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Dealkanative Main Group Couplings across the peri-Gap
Laurence J Taylor1, Michael Bühl1, Brian A Chalmers1
1University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland.
Journal of the American Chemical Society
|December 2, 2017
Summary
Peri-substitution chemistry enables novel P-P/P-As coupling reactions with C-H bond formation. This dealkanative reactivity expands main-group dehydrocoupling, offering clean, efficient, and diastereoselective transformations.
Area of Science:
- Main-group chemistry
- Organophosphorus chemistry
- Radical chemistry
Background:
- Peri-substitution chemistry offers unique reactivity.
- Main-group dehydrocoupling reactions are established but limited.
- Geometric constraints can influence main-group element reactivity.
Purpose of the Study:
- To explore peri-substitution chemistry for novel coupling reactions.
- To investigate dealkanative P-P/P-As coupling with C-H bond formation.
- To expand the scope of main-group dehydrocoupling.
Main Methods:
- Utilizing peri-substituted precursors for coupling reactions.
- Employing radical initiators (e.g., azobis(isobutyronitrile)) to study reaction kinetics.
- Performing Density Functional Theory (DFT) calculations to elucidate the reaction mechanism.
Main Results:
- Achieved unique P-P and P-As coupling reactions with concomitant C-H bond formation.
- Demonstrated clean, quantitative, and highly diastereoselective transformations at 70-140 °C.
- Identified a radical-based mechanism involving phosphorus-centered radicals and propyl radicals.
Conclusions:
- Peri-substitution chemistry provides a powerful platform for novel main-group coupling.
- Dealkanative reactivity represents a significant expansion of dehydrocoupling reactions.
- Geometric constraints imposed by rigid scaffolds are crucial for controlling main-group element reactivity.
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