Clicking iron : Cheap and environmentally friendly [Fe(OAc)2] is used for the catalysis of cycloadditions between aryl nitriles and trimethylsilyl azide to prepare substituted 1H‐tetrazoles in good yield (see scheme).
Tuning in : The reaction of halocyclopentane organometallic reagents can be tuned by the choice of metal (see scheme). Cyclopentylmagnesium bromide reduces aldehydes and ketones to the corresponding alcohols. However, in the presence of ZnCl2, normal Grignard addition to the ketones gives tertiary alcohols with complete diastereoselectivity. These protocols were used in the asymmetric synthesis of two medicinally important compounds.
A new way to make a bang : Several functionalized 1‐ethyl‐5‐aminotetrazoles, 1‐ethyl‐5‐nitrimino‐tetrazoles, and copper complexes have been synthesized and their chemical and energetic properties have been comprehensively characterized. The compounds belong to all classes of “energetic materials”: explosives, propellants, and pyrotechnics.
Te for two : Supported by pyridine‐ or carbene‐based ligands, tellurium‐centered dications are prepared in high yield and include a dicationic tellurium analogue of the recently synthesized “carbodicarbene”. The key to accessing these compounds is the isolation of a base‐stabilized form of TeOTf2 (see structure), a new highly electrophilic reagent for tellurium chemistry.
Osmabenzenes can be easily synthesized from two η2‐coordinated olefin osmacycles in the presence of benzonitrile by means of facile hydrogen‐transfer conversions (see graphic). Mechanisms for the formation of osmabenzenes are proposed based on DFT calculations.
Mild‐mannered : The low‐valent aryl gallium(I) species :GaAr′ (Ar′=2,6‐(2,6‐iPr2C6H3)2C6H3) undergoes addition to H2 or NH3 at room temperature and one atmosphere of pressure to afford 1 or 2 (see scheme), which were characterized by X‐ray crystallography and NMR and IR spectroscopy.
Constructing α‐stereogenic amides and ketones : The highly regioselective and enantioselective conjugate addition of 1,3‐dicarbonyl compounds to 1,4‐dicarbonyl but‐2‐enes has been developed with the chiral bicyclic guanidine as catalyst (ee values up to 97 %; see scheme).
Guest Effect : The differences of nitrogen atom positions and the bridge bonds linked to two pyridine rings of some bipyridine guests can significantly affect the binding abilities and inclusion geometries of β‐cyclodextrin with the guests in both the solution and solid states.
