Non-Covalent Immobilization of Rare Earth Heterobimetallic Frameworks and their Reactivity in an Asymmetric Michael Addition

Heterobimetallic Lewis acid catalysts are broadly useful and methods to recycle them have immediate applications. However, their immobilization through covalent binding can be challenging. Non-covalent immobilization of supported asymmetric catalysts is attractive due to ease of preparation and potential for reversible binding. We report a novel non-covalent binding strategy for Shibasaki's REMB framework {RE=rare earth metal; M=Li, Na, K; B=BINOL; RE:M:B=1:3:3, [M-3(sol)(n)][(BINOLate)(3)RE]} and explore the reactivity of the supported catalyst.