Visible light-mediated NHC and photoredox co-catalyzed 1,2-sulfonylacylation of allenesviaacyl and allyl radical cross-coupling

Abstract

Allyl radicals served as a crucial intermediate in the radical functionalization of fundamental raw materials and received increasing attention. Despite the significance, allyl-radicals-participated radical cross-couplings were rare and mainly focused...

Radical Acylation of Alkenes by NHC‐Organocatalysis

“…Mechanistic studies indicated that the key step of the transformation was also the cross‐coupling between ketyl‐radical 40‐III and allenyl radical 40‐IV . Additionally, a robust radical 1,2‐sulfonylacylation of allenes was also achieved by the same group under nearly the same catalytic conditions (Scheme 40d) [58] . Therefore, a lot of valuable sulfonyl‐containing multi‐substituted allyl ketones 40‐10 could be produced under extremely mild conditions with excellent regioselectivity.…”

“…Additionally, a robust radical 1,2sulfonylacylation of allenes was also achieved by the same group under nearly the same catalytic conditions (Scheme 40d). [58] Therefore, a lot of valuable sulfonyl-containing multi-substituted allyl ketones 40-10 could be produced under extremely mild conditions with excellent regioselectivity.…”

Recent advances in three-component radical acylative difunctionalization of unsaturated carbon–carbon bonds

“…In 2023, the Zheng and Zhang group developed NHCs/PC dual-catalyzed radical 1,2-sulfonyl acylation of allenes 51-1 with sulfinates 51-3 and aroyl fluoride 51-2 (Scheme 51). 141 Extremely mild conditions allowed for a broad substrate scope and functional group tolerance. Similar to previous reports, in situ generated sulfonyl radicals 51-7 underwent regioselective addition to allenes generating allyl radicals 51-8 , which are trapped by persistent BIR affording sulfonyl-substituted olefins.…”

Recent advances in combining photo- and N-heterocyclic carbene catalysis

“…By replacing the 1,3-enyene acceptor of the sulfonyl radical with an allene, these investigators also achieved 1,2-sulfonylacylation of allenes to provide valuable sulfonyl-containing multisubstituted allyl ketones (Scheme 45). 50 3.2.3 Formation of phenyl radicals. Recently, the Studer group reported a C-H Acylation of arenes and heteroarenes through cooperative photoredox/NHC radical catalysis (Scheme 46).…”