MODIFICATION OF SINGLET CARBENE REACTIVITIES BY SOLVENT

Article abstract of DOI:10.1016/S0040-4020(01)96743-2

The solvent effect on the reactivity of singlet carbenes has been investigated.Competition reactions between pairs of alcohols for arylcarbenes in various solvents indicates that the O-H insertion selectivity is influenced only by 1,4-dioxane.Thus, phenylcarbene is some 33 times more reactive toward methanol relative to t-butyl alcohol in 90 molpercent dioxane than without solvent.Similar competition reactions between alcohol and olefin indicate that the O-H insertion-addition selectivities of arylcarbenes are considerably altered by dioxane.These results are interpreted as indicating that dioxane stabilizes singlet carbenes by complexing with its ione pairs of electrons.