Unlocking Efficient Spontaneous Deracemization: A MOF-Mediated Heterogeneous System Overcomes Catalytic...

Area of Science:

• Materials Science
• Organic Chemistry
• Catalysis

Background:

• Cocrystallization-induced deracemization is crucial for producing enantiopure pharmaceuticals.
• Homogeneous catalysts often face compatibility issues with chiral components, limiting efficiency.

Purpose of the Study:

• To develop a novel heterogeneous catalysis strategy using MOFs to overcome catalyst-component incompatibility in deracemization.
• To demonstrate the use of MOF-encapsulated catalysts for efficient and selective deracemization via cocrystallization.

Main Methods:

• Encapsulation of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) into ZIF-8 to create a ZIF-8@DBU composite catalyst.
• Deracemization of racemic DMY using the ZIF-8@DBU catalyst and varying the coformer (N-benzyl-1-phenylethylamine, NBP) chirality.
• Testing the generality of the strategy with other MOFs like ZIF-67 and ZIF-90.

Main Results:

• The ZIF-8@DBU composite catalyst effectively isolated DBU while retaining racemization activity.
• Efficient and selective deracemization of DMY was achieved, yielding specific enantiomers based on coformer chirality.
• Product yields up to 52% were obtained, exceeding the 50% limit of conventional chiral resolution.
• The MOF composite strategy was successfully extended to ZIF-67@DBU and ZIF-90@DBU.

Conclusions:

• Tailored MOF composites can overcome compatibility barriers in deracemization processes.
• This heterogeneous catalysis approach offers a viable route for producing enantiopure pharmaceuticals.
• The strategy holds promise for broader applications in asymmetric synthesis.