Chemoselective oxygen-centered radical cyclizations onto silyl enol ethers.
A new oxygen-centered radical cyclization onto silyl enol ethers has been developed and utilized for the synthesis of versatile siloxy-substituted tetrahydrofurans. The reactions display excellent chemoselectivity for cyclization onto the electron-rich silyl enol ether when competing terminal alkene cyclization, 1,5-hydrogen abstraction, and beta-fragmentation pathways are present. The increased chemoselectivity also allows for the synthesis of tetrahydropyrans, a challenging substrate class to access using oxygen-centered radical alkene cyclizations due to competing 1,5-hydrogen abstractions.
Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Maria
M
Zlotorzynska
Huimin
H
Zhai
Glenn M
GM
Sammis
D000475:Alkenes / Q000737:chemistry; D003500:Cyclization; D004987:Ethers / Q000138:chemical synthesis* / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D015394:Molecular Structure; D010100:Oxygen / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D014001:Tin / Q000737:chemistry
D000475:Alkenes; D004987:Ethers; D005609:Free Radicals; D005663:Furans; D012821:Silanes; C018674:tetrahydrofuran; D014001:Tin; D010100:Oxygen