The mode of co-ordination of the multidentate ligand 2,2Ј-dimethyl-4,4Ј-bipyrimidine (L) was found to depend on the metal ion, the crystallization conditions, the metal-to-ligand ratio, and the anion. With nickel a chelating co-ordination through the endo-dentate nitrogen donor set is observed in the molecular complex [NiCl 2 (L)(H 2 O)]ؒCH 3 NO 2 , derived from hot CH 3 NO 2 . With Cu(NO 3 ) 2 and CuI-CH 3 CN one-and two-dimensional (1-D and 2-D) co-ordination polymers of formula ∞

Aminoboranes have been shown to be highly efficient and mild iminium ion generators in the Mannich-type aminative coupling of aldehydes with silyl ketene acetals. By using aminoboranes bearing bulky amino groups, such as a diisopropylamino group, free secondary amines can be successfully used as the amino component in a three-component Mannich reaction with aldehydes and silyl ketene acetals.

No abstract

Cobalt(ii), zinc(ii) and cadmium(ii) salts react with the new spacer ligand 2,2A-bi-1,6-naphthyridine 1 to give 2D-planar (4,4) frameworks which interpenetrate such that each grid window of each sheet has two other sheets passing through it with all sheets being equivalent whereas copper(i) tetrafluoroborate and 1 form a 2 1 -helicoidal chain with neigboring chains interlocking through an aromatic p-p interaction.

Unlike ordinary boron enolates, such as dialkylboryl (R(2)B) and dialkoxyboryl ((RO)(2)B) derivatives, reactions of diaminoboryl ((R(2)N)(2)B) enolates with aldehydes proceed with the concurrent transfer of amino and enoxy groups from the boron to the aldehyde carbon, yielding beta-amino ketones in a selective manner.