliminations and/or Berry pseudorotations.

Assessment of the electronic properties of P ligands stemming from secondary phosphine oxides.

We report the study of the net donating ability of monodentate and bidentate P ligands stemming from secondary phosphine oxides (SPOs). We experimentally measured and/or calculated the frequencies of CO stretching modes of various metal carbonyl complexes. The inferred electronic properties of the ligands span an unprecedented range, going from π-accepting phosphite-like compounds, to extremely electron-donating ligands outclassing N-heterocyclic carbenes.

Chiral anion-mediated asymmetric ion pairing chemistry.

Chemical reactions and processes often involve cationic reagents, intermediates or products in prochiral or chiral racemic form. To afford instead non-racemic compounds, an asymmetric ion pairing of the cations with chiral anionic counterions can be considered. This review presents recent examples of the synthesis and use of chiral anions for such stereoselective purposes.

A simple route to chiral phosphinous acid-boranes.

We report a simple one-pot synthesis of enantiomerically enriched alkyl- and arylphenylphosphinous acid-borane starting from readily available (R(P))-(-)-menthylhydrogenophenylphosphinate and organolithium reagents.