A new approach to .alpha.,.alpha.-difluoro-functionalized esters
作者:Zhen Yu Yang、Donald J. Burton
DOI:10.1021/jo00017a026
日期:1991.8
The addition reaction of iododifluoroacetates to alkenes is initiated by copper powder (10-20 mol %) at 50-60-degrees-C. Both terminal and internal alkenes give good yields of adducts. The reaction is also applicable to alkenes containing a variety of functional groups, such as epoxy, hydroxy, ketone, ester, and phosphonate moieties. This reaction can be carried out either neat or in solvents such as hexane, benzene, acetonitrile, DMF, DMSO, and HMPA and is suppressed by p-dinitrobenzene and di-tert-butyl nitroxide. A single electron transfer initiated radical mechanism is proposed. In the presence of nickel dichloride hexahydrate, reduction of the adducts with zinc in moist THF provides the corresponding alpha,alpha-difluoro esters in good yields.
Copper catalyzed addition reaction of iododifluoroacetates to olefins
作者:Zhen-Yu Yang、Donald J. Burton
DOI:10.1016/s0022-1139(00)82877-8
日期:1989.12
The addition of iododifluoroacetates to alkenes is catalyzed by copper powder (10-20 mol %) at 50° to 60°C. The reaction can be carried out neat or in hexane or benzene as solvent. Both terminal and internal alkenes gave good yields (65-83%). Reduction of the adduct with tributyltin hydride provides the α, α-difluoroacetate.