2183-54-2Relevant articles and documents
Lewis Base Catalyzed Intramolecular Reduction of Salicylaldehydes by Pinacol-Derived Chlorohydrosilane
Assoah, Benedicta,Vale, Jo?o R.,Kalenius, Elina,Veiros, Luis F.,Candeias, Nuno R.
supporting information, p. 2910 - 2917 (2018/06/27)
A newly developed stable chlorohydrosilane derived from pinacol is herein described. This was successfully used in the reduction of salicylaldehydes in reasonable to excellent yields (51–97 %). The ability of the hydrosilane to react as a reducing agent is increased upon the in situ formation of a trialkoxyhydrosilane and activation with a Lewis base, as further indicated by density functional theory studies. 1,3-Dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU) was identified to be a suitable catalyst for this metal-free reduction, promoting the regio- and chemoselective reduction of aldehydes in ortho-position to phenols, despite the presence of vicinal ketones. The performance of pinacol-derived chlorohydrosilane in the reduction of salicylaldehydes was further observed to be superior to that of well-established commercially available chlorohydrosilanes.
Modulation of electronic and redox properties in phenolate-rich cobalt(iii) complexes and their implications for catalytic proton reduction
Basu, Debashis,Allard, Marco M.,Xavier, Fernando R.,Heeg, Mary Jane,Schlegel, H. Bernhard,Verani, Claudio N.
, p. 3454 - 3466 (2015/03/05)
We investigate the redox, spectroscopy and catalytic reactivity of new cobalt(iii) complexes based on phenolate-rich [N2O3] ligands. These complexes are described as [CoIII(LX)MeOH], where X indicates the presence of chloro (1), bromo (2), iodo (3), or tert-butyl (4) substituents in the 3rd and 5th positions of each phenolate ring. These substituents modulate the Co(iii) ← PheO- LMCT bands of the parent complexes with 1 (451) > 2 (453) > 3 (456) > 4 (468 nm) and the redox potentials involved with the Co(iii)/Co(ii) and ligand reduction and with the phenolate/phenoxyl oxidation processes. The influence of the substituents on the phenolate pendant arms was also observed on the kinetic parameters; 1 presented a rate constant of 1.0 × 10-3 s-1 whereas 4 showed a considerably slower rate (5.3 × 10-5 s-1). Species 1 and 4 are electrocatalysts towards proton reduction in the presence of weak acid in acetonitrile. A TON of 10.8 was observed for 1 after 3 h of bulk electrolysis at -2.20 VFc/Fc+ using a mercury pool as the working electrode. This journal is
Salalen titanium complexes in the highly isospecific polymerization of 1-hexene and propylene
Press, Konstantin,Cohen, Ad,Goldberg, Israel,Venditto, Vincenzo,Mazzeo, Mina,Kol, Moshe
supporting information; experimental part, p. 3529 - 3532 (2011/05/04)
All lined up: C1-symmetric octahedral titanium complexes (see structure, Ti dark gray, N blue, O red, I purple) whose labile positions reside in different electronic environments were designed using the readily available salalen ligands. With methylalumoxane as co-catalyst, highly active catalysts were obtained, which yielded high-molecular-weight polypropylene with ultra-high isotacticities (see 13C NMR spectrum) and melting transitions. Copyright
