A Phosphanyl Phosphagermene and its Reactivity.

Reaction of a nucleophilic germylene Ge[CH(SiMe)] with the phosphanyl phosphaketene [{(HC)(NDipp)}P]PCO induces decarbonylation to form a phosphanyl phosphagermene [{(HC)(NDipp)}P]P=Ge[CH(SiMe)] (1; Dipp=2,6-diisopropyl-phenyl). Addition of CO or MeCN to 1 results in [3+2]-cycloaddition reactions to afford five-membered heterocycles. This mode of reactivity is reminiscent of that observed for frustrated Lewis pairs, with the pendant phosphanyl group acting as a base and the germanium center as a Lewis acid.

Formation, Reactivity and Decomposition of Aryl Phospha-Enolates.

Two lithium phospha-enolates [RP=C(Si Pr )OLi] were prepared by reaction of triisopropyl silyl phosphaethynolate, Pr SiPCO, with aryl lithium reagents LiR (R=Mes: 1,3,5-trimethyl phenyl; or Mes*: 1,3,5,-tri-tertbutyl phenyl). Monomer/dimer aggregation of the enolates can be modulated by addition of 12-crown-4. Substitution of lithium for a heavier alkali metal was achieved through initial formation of a silyl enol ether, followed by reaction with KO Bu to form the corresponding potassium phospha-enolate [MesP=C(Si Pr )OK] .

A Cyaphide Transfer Reagent.

The cyanide ion plays a key role in a number of industrially relevant chemical processes, such as the extraction of gold and silver from low grade ores. Metal cyanide compounds were arguably some of the earliest coordination complexes studied and can be traced back to the serendipitous discovery of Prussian blue by Diesbach in 1706. By contrast, heavier cyanide analogues, such as the cyaphide ion, C≡P, are virtually unexplored despite the enormous potential of such ions as ligands in coordination compounds and extended solids.

A Structured Approach To Cope with Impurities during Industrial Crystallization Development.

The perfect separation with optimal productivity, yield, and purity is very difficult to achieve. Despite its high selectivity, in crystallization unwanted impurities routinely contaminate a crystallization product. Awareness of the mechanism by which the impurity incorporates is key to understanding how to achieve crystals of higher purity.

Aluminium-mediated carbon-carbon coupling of an isonitrile.

Cp*Al reacts with diphenylacetylene to form a Cp*-substituted 1,4-dialuminacyclohexene. The dialuminacyclohexene reacts with four equivalents of an isonitrile to couple the terminal carbon atoms, forming 6 new carbon-carbon bonds and resulting in a zwitterionic diamide ligand which contains a carbocationic backbone.

Ligand coordination modulates reductive elimination from aluminium(iii).

Oxidative addition of inert bonds at low-valent main-group centres is becoming a major class of reactivity for these species. The reverse reaction, reductive elimination, is possible in some cases but far rarer. Here, we present a mechanistic study of reductive elimination from Al(iii) centres and unravel ligand effects in this process.