Privileged phosphine-based metal-organic frameworks for broad-scope asymmetric catalysis

Area of Science:

• Materials Science
• Catalysis
• Organic Chemistry

Background:

• Metal-organic frameworks (MOFs) offer tunable porous structures for catalysis.
• Achieving high enantioselectivity in MOF-based catalysts remains a challenge.
• Post-synthetic modification allows for the introduction of active metal sites into pre-formed MOFs.

Purpose of the Study:

• To synthesize a robust Zr-based MOF using a BINAP-derived linker (BINAP-MOF).
• To post-synthetically metalate BINAP-MOF with Ru and Rh complexes.
• To evaluate the catalytic performance of these functionalized MOFs in asymmetric organic transformations.

Main Methods:

• Synthesis of a Zr-based metal-organic framework (MOF) with a BINAP-derived dicarboxylate linker.
• Post-synthetic metalation of the MOF with Ruthenium (Ru) and Rhodium (Rh) complexes.
• X-ray Absorption Fine Structure (XAFS) studies to characterize the metal coordination environment.
• Testing catalytic activity and enantioselectivity in asymmetric addition and hydrogenation reactions.

Main Results:

• The synthesized BINAP-MOF is robust and porous.
• Rh-functionalized BINAP-MOF demonstrated high enantioselectivity (up to >99% ee) and 3x higher activity than homogeneous catalysts.
• Ru-functionalized BINAP-MOF contained Ru-BINAP precatalysts with coordination environments identical to homogeneous analogs.
• The catalysts efficiently mediated asymmetric additions and hydrogenations.

Conclusions:

• Post-synthetically metalated BINAP-MOFs serve as versatile single-site solid catalysts.
• These MOF-based catalysts exhibit excellent enantioselectivity and activity for various asymmetric organic reactions.
• The developed MOF catalysts offer a promising alternative to homogeneous catalysts in important organic synthesis.