A comparative study on the catalytic performance of heme and non-heme catalysts: Metal porphyrins versus metal Schiff bases
作者:Atefeh Talaeizadeh、Mahdi Tofighi、Saeed Zakavi
DOI:10.1002/aoc.3967
日期:2018.1
tetra‐n‐butylammonium periodate (TBAP) and tetra‐n‐butyl‐ammonium Oxone (TBAO) have been investigated and compared. Although the metalloporphyrins showed an increased catalytic activity relative to the Schiff base complexes, the former provided no significant catalytic advantage over the latter. Also, a comparable or slightly higher oxidative stability was observed for the Schiff base complexes under the reaction conditions
Integration of heterogeneous catalysts into complex synthetic routes: sequential vs. one-pot reactions in a (Knoevenagel + Mukaiyama–Michael + hydrogenation + transesterification) sequence
作者:José M. Fraile、Nuria García、Clara I. Herrerías、José A. Mayoral
DOI:10.1039/c2cy20442h
日期:——
Heterogeneous catalysts of different nature can be combined in one-pot tandem reactions, but the compatibility issues of catalysts with reagents, products, and by-products make more convenient the application of a sequential procedure, in which the catalyst is filtered after each reaction and the crude is used in the following reaction without purification. In this way the recovery and reuse of each catalyst can be optimized to obtain the maximum productivity. The nature of the reactions, and the catalysts involved in them, conditions the maximum number of successive steps in the sequence. In the case of the (Knoevenagel + MukaiyamaâMichael + hydrogenation + transesterification) process tested in this work, the optimal results are obtained when the sequential method is applied to only three reactions, whereas the four reactions sequence shows limitations in the yield of the last transesterification step.
Syntheses, Crystal Structures, and Magnetic Properties of Mn
<sup>III</sup>
(L)phosphinate Complexes (L =
<i>meso</i>
‐tetraphenylporphyrin or Schiff base)
作者:Sébastien Richeter、Joulia Larionova、Jérôme Long、Arie van der Lee、Dominique Leclercq
DOI:10.1002/ejic.201300246
日期:2013.6.12
structural organization and magneticproperties of MnIII complexes with meso-tetraphenylporphyrin (TPP), bis(3,5-di-tert-butylsalicylidene)ethylenediamine (tBuSalen), and bis(salicylidene)ethylenediamine (Salen) capping ligands assembled with phosphinate ligands such as H2PO2–, PhHPO2– and Ph2PO2– have been investigated. The structural organization and, thus, the magneticproperties in this series depends
Steric and Electronic Effects, Enantiospecificity, and Reactive Orientation in DNA Binding/Cleaving by Substituted Derivatives of [SalenMn<sup>III</sup>]<sup>+</sup>
作者:Dennis J. Gravert、John H. Griffin
DOI:10.1021/ic960196x
日期:1996.1.1
target sites varied with the position of attachment of substituents, but not with the identity of the substituents. The results suggest that substituents alter specificity through both steric and electroniceffects. The 3,3'-difluoro and -dichloro derivatives produced cleavage patterns that match those of the parent complex, suggesting that the activated form of 1 produces cleavage from an orientation
Thermal properties and crystal structures of manganese(III)-salen complexes with the Tf2N anion [Tf2N=bis(trifluoromethanesulfonyl)amide)]
作者:Megumi Okuhata、Tomoyuki Mochida
DOI:10.1016/j.poly.2012.06.004
日期:2012.8
A series of salts comprising cationic manganese(III)-salen complexes and the Tf2N anion has been prepared (salen = N.N'-bis(salicylideneaminato)ethylene, Tf2N = bis(trifluoromethanesulfonyl)amide) to investigate the effects of axial ligands and substituents on their thermal properties. [Mn(salen)L-2][Tf2N] (L= H2O, pyridine) and their 5-butoxysalen analogs undergo thermal desorption of the axial ligands, followed by decomposition above 250 degrees C. The pyridine complexes exhibit two-step ligand desorption, corresponding to the formation of a dimer and later, desorption from the dimer. Complexes with L = 3-butylpyridine and N-butylimidazole melt at 97.6 and 132.7 degrees C, respectively, before ligand desorption. Crystal structures of these and related complexes have been determined. [Mn(salen)(3,3'-bipyridine)][Tf2N] is a coordination polymer with higher thermal stability. (C) 2012 Elsevier Ltd. All rights reserved.