Dioxidomolybdenum(VI) and -tungsten(VI) complexes with tripodal amino bisphenolate ligands as epoxidation and oxo-transfer catalysts

: Hossain MK, Schachner JA, Haukka M, Lehtonen A, Mösch-Zanetti NC, Nordlander E

Publisher: PERGAMON-ELSEVIER SCIENCE LTD

: 2017

: Polyhedron

: POLYHEDRON

: 134

: 275

: 281

: 7

: 0277-5387

: 1873-3719

DOI: https://doi.org/10.1016/j.poly.2017.04.036

The molybdenum(VI) and tungsten(VI) complexes [MO2(L)] (M = Mo (1), W (2), H2L = bis(2-hydroxy-3,5-di-tert-butybenzyl)morpholinylethylamine) were synthesized and the complexes were used to catalyze oxotransfer reactions, viz. sulfoxidation, epoxidation and benzoin oxidation. For comparison, the same reactions were catalyzed using the known complexes [MO2(L')] (M = Mo (3), W (4), H2L' = bis(2-hydroxy-3,5-di-tert-butybenzyl)ethanolamine) and [MO2(L")] (M = Mo (5), W (6), H2L" bis(2-hydroxy-3,5-di-tert-butybenzyl)diethyleneglycolamine). The oxo atom transfer activity between DMSO and benzoin at 120 degrees C was identical for all studied catalysts. Reasonable catalytic activity was observed for sulfoxidation by the molybdenum complexes, but all tungsten complexes were found to be inactive. Similarly, the molybdenum complex 1 exhibited relatively good epoxidation activity, while the corresponding tungsten complex 2 catalyzed only the epoxidation of cis-cyclooctene with low activity. (C) 2017 Published by Elsevier Ltd.