73347-22-5Relevant academic research and scientific papers
Oxygen transfer from organoelement oxides to carbon monoxide catalyzed by transition metal carbonyls
Kelly, Anne M.,Rosini, Glen P.,Goldman, Alan S.
, p. 6115 - 6125 (2007/10/03)
Solutions of Rh(PR3)2(CO)Cl (R = Me, Ph) are found to catalyze the rapid transfer of oxygen from amine oxides or organoselenium oxides to carbon monoxide; however, the rhodium complexes undergo no reaction with the oxides in the absence of added CO. Kinetic studies indicate that the catalytically active species is the CO-substituted complex Rh(PR3)(CO)2Cl, although it is not present in any observable concentration under the conditions of the reaction. Ir(PPh3)2(CO)2Cl also acts as an efficient catalyst precursor for the same oxygen transfer reactions, although like the rhodium complex it undergoes little or no direct reaction with the oxides. The catalytically active species is again found to be the product of substitution of a ligand (in this case, chloride) by CO: [Ir(PPh3)2(CO)3]+ in either ion-paired or unpaired states. Among substrates with weak E-O bonds (E = N, Se), reactivity correlates with substrate basicity in accord with a transition state having the character of a nucleophilic attack (at carbonyl carbon). Oxides with much stronger E-O bonds, even the highly basic triphenylarsine oxide, are much less reactive; the transition state in this case apparently involves significant E-O bond breaking and is presumably not well modeled as a simple nucleophilic attack. Pt(Ph3As)(CO)Cl2 was found to act as a good catalyst precursor for deoxygenation of arsine oxide, but this system is apparently very complex and the nature of the catalytically active species has not been elucidated.
Preparation of the Complexes trans- and their Isomerisation to cis Isomers
Anderson, Gordon K.,Cross, Ronald J.
, p. 1988 - 1991 (2007/10/02)
Treatment of halide-bridged dimers 2> (X is halide; L is tertiary phosphine or arsine) by carbon monoxide gives solutions of the trans isomers of , some of which can be isolated.These compounds readily lose CO and isomerise to cis deriv
Carbonyl Insertion at : The Effects of varying the Anionic Ligand X and the Neutral Ligand L
Anderson, Gordon K.,Cross, Ronald J.
, p. 712 - 715 (2007/10/02)
From the reaction of HgPh2 with cis-, the benzoyl complexes can be isolated when L = PEt3, PMe2Ph, PMePh2, PPh3, or P(C6H11)3, but when L = P(C6H4Me-o)3, AsMePh2, or AsPh3 only the complexes are formed.Metathetical replacements of the chloride ions in lead to the corresponding bromide or iodid complexes.Low temperature n.m.r. studies show that the reaction between HgPh2 and cis- gives first the carbonyl derivative , from which CO insertion proceeds.The equilibrium positions in solution between L> (each with Ph trans to L) and the binuclear benzoyl complexes are reported.The effect of X on the equilibrium position depends on the bridging ability of that group in the benzoyl dimers, stronger bridges favouring the insertion product.The neutral ligans L exert an effect by both electronic and steric factors.The magnitude of the trans influence of L directly affects the tendency of the trans phenyl group to migrate to CO, unless a critical size of L is exceeded.In these cases, the steric bulk of L favours the mononuclear carbonyl derivative.
