The Coordination Chemistry of Indium

Trialkylstibine Complexes of Boron, Aluminum, Gallium, and Indium Trihalides: Synthesis, Properties, and Bonding

“…The solids appear reasonably air stable but are readily hydrolyzed in solution in organic solvents and, in contrast to the boron and aluminum complexes, can be recrystallized from CH 2 Cl 2 without reaction. Although indium halides form both four- and five-coordinate complexes with phosphines or arsines, ,− the stibines gave only four-coordinate complexes, and addition of more Sb i Pr 3 to solutions of [InX 3 (Sb i Pr 3 )] in CH 2 Cl 2 did not change the 115 In NMR spectra, showing that there was no tendency to produce a higher coordination number in solution. The X-ray crystal structures of [GaX 3 (Sb i Pr 3 )] (X = Cl, I), [GaBr 3 (SbEt 3 )], [InCl 3 (SbR 3 )], and [InI 3 (SbR 3 )] (R = Et, i Pr) each contain distorted-tetrahedral centers at antimony and the group 13 atom site (Figures and ) with the [GaBr 3 (SbEt 3 )] and [InX 3 (SbEt 3 )] having eclipsed conformations, while the other three are staggered.…”

“…The mismatch in electronic properties of chloride and the stibine would be expected to lead to a significant efg, and this promotes sufficiently fast relaxation to result in loss of the resonance. The ν­(M–X) vibrations in the far-IR spectra are typical of complexes of both metals of type [MX 3 (L)]. ,, …”

Acyclic Remote 1,5- and 1,4,5-Stereocontrol in the Catalytic Stereoselective Reactions of β-Lactams with Aldehydes: The Effect of the N-Methylimidazole Ligand

“…However, the effect of N -methylimidazole on the stereochemical course of the process resulting in a significantly higher ( Z )-selectivity remains unclear, which is detailed in further paragraphs. In most reports on coordination chemistry of indium­(I), reactions of indium­(I) halides with bases (ligands) cause its redox disproportionation. , However, besides the number of reports on quite stable achiral In­(I) complexes with no synthetic application, there are remarkable examples of InI complexes able to catalyze allylations and crotylations of hydrazones, with organoindiums derived from allyl boronates . Although we observed an increased rate of disproportionation of InI in the presence of N -methylimidazole, especially in the THF/HMPA mixtures, the generated in situ complex proved to be stable enough to enable an overall crotylation process to proceed when THF or a THF/EtOH mixture was employed.…”

“…As reported, the application of our previously developed conditions (2 equiv of benzaldehyde, 2 equiv of InI, and 5 mol % Pd­(PPh 3 ) 4 in a 3:1 THF/HMPA mixture at 25 °C) to the β-lactam 1 resulted in less than 10% of its conversion within 1 h, whereas no further progress was observed during the next 23 h (Table , entry 1) . We realized that this is most likely due to the instability of InI in polar aprotic solvents including HMPA, in which it readily disproportionates, preventing full conversion of the less active, as compared to β-lactams bearing an unsubstituted vinyl moiety, ( E )-propenyl-β-lactam 1 . Indeed, the removal of HMPA from the reaction conditions in the next attempt led to a significantly higher 53% conversion, but the result was still not satisfactory in terms of yield and product distribution (51% yield, Z / E = 43:57, Table , entry 2).…”

Structural and spectroscopic studies of bis(2-amino-6-methylpyrimidinium-4-(1H)-one) aquapentachloridoindate(III) monohydrate

“…Carty and Tuck [7] discussed the range of coordination numbers observed for In(III) compounds in relation to the cation size and conditions of preparation. We report here synthesis, crystal structure, and solid-state NMR and infrared data for characterization of a new organic halogenoindium(III) material, bis(2-amino-6-methylpyrimidinium-4-(1H)-one) aquapentachloridoindate(III) monohydrate, (C 5 It is worthy to note that pyrimidines and related compounds are of extreme importance as three of the four common DNA nucleobases, i.e cytosine, thymine, and uracil are pyrimidine derivatives.…”