Pyrimidine ligands

In the crystal structure of [Au2(4,6-Me2pym-2-S)2] (4,6-Me2pym-2-S = 4,6-dimethylpyrimidinethiolate) (Figure 2.58a) [311] two independent molecules are present. The intermolecular Au-Au distances are 3.544(1) and 3.783(1) A. The planar molecules interact through n—n interactions which involve the pyrimidine ligands. 

A Suzuki coupling of 5-chloro-2-methyl-6-phenyl-2H-pyridazin-3-one (10) ultimately led to diazino-fused indole 11 and cinnoline 12 and allowed access to a novel pyrimidoisoquinoline ring system in a one-pot fashion <02T10137>. Mn(II)-azido networks of the type [Mn(N3)2(L)] like 13 with new 3-D topologies were obtained using both pyridazine and pyrimidine ligands <02CC64>. 

The phthalazide bis(cinchona) derivatives [(DHQD)2-PHAL] are the best ligands for the asymmetric dihydroxyla-tion of trans, 1,1-disubstituted, and trisubstituted alkenes, enol ethers, a,p-unsaturated ketones, and a,p- and p,y-unsaturated esters, whereas the DHQD-IND ligand turns out to be superior for c/j -alkenes (Table 1). The bis(cinchona) alkaloid-substituted pyrimidine ligand was found to be the best for monosubstituted terminal alkenes. The addition of Methanesulfonamide to enhance the rate of osmate(VI) ester hydrolysis is recommended for all nonterminal alkenes. 

X = OCH2. Y = CH2O. Crys (91 N) 18 i Figure 42 Novel palladium complexes of macrocyclic pyrimidine ligands. 

It has been found that pyrimidine ligands show superior enantioselectivity in AD of terminal alkenes. " Covalent linkage of the quinine alkaloids to a polymer support generates heterogeneous catalysts. ... 

Figure 5.15 [Fe(pyrimidine) H20)(M(CN)2)2] H,0, M=Ag, Au is an example of the cds (CdS04) net. The Ag compound is show with iron-centred nodes and Ag ions are shown as nicks on the links. This structure is triply interpenetrated and the compound exhibits spin crossover with hysteresis and dramatic colour change as well as a solid-state ligand substitution reaction with loss of water, making the pyrimidine ligand bridging irons from two different nets [33].

Given that previous studies had shown that the iridium(iii) complex [IrCl2Cp ]2 (Cp = pentamethylcyclopentadienyl) is an active catalyst for the p-alkylation of secondary alcohols with primary alcohols, a series of iridi-um(iii) complexes 35-36 bearing a Cp unit tethered to an imidazolylidene, as well as complex 37 containing a chelating NHC-pyrimidine ligand, were synthesised (Figure 8.3). ... 

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