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《Journal of organometallic chemistry》2007,692(25):5633-5645
Triorganotin(IV) chlorides containing one LCN chelating ligand were hydrolyzed with an excess of sodium hydroxide. The composition of the products is strongly dependent on the nature of the organic groups bound to the tin atom. Di(n-butyl)tin, dimethyltin as well as the diphenyl derivative exhibits an equilibrium between hydroxide and stannoxane forms (oxide), whereas alkyltin species react spontaneously and reversibly with carbon dioxide present in the air to form carbonate species. On the other hand, diphenyl derivatives display virtually no reaction with CO2 towards carbonates, while the di-t-butyl-substituted tin derivative is stable under the same experimental condition and remains as a tin hydroxide. In the case of the dimethyltin derivative, a methyl group migration was observed with displacement of one LCN chelating ligand during the reaction on the air. The coordination geometry of the tin central atom(s) of all studied compounds can be described as trigonal bipyramidal with a dative bonded dimethylamino group occupying one coordination site. The catalytic activity of these compounds in transesterification reactions is generally lower compared to the systems reported in the literature, with the exception of the transesterification of ethyl acetate by cyclohexanol which displays a remarkable activity. 相似文献
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Pottabathula Srinivas Pravin R. Likhar Balsubramanian Sridhar Suresh Bhargava 《Journal of organometallic chemistry》2011,696(3):795-801
The synthesis and structure of palladium(II) complexes bearing uridato/pyridyl ligands as an anionic N-donor coordination sites are reported. The complexes have been shown to be highly active catalysts for the Heck reaction of aryl bromides (TON 4.0×104-9.1×104) and moderate activity for the activation of aryl chlorides under phosphine-free conditions. 相似文献
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Density functional theory(DFT) calculations unambiguously verify that there is little or no direct metal-metal bonding in the dinuclear copper(I) benzamidinate complex [Cu2(LRR')2](2){LRR'=[PhC(NR)(NR')]-(R= 2,6-iPr2C6H3, R'=SiMe3)} with a short Cu-Cu distance[0.24454(4) nm]. 相似文献
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Ronghua Zhang Shan Xu Zhou Luo Prof. Dr. Yuanyuan Liu Prof. Dr. Junliang Zhang 《Angewandte Chemie (International ed. in English)》2023,62(11):e202213600
Central chirality is an important chiral element used in the design of chiral ligands and catalysts. Mostly, the attention of organic chemists is focused on developing of chiral ligands with stable stereogenic centers. However, the N-chirality in chiral ligand design has been rarely explored due to its flexibility. Here we demonstrate the design, synthesis, and application of a class of simple P,N-ligands with flexible N-chirality and their derived iridium complexes with fixed N-chiral stereocenters. Both fixed configurations of the N-stereocenter of the iridium complexes could be selectively formed from the same chiral ligand. This pair of diastereoisomeric iridium complexes showed good performance in the enantiodivergent asymmetric hydrogenation of exocyclic α,β-unsaturated lactams. The N−H group plays an impressive role in catalytic activity. Computational studies emphasized the importance of N-chirality and N−H group. 相似文献
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