Alkali metal complexes amides

The low affinity of the alkali metals for neutral P-donor ligands has hampered efforts to synthesize complexes in which there is a genuine R3P-M interaction (see Section I). However, this poor affinity may be overcome by incorporating a remote phosphine functionality into a potentially chelating anionic ligand, such as a phosphine-substituted alkoxide, amide, or aryl, and several alkali metal complexes of such ligands have been isolated. 

Lanthanide amides Ln[N(SiMe3)2]3()tt-Cl)Li(THF)3 or Ln[N(SiMe3)2]3 have been reported to be efficient catalysts for amidation of aldehydes with amines under mild conditions without the use of peroxide and base. But this kind of catalyst is not suitable for the amidation of aldehydes with secondary cycUc amines. Heterobimetallic lanthanide/alkali metal complexes stabilized by phenolate ligand are new classes of bimetallic catalysts for amidation of... 

As homogeneous catalysts, alkali metals. Li —amide,and transition metal complexes such as Ni[P(OC2Hs)3]4, Ni acetylacetonate, PdBr2(Ph2PCH2PPh2),... 

Reaction of the same neutral borabenzene-ligand adduct, C5H5B-PMe3, with a transition, rather than an alkali, metal alkyl or amide can furnish r 6-boratabenzene complexes in a single step (Scheme 8).17 This efficient transformation presumably proceeds through initial ir-coordination of CsHsB-PMes to the transition metal, followedby an intramolecular substitution reaction. In contrast to other approaches to the synthesis of T 6-boratabenzene complexes, this synthetic route does not have a parallel in if-cyclopentadienyl chemistry. 

This section is limited to complexes which have a group 1 metal in conjunction with another, different main group metal, but also includes Cu and Cd since they exhibit properties akin to their main group analogs. It is also limited mainly to those complexes in which the metals find themselves attached to different atoms and there is a particular emphasis on compounds with alkali metal-carbon bonds of various types, except where the evolution of inverse crown complexes is discussed. There are many more heterobimetallic-heteroatom complexes (e.g., mixed metal amides), but these lie outside the scope of this current review though references may be found to them in the references for the complexes described herein. 

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