“Asymmetric” Catalysis by Lanthanide Complexes

Abstract

velopment of asymmetric Ln catalysts, and their recyclable use, is of increasing importance. This review gives an overview of the most recent developments in catalysis with lanthanide(ii) and lanthanide(iii) complexes. REVIEWS[ + ] The elements specified in Figure 1 include scandium and yttrium, which are not formally defined as lanthanide elements, but as rare earth metals. For the sake of simplicity, in this review these two elements are also abbreviated to Ln.

A Dual-Catalysis Approach to Enantioselective [2 + 2] Photocycloadditions Using Visible Light

“…This observation is consistent with the high kinetic lability of lanthanides (23), which may aid catalyst turnover by facilitating displacement of the bidentate product by a monodentate enone substrate. Next, we evaluated a series of Gd complexes bearing chiral ligands that we hoped would influence the stereochemistry of the [2+2] cycloaddition.…”

Solid-state NMR of quadrupolar halogen nuclei

“…For example, chlorine plays an important biological role in vital chloride ion channels [1][2][3][4] and all three elements are present in a variety of inorganic catalysts [5,6]. Solid-state nuclear magnetic resonance (SSNMR) spectroscopy of the chlorine-35/37, bromine-79/81, and iodine-127 nuclides is often challenging due to their NMR properties; however, the experiment is an excellent probe of the local halogen environment in many solid compounds and materials because of the technique's sensitivity to the local electronic and structural environments.…”

Nanoflow microreactor for dramatic increase not only in reactivity but also in selectivity: Baeyer–Villiger oxidation by aqueous hydrogen peroxide using lowest concentration of a fluorous lanthanide catalyst

“…We report the remarkable increase not only in the reaction rate but also in the regioselectivity of the B-V oxidation with 30% H 2 O 2 even in the low concentration of a fluorous lanthanide complex [10,11] with bis(perfluorooctanesulfonyl)amide ponytail [2] (e.g., Sc[N(SO 2 C 8 F 17 ) 2 ] 3 ) in our nanoflow microreactor system. This fluorous lanthanide catalyst can be fully employed through the microfabricated flow device strictly controlled by nanofeeder Direct Nanoflow System [12][13][14] (DiNaS) (Scheme 1).…”