Property and Reactivity of Fluoro(silyl)acetylenes and Fluoro(stannyl)acetylenes

Abstract

Fluoro(silyl)acetylenes and fluoro(stannyl)acetylenes underwent a radical addition reaction of THF to furnish the corresponding fluorinated cyclic ethers in moderate to good yields. These intriguing addition reaction proved to proceed via a radical reaction mechanism.

Monofluorination of Organic Compounds: 10 Years of Innovation

“…Most fluoroacetylenes, bearing either a hydrogen, silane, alkyl or phenyl group, are known to be unstable in their pure form (but to some extent stable in solution) at room temperature. Indeed, they can trimerize quickly to form fluorinated Dewar benzenes, which decompose to fluorinated benzenes upon heating. , They can also engage in cycloaddition reactions. , When simply solubilized in THF at −78 °C, they react in a radical pathway, forming fluoroalkenes . Finally, they can react as electrophiles with organolithium compounds to generate internal alkynes. , The only report prior to 2005 of an isolable fluoroalkyne was a conjugated fluoroenyne …”

“…557e,559 When simply solubilized in THF at −78 °C, they react in a radical pathway, forming fluoroalkenes. 560 Finally, they can react as electrophiles with organolithium compounds to generate internal alkynes. 557d,e The only report prior to 2005 of an isolable fluoroalkyne was a conjugated fluoroenyne.…”

Synthesis of Monofluoroalkenes: A Leap Forward

“…The synthesis of monofluoroalkenes is also possible starting from fluoroacetylenes. 112 The Hanamoto group developed the radical addition of tetrahydrofuran to 1-fluoro-2-silyl-and 1-fluoro-2-stannylacetylenes in moderate to good yields with slight selectivity towards the E-alkenes (Table 11). After in situ formation of the fluoroacetylene, a trace amount of oxygen generates the THF radical and initiates the reaction.…”

Chemoselective Reduction of Functionalized 5-Nitroisoxazoles: Synthesis of 5-Amino- and 5-[Hydroxy(tetrahydrofuran-2-yl)amino]isoxazoles

“…Tetrahydrofuran radical addition to different classes of organic compounds in the presence of radical initiators is well-documented. The addition of the tetrahydrofuran-2-yl radical to double C=C 10 and triple C≡C 11 bonds, and to C=O and C=N 12 groups is known. There are a few reports that describe the addition of tetrahydrofuran to activated C-X bonds in alkenes, 13 alkynes, 14 aryl compounds, 15 fullerene, 16 oxime ethers, 17 and also the addition to S-S (in disulfides), 18 activated O-H (alcohols), 19 and N-H (amines) bonds.…”