Topology-Encoded Asymmetric Tandem Catalysis in BINAP-Based Metal-Organic Frameworks

Area of Science:

• Materials Science
• Catalysis
• Organic Chemistry

Background:

• Asymmetric tandem catalysis in heterogeneous systems is challenging due to the need for integrated chiral confinement, defined active sites, and multi-step compatibility.
• Robust solid-state materials are required to host these complex catalytic processes.

Purpose of the Study:

• To demonstrate that framework topology can encode ligand conformation and catalytic function within chiral metal-organic frameworks (MOFs).
• To develop heterogeneous catalysts for efficient asymmetric tandem reactions using topology-encoded control.

Main Methods:

• Assembly of an enantiopure tetratopic BINAP-derived linker into chiral MOFs with distinct network topologies.
• Postsynthetic incorporation of Palladium (Pd) and Rhodium (Rh) centers into the MOFs.
• Evaluation of catalytic performance in asymmetric tandem coupling/[2 + 2] cycloaddition and 1,4-addition/hydrogenation reactions.

Main Results:

• Distinct MOF topologies induced topology-dependent conformational changes in the BINAP backbone, creating well-defined chiral confinement.
• Heterogeneous catalysts with atomically resolved active sites enabled direct correlation between topology, ligand conformation, and reactivity.
• High efficiency, enantioselectivities up to 99% ee, and diastereomeric ratios up to 11.5:1 were achieved.
• Catalysts exhibited excellent stability and recyclability.

Conclusions:

• Framework topology serves as an effective strategy for encoding ligand conformation and catalytic function in heterogeneous catalysts.
• Topology-encoded control facilitates predictable and efficient asymmetric tandem catalysis in MOFs.
• This approach advances the design of advanced heterogeneous catalysts for complex organic transformations.