Diastereoselective Synthesis and Catalytic Activity of Two Chiral cis‐Dioxidomolybdenum(VI) Complexes

Abstract

Two enantiomerically pure chiral dioxidomolybdenum(VI) complexes (1 and 2) of the type [MoO 2 L] (L = dianionic, tetradentate ONNO-ligand) were synthesized and investigated in enantioselective oxidation reactions. The solid-state structures of complex 1 and 2, determined via single-crystal X-ray diffraction analysis revealed two fundamentally different coordination geometries: a C1-symmetric cis-isomer (Λ-1), and a C2symmetric cis-α isomer (Δ-2). In both cases, only one of the two possible helical enantiomers (Λ-or Δ-helix) was formed. The complexes were examined as precatalysts in the epoxidation of the challenging prochiral substrate trans-stilbene, using [a]

Selective synthesis of 2‐substituted 2,3‐dihydroquinazolin‐4(1H)‐ones and quinazolin‐4(3H)‐ones catalyzed by Schiff base dioxomolybdenum(VI) complex

“…Schiff bases compounds have been widely used, for example as adsorbents to remove heave metal ions from liquid, 30,31 or as catalysts; for instance, Schiff base molybdenum(VI) complexes have been successfully used to catalyze olefins epoxidation, 32–34 sulfides 35 and alcohols oxidation 36 . Concerning molybdenum compounds for the synthesis of quinazolinones, Mo(CO) 6 was reported to promote the reaction as “CO” source but not as catalyst, also molybdenum doped ZnO was used as catalyst for the synthesis of quinazolinones 37 .…”

Ligand coordination sphere effect of Schiff base cis‐dioxomolybdenum(VI) complexes in selective catalytic oxidation of alcohols

“…Recently, several Schiff base molybdenum(VI) complexes have been developed and used as catalysts for various oxygen atom transfer reactions, such as olefins epoxidation, 29–31 sulfides oxidation, 32 and alcohols oxidation 33 . Regarding alcohol oxidations, various Schiff base molybdenum complexes, such as magnetic complex, 34 Mo−V bimetallic complex, 35 and μ ‐O{MoO 2 } 2 core complex, 36 have been evaluated in alcohol oxidation with TBHP or H 2 O 2 as oxidants yielding the corresponding aldehydes or ketones.…”

Manganese Ferrite Nanoparticles Modified by Mo(VI) Complex: Highly Efficient Catalyst for Sulfides and Olefins Oxidation Under Solvent‐less Condition

“…Transition metal complexes are widely used as catalysts for production of important organic compounds Mo(VI) complexes have in particular found interest for the oxidation of olefins‐ and sulfides‐ into epoxides‐ and sulfoxides‐ to provid access to industrially important compounds, surfactants, intermediates, drug, antifungal agents and epoxy resins . Homogeneous catalysts are mainly used for these chemical transformations.…”