2-Vinyl-1,1,2-trihalocyclopropanes-valuable five carbon cyclopropane and cyclopropene synthetic intermediates

Syntheses ofgem-Dihalocyclopropanes and Their Use in Organic Synthesis

“…116,117 Haloalkenes substituted by an alkyl or aryl group form appropriate trihalocyclopropanes using PTC or other methods. [118][119][120][121][122][123][124][125] Some examples are presented in Table 2.…”

Three-Membered-Ring-Based Molecular Architectures

“…On the other hand, cyclodimerization of 3,3-dialkylcyclopropenes 274 -R catalyzed by [bis(dibenzylideneacetone)palladium or bis(1,5-cyclooctadiene)palladium] in the absence of phosphine ligands furnished 3,3,6,6-tetraalkyltricyclo[3.1.0.0 2,4 ]hexanes 275 in high yields (Scheme ), 208a-c while nickel catalysts were less efficient 208d. In several rare cases, 1,2-disubstituted cyclopropenes 276 -R underwent spontaneous thermal [2 + 2] dimerization to afford dichlorodiphenyl- ( 277 ), 1,2-divinyl- ( 278 ), or pentacyclic ( 279 ) 211 tricyclo[3.1.0.0 2,4 ]hexanes (Scheme ). At last, dimethyl anti -tricyclo[3.l.0.0 2,4 ]hexane-l,2-dicarboxylate ( 281 ) was prepared by 2-fold γ-dehydrochlorination in dimethyl 3,4-bis(chloromethyl)cyclobutane-1,2-dicarboxylate 280 (Scheme ) …”

π-1,1-Dimethyleneallylmetal and Homologous Complexes: Their Application in Organic Synthesis

“…Likewise, addition of dichloro- and dibromocarbenes, generated from chloro- or bromoform under phase transfer conditions, to 2-chlorobutadiene provided 2-ethenyl-1,1,2-trichlorocyclopropane and 2-chloro-1,1-dibromo-2-ethenylcyclopropane in 28% yields, along with 5% of adducts derived from attack at the non-chlorinated alkene …”