Computational study on atom-economic alkyne hydrotelluration reaction using benchmarked ECP for Te.

Area of Science:

• Computational Chemistry
• Organometallic Chemistry
• Reaction Mechanism Studies

Background:

• Accurate computational methods are crucial for studying reactions involving tellurium compounds.
• Electronically Corrected Potentials (ECPs) require careful calibration for specific elements and compound types.
• Hydrotelluration offers a pathway to synthesize vinyl tellurides, important organotellurium compounds.

Purpose of the Study:

• To perform geometry and energy calibration for Electronically Corrected Potentials (ECPs) for tellurium-containing compounds.
• To computationally investigate non-catalytic, base-initiated, and radical-initiated hydrotelluration reactions.
• To elucidate the regio- and stereoselective formation mechanisms of vinyl tellurides.

Main Methods:

• Calibration of ECPs, comparing cc-pwCVTZ-PP and def2-TZVP.
• Computational study of gas-phase hydrotelluration mechanisms using the calibrated def2-TZVP.
• Analysis of reaction pathways, transition structures, and stereochemical outcomes.

Main Results:

• The def2-TZVP ECP provided more reliable results for tellurium compounds compared to other tested ECPs.
• The hydrotelluration of unsaturated carbon-carbon triple bonds proceeds via a concerted transition state.
• Regioselectivity was achieved, yielding Markovnikov products under base catalysis and anti-Markovnikov products under radical initiation.

Conclusions:

• The calibrated def2-TZVP ECP is suitable for studying hydrotelluration reactions of tellurium compounds.
• The reaction mechanism is sensitive to the initiation method (base vs. radical), dictating regioselectivity.
• This work provides a foundation for designing selective synthetic routes to vinyl tellurides.