T:Toxic;141-85-5Relevant articles and documents
Selective and Additive-Free Hydrogenation of Nitroarenes Mediated by a DMSO-Tagged Molecular Cobalt Corrole Catalyst
Sch?fberger, Wolfgang,Timelthaler, Daniel,Topf, Christoph
supporting information, p. 2114 - 2120 (2021/07/22)
We report on the first cobalt corrole that effectively mediates the homogeneous hydrogenation of structurally diverse nitroarenes to afford the corresponding amines. The given catalyst is easily assembled prior to use from 4-tert-butylbenzaldehyde and pyrrole followed by metalation of the resulting corrole macrocycle with cobalt(II) acetate. The thus-prepared complex is self-contained in that the hydrogenation protocol is free from the requirement for adding any auxiliary reagent to elicit the catalytic activity of the applied metal complex. Moreover, a containment system is not required for the assembly of the hydrogenation reaction set-up as both the autoclave and the reaction vessels are readily charged under a regular laboratory atmosphere.
Weak halogen bonding in solid haloanilinium halides probed directly via chlorine-35, bromine-81, and iodine-127 NMR spectroscopy
Attrell, Robert J.,Widdifield, Cory M.,Korobkov, Ilia,Bryce, David L.
experimental part, p. 1641 - 1653 (2012/06/30)
A series of monohaloanilinium halides exhibiting weak halogen bonding (XB) has been prepared and characterized by 35Cl, 81Br, and 127I solid-state nuclear magnetic resonance (SSNMR) spectroscopy in magnetic fields of up to 21.1 T. The quadrupolar and chemical shift (CS) tensor parameters for halide ions (Cl-, Br-, I-) which act as electron density donors in the halogen bonds of these compounds are measured to provide insight into the possible relationship between halogen bonding and NMR observables. The NMR data for certain series of related compounds are strongly indicative of when such compounds pack in the same space group, thus providing practical structural information. Careful interpretation of the NMR data in the context of novel and previously available X-ray crystallographic data, and new gauge-including projector-augmented-wave density functional theory (GIPAW DFT) calculations has revealed several notable trends. When a series of related compounds pack in the same space group, it has been possible to interpret trends in the NMR data in terms of the strength of the halogen bond. For example, in isostructural series, the halide quadrupolar coupling constant was found to increase as the halogen bond weakens. In the case of a series of haloanilinium bromides, the 81Br isotropic chemical shift and CS tensor span both decrease as the bromide-halogen XB is weakened. These trends were reproduced using both GIPAW DFT and cluster-model calculations of the bromide ion magnetic shielding tensor. Such trends are particularly exciting given the well-known role that NMR has played historically in the characterization of hydrogen bonding.
Kinetics and mechanism of the aminolysis of dimethyl and methyl phenyl phosphinic chlorides with anilines
Dey, Nilay Kumar,Hoque, Md. Ehtesham Ul,Kim, Chan Kyung,Lee, Bon-Su,Lee, Hai Whang
experimental part, p. 425 - 430 (2010/04/30)
The reactions of dimethyl phosphinic chloride (1) and methyl phenyl phosphinic chloride (2) with X-anilines have been studied kinetically in acetonitrile at 15.0 and 55.0 °C, respectively. The deuterium kinetic isotope effects (KIEs) involving deuterated aniline nucleophiles (XC 6H4ND2) are also reported for the same reactions. The obtained KIEs for 1 are secondary inverse (kH/k D=0.703-0.899H/kD=1.62-2.10> 1). A concerted mechanism involving predominantly backside nucleophilic attack is proposed for the anilinolysis of 1. A concerted mechanism involving predominantly frontside attack via a hydrogen-bonded four-center-type transition state is proposed for the anilinolysis of 2. The degree of steric hindrance is the major factor that determines both the reactivity of the phosphinates and the direction of the nucleophilic attack on the phosphinates. Copyright
