35802-38-1Relevant academic research and scientific papers
Polylithiumorganic compounds. Part 29: C,C Bond cleavage of phenyl substituted and strained carbocycles using lithium metal
Maercker, Adalbert,Oeffner, Kristian S.,Girreser, Ulrich
, p. 8245 - 8256 (2007/10/03)
The reaction of phenyl substituted cyclopropanes phenylcyclopropane and 1,1-diphenylcyclopropane, phenyl substituted bicyclobutanes 1- phenylbicyclobutane, 1-methyl-3-phenylbicyclobutane, 1-methyl-2,2- diphenylbicyclobutane, as well as phenyl substituted spiropentanes phenylspiropentane and 1,1-diphenylspiropentane with lithium metal or lithium di-t-butylbiphenyl (LiDBB) was investigated. Under suitable reaction conditions and choice of solvent in all cases cleavage of the single bond next to the activating phenyl group was observed. The dilithiumorganic compounds thus obtained are sufficiently stable and can be trapped with electrophiles. Lithium hydride elimination is observed as follow-up reaction only in a few cases. The corresponding anions of the strained ring systems 1-lithio-2,2- diphenylcyclopropane, 1-lithio-3-phenylbicyclobutane, 1-lithio-3-methyl-2,2- diphenylbicyclobutane, and 1-lithio-4-phenylspiropentane, which can be obtained by lithium bromine exchange or by metalation of the unsubstituted carbocycle, do not show any cleavage upon reaction with lithium metal. The reaction of phenyl substituted cyclopropanes, bicyclobutanes as well as spiropentanes with lithium metal with formation of highly reactive dilithiumorganic compounds was investigated. In all cases cleavage of the bond next to the phenyl substituent(s) was observed.
