A new approach to .alpha.,.alpha.-difluoro-functionalized esters
摘要:
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.
A convenient AIBN-initiated radical addition of ethyl iododifluoroacetate to alkenes
作者:Leo Leung、Bruno Linclau
DOI:10.1016/j.jfluchem.2008.03.002
日期:2008.10
The AIBN-initiated addition of ethyl 4-iodo-2,2-difluoroacetate to a variety of alkene substrates is described. The addition generally led to the corresponding addition products in good to excellent yields and various functional groups could be tolerated under the reaction conditions.
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.