Chiral induction based on carbohydrate ligands in olefin platinum(0) complexes

Area of Science:

• Organometallic Chemistry
• Asymmetric Catalysis
• Carbohydrate Chemistry

Background:

• Chiral ligands are crucial for asymmetric synthesis.
• Prochiral olefins require selective activation for enantioselective transformations.
• Platinum complexes are versatile platforms in catalysis.

Purpose of the Study:

• To investigate the enantioselective recognition of prochiral olefins by a novel glucose-derived chiral N,N-ligand.
• To elucidate the structural and electronic factors governing the observed selectivity in a trigonal platinum environment.
• To understand the stability of the chiral recognition motif in different states.

Main Methods:

• Synthesis of a novel glucose-based chiral N,N-ligand.
• Complexation with a trigonal platinum center.
• Nuclear Magnetic Resonance (NMR) spectroscopy for solution-state analysis.
• X-ray crystallography for solid-state structural determination.

Main Results:

• The chiral ligand demonstrated selective recognition of one enantioface of a prochiral olefin.
• NMR studies confirmed the ligand's ability to induce facial selectivity.
• X-ray crystallography revealed a well-defined chiral pocket of C(2) symmetry around the platinum center.
• This chiral pocket structure was found to be conserved in both solution and solid states.

Conclusions:

• The glucose-derived chiral ligand effectively controls facial selectivity in platinum complexes.
• The C(2)-symmetric chiral pocket is the key structural feature responsible for the observed enantioselection.
• The stability of this chiral pocket in both solution and solid states highlights its robustness for asymmetric induction.