Selective monodeuteration enabled by bisphosphonium catalyzed ring opening processes.

Area of Science:

• Organic Chemistry
• Photocatalysis
• Isotope Labeling

Background:

• Selective deuterium incorporation is crucial for medical and chemical research.
• Existing hydrogen isotope exchange methods often lead to complete deuteration, limiting applications.
• Developing methods for precise, single-deuterium incorporation remains a significant challenge.

Purpose of the Study:

• To develop a novel photocatalytic protocol for selective monodeuteration of small molecules.
• To utilize the carbon-carbon (C-C) bond as an unconventional functional handle for deuterium incorporation.
• To achieve high selectivity in introducing a single deuterium atom into target molecules.

Main Methods:

• Employing a photocatalytic approach involving radical-mediated C-C bond scission.
• Utilizing a synergistic combination of a bisphosphonium photocatalyst and a thiol catalyst.
• Implementing methanol-d4 (CH3OD) as the deuterium source under photoirradiation.

Main Results:

• Successfully achieved selective monodeuteration, constructing benzylic CDH moieties with high fidelity.
• Demonstrated the operational simplicity of the developed photocatalytic monodeuteration protocol.
• Elucidated the photoinduced electron transfer mechanism of the photocatalyst, revealing a tunable back electron transfer process.

Conclusions:

• The developed protocol offers a precise and efficient method for selective monodeuteration.
• The use of C-C bond activation provides a novel strategy for isotope labeling.
• This advancement holds significant potential for applications in medicinal chemistry and materials science.