Dealkanative Main Group Couplings across the peri-Gap

Taylor, Laurence J.; Bühl, Michael; Chalmers, Brian A.; Ray, Matthew J.; Wawrzyniak, Piotr; Walton, John C.; Cordes, David B.; Slawin, Alexandra M.Z.; Woollins, J. Derek; Kilian, Petr

Abstract

Here, we highlight the ability of peri-substitution chemistry to promote a series of unique P-P/P-As coupling reactions, which proceed with concomitant C-H bond formation. This dealkanative reactivity represents an interesting and unexpected expansion to the established family of main-group dehydrocoupling reactions. These transformations are exceptionally clean, proceeding essentially quantitatively at relatively low temperatures (70-140 °C), with 100% diastereoselectivity in the products. The reaction appears to be radical in nature, with the addition of small quantities of a radical initiator (azobis(isobutyronitrile)) increasing the rate dramatically, as well as altering the apparent order of reaction. DFT calculations suggest that the reaction involves dissociation of a phosphorus centered radical (stabilized by the peri-backbone) to the P-P coupled product and a free propyl radical, which carries the chain. This unusual reaction demonstrates the powerful effect that geometric constraints, in this case a rigid scaffold, can have on the reactivity of main group species, an area of research that is gaining increasing prominence in recent years.

• Journal Article Type: Article
• Online Publication Date: Dec 14, 2017
• Publication Date: Dec 27, 2017
• Deposit Date: Apr 24, 2023
• Publicly Available Date: May 2, 2023
• Journal: Journal of the American Chemical Society
• Print ISSN: 0002-7863
• Electronic ISSN: 1520-5126
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 139
• Issue: 51
• Pages: 18545-18551
• DOI: https://doi.org/10.1021/jacs.7b08682
• Public URL: https://nottingham-repository.worktribe.com/output/19789437
• Publisher URL: https://pubs.acs.org/doi/10.1021/jacs.7b08682