Asymmetric vanadium- and iron-catalyzed oxidations: new mild (R)-modafinil synthesis and formation of epoxides using aqueous H2O2 as a terminal oxidant
作者:Kerstin A. Stingl、Katharina M. Weiß、Svetlana B. Tsogoeva
DOI:10.1016/j.tet.2012.07.052
日期:2012.10
phenyl sulfoxide and the epoxidation of several alkenes, including terminal ones, have been realized by using new iron(III) complexes, generated in situ from primary amine-derived non-symmetrical Schiffbase ligands and aqueous H2O2 as environmentally benign oxidant. Further investigations on vanadium catalysis and the application of both catalytic systems in the synthesis of enantiomerically-enriched
Synthesis of salicylaldehydes bearing bulky substituents in the positions 3 and 5
作者:A. I. Kochnev、I. I. Oleynik、I. V. Oleynik、S. S. Ivanchev、G. A. Tolstikov
DOI:10.1007/s11172-007-0170-5
日期:2007.6
4-disubstituted phenols with paraformaldehyde in the presence of SnCl4 and 2,6-lutidine afforded a number of new salicylaldehydes, containing bulky substituents (tert-butyl, 1-phenylethyl, 1-(4-tert-butylphenyl)ethyl, α-cumyl, and trityl) in the positions 3 and 5.
Design of Schiff base-like postmetallocene catalytic systems for polymerization of olefins: X. Synthesis of phenoxy imino ligands with bulky substituents
作者:I. I. Oleinik、A. I. Kochnev、I. V. Oleinik、S. S. Ivanchev、G. A. Tolstikov
DOI:10.1134/s1070428009010059
日期:2009.1
Reactions of primary amines with salicylaldehydes containing bulky substituents (tert-butyl, 2-phenylpropan-2-yl, triphenylmethyl) in positions 3 and 5 gave a number of new Schiff bases as ligands for complex formation with transition metals.
Asymmetric Epoxidation of Unfunctionalized Alkenes with Ammonium and Phosphonium Monopersulfates Catalyzed by Chiral Mn(III)–Salen Complexes
作者:Pekka Pietikäinen
DOI:10.1016/s0040-4020(99)01008-x
日期:2000.1
Simple cis-disubstituted and trisubstituted alkenes were enantioselectively epoxidized in mild conditions using various Mn(III)-salen complexes as catalysts and quaternary ammonium and phosphonium monopersulfates (Bu4NHSO5, Ph4PHSO5) as oxidants together with amine N-oxides as additives. The effect of the catalyst structure on the stereochemical outcome of the epoxidation reactions was studied. Generally, the 1,2-diphenylethylenediamine-derived complexes were found to give higher asymmetric induction compared to their 1,2-diaminocyclohexane-derived counterparts. Particularly high yields of epoxides (up to 98%) and good enantiomeric excesses (ee up to 93%) were obtained in the epoxidation of 2,2-dialkylchromenes and trisubstituted alkenes. (C) 2000 Elsevier Science Ltd. All rights reserved.