Heavy Atom Quantum Mechanical Tunneling in Total Synthesis.

Area of Science:

• Physical chemistry
• Organic chemistry
• Quantum mechanics

Background:

• Radical coupling reactions are vital in natural product total synthesis.
• Understanding reaction kinetics is essential for efficient synthesis design.

Purpose of the Study:

• To quantify the contribution of quantum mechanical tunneling to radical coupling reaction rates.
• To assess the significance of tunneling in carbon sp2-centered reactions.

Main Methods:

• Density functional theory (DFT) computations were employed.
• Calculations focused on radical coupling reactions involving carbon sp2 centers.

Main Results:

• Quantum mechanical tunneling contributed between approximately 15% and 52% to reaction rates at room temperature.
• Tunneling was identified as a significant factor influencing the speed of these reactions.

Conclusions:

• Quantum mechanical tunneling plays a critical role in the kinetics of radical coupling reactions.
• Consideration of tunneling is recommended for the strategic design of complex synthetic schemes in natural product synthesis.