25152-47-0Relevant academic research and scientific papers
Effect of phenyl substitution on the lifetime and product distribution of cyclobutylidene: preference change in the rearrangements via 1,2-carbon shift and 1,2-hydrogen shift
Takahashi, Yasutake,Sakakibara, Takurou,Inaba, Makoto,Tomioka, Hideo,Koseki, Shiro,Fujimoto, Kazuyoshi,Umeda, Hiroaki
, p. 3995 - 3999 (2006)
Steady state and laser flash photolytic experiments with precursors 6 and 11 revealed that diphenyl substitution affects the lifetime and reaction mode of cyclobutylidene. 2,2-Diphenylcyclobutylidene 3 (τ 0.1 ns) produces methylenecyclopropane 1 via 1,2-carbon in significant preference to the positional isomer 2 or cyclobutene 4. On the other hand, 3,3-diphenylcyclobutylidene 5 (τ = ca. 4 ns) gives 1,2-hydrogen shift product 4 more favorably than 1,2-carbon shift product 2 together with formal carbene dimer 14. MRMP2//MP2 calculations afford useful results to understand the interrelationship among substitution, structure, and reactivity.
Bu2SnIH-promoted proximal bond cleavage of methylenecyclopropanes and successive radical cyclization and/or Pd-catalyzed coupling reaction
Hayashi, Naoki,Hirokawa, Yusuke,Shibata, Ikuya,Yasuda, Makoto,Baba, Akio
, p. 2912 - 2913 (2008/09/20)
The unprecedented regioselective hydrostannation of methylenecyclopropanes to give vinyltins was achieved using dibutyliodotin hydride (Bu2SnIH), which could be applied to intramolecular radical cyclization. Copyright
Intermediacy of cyclobutylidene in photochemical methylenecyclopropane rearrangement
Takahashi, Yasutake,Mori, Yoko,Nakamura, Akiko,Tomioka, Hideo
, p. 8415 - 8418 (2007/10/03)
Methylenecyclopropane 1 undergoes photochemical rearrangement to 2. Intervention of cyclobutylidene 3 explains not only the rearrangement but also newly obtained products such as cyclobutene 4 and cyclobutylidenecyclobutane 6. Experiments designed to generate cyclobutylidene 3 independently have provided some support for the intermediacy of 3.
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.
Chloropalladation of Phenyl-Substituted Methylenecyclopropanes
Dallas, Bruce K.,Hughes, Russell P.,Schumann, Karen
, p. 5380 - 5383 (2007/10/02)
The chloropalladation reactions of methylenecyclopropanes bearing phenyl substituents on the cyclopropane ring are shown to involve 1,3 addition of the elements of Pd-Cl to the organic molecule, with cleavage of the 2,3 ? bond of the ring.Chloropalladatio
