We report here a C–H homoallylation reaction of aromaticketones with methylenecyclopropanes (MCPs) only using a catalytic amount of Fe(PMe3)4. A variety of aromaticketones and MCPs are applicable to the reaction to form ortho-homoallylated aromaticketones selectively via regioselective scission of the three-membered rings. The homoallylated products are amenable to further elaborations, providing
Unusual methylation reaction of gem-bromofluorospiropentanes with methyllithium
作者:Elena B. Averina、Kseniya N. Sedenkova、Ilya S. Borisov、Yuri K. Grishin、Tamara S. Kuznetsova、Nikolai S. Zefirov
DOI:10.1016/j.tet.2009.05.032
日期:2009.7
A series of novel gem-bromofluorospiropentanes were synthesized and investigated in the reaction with methyllithium. Either substitution of the fluorine atom for a methyl group or rearrangement into methylated cyclobutene derivatives occurred under these conditions.
Nickel-catalyzed reactions of methylenecyclopropanes and thioanhydrides afford sulfur-containing heterocyclic compounds via [1+4] cycloaddition. The reactions represent a new use for methylenecyclopropane as a possible one-carbon building block to replace carbon monoxide, isocyanides, and Fischer carbene complexes.
A nickel-catalyzed [4 + 1] cycloaddition of enones with methylenecyclopropanes leading to dihydrofurans was developed. The reaction outcome is attributed to the transformation of methlenecyclopropane, which is incorporated Into a five-membered ring as a one-carbon fragment.