Efficient hydroboration of carbonyls by an iron(ii) amide catalyst.

An easily prepared iron(ii) amide precatalyst enables the selective hydroboration of carbonyls with HBpin (pinacolborane) in the absence of any additive. The reactions proceed with low catalytic loading (1-3 mol%) under mild reaction conditions and display wide functional group compatibility. Aldehydes are selectively hydroborated in the presence of other reducible functional groups, such as ketones, alkenes, nitriles, esters, amides, acids and halides.

N-Heterocyclic Carbene-Carbodiimide ("NHC-CDI") Adduct or Zwitterionic-Type Neutral Amidinate-Supported Magnesium(II) and Zinc(II) Complexes.

A series of structurally characterized magnesium and zinc complexes of the form L-M{N(SiMe)} [M = Mg (1) and Zn (2); L = 1,3-diethyl-4,5-dimethylimidazolium-2-{N,N'-bis(4-tert-butylphenyl)amidinate}], L-M{N(SiMe)} [M = Mg (3) and Zn (4); L = 1,3-diethyl-4,5-dimethylimidazolium-2-{N,N'-bis(4-isopropylphenyl)amidinate}], and L-ZnEt (5) bearing a zwitterionic-type neutral amidinate or N-heterocyclic carbene-carbodiimide ("NHC-CDI") adduct and monoanionic amido or alkyl ligands have been reported. The synthesis of compounds 1-5 was achieved by the direct addition of a "NHC-CDI" adduct to a corresponding metal bis(amide) or dialkyl reagent. All compounds 1-5 exist as monomers in the solid state.

Organomagnesium amide catalyzed cross-dehydrocoupling of organosilanes with amines.

The synthesis of novel heteroleptic organomagnesium(ii) amide complexes [IMesMg(Ar){N(SiMe)}]; (IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene), Ar = 2,6-MeCH (Xyl) (1) and 2,4,6-MeCH (Mes) (2) is reported. Both compounds 1 and 2 were confirmed by multinuclear (H, C and Si) magnetic resonance spectroscopy, elemental analysis and single crystal X-ray structural analysis. Furthermore, the organomagnesium amide pre-catalyzed cross-dehydrogenative coupling of organosilanes with amines has been investigated.

Magnesium amide catalyzed selective hydroboration of esters.

Magnesium amide complexes such as Mg{N(SiMe)} (1) LMgN(SiMe)·THF (2) [L = ArNC(NPr)NAr; (Ar = 2,6-Me-CH)] and LMgN(SiMe)·THF (3) [L = ArNC(NPr)NAr; (Ar = 2,6-Pr-CH)] are reported as highly efficient pre-catalysts for the hydroboration of a wide range of esters using pinacolborane (HBpin) under mild reaction conditions. Moreover, we have shown compound 1 catalyzed chemoselective reduction of esters in the presence of other reducible functional groups such as alkene, alkyne and nitro.