- DER EINFLUSS VON WECHSELWIRKUNGEN DURCH DEN RAUM UND UEBER BINDUNGEN AUF DIE WALSH-ORBITALE VON SPIROCYCLOPROPYLVERBINDUNGEN
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The PE spectra of spiro- and dispirocyclopropyl derivatives of cyclobutane are investigated, and an assignment of the PE bands based on MINDO/3- and 4-31G calculations is proposed.The influence of the ?CH2 orbitals of the cyclobutane ring is discussed by means of a LCBO model: in the case of the 1,3-derivative through-bond interactions cause an inversion of the natural order of the orbitals, whereas through-space interactions reduce the conjugative splitting of the Walsh orbitals in the 1,2-derivative.The proposed model naturally explains also the various splittings of the Walsh orbitals in rotanes.
- Hemmersbach, P.,Klessinger, M.
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- The non-reaction of methylene with the carbon-carbon bond
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Methylene has been shown not to react with the carbon-carbon bonds of spiropentane and spiro[3.3]heptane.
- Wu, Guo-Xian,Maitland Jr., Jones,Doering, William von E.,Knox, Lawrence H.
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p. 9913 - 9920
(2007/10/03)
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- REACTIONS OF DIAZOALKANES WITH UNSATURATED COMPOUNDS. 6. CATALYTIC CYCLOPROPANATION OF UNSATURATED HYDROCARBONS AND THEIR DERIVATIVES WITH DIAZOMETHANE
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A systematic study has been conducted of the catalytic reaction of diazomethane with cyclic and polycyclic unsaturated hydrocarbons, conjugated dienes, as well as with a series of functionalized unsaturated conpounds.The feasibility of using transition metal, nontransition metal, and rare earth metal compounds of, for example, Co, Ni, Zr, Rh, and Dy, has been demonstrated for the first time.It has also been established that Pd(acac)2 has very high activity as a catalyst for the cyclopropanation of terminal and endocyclic double bonds by diazomethane, and that its activity is reduced upon the introduction of n-donor ligands or in the presence of strong polar solvents.
- Dzhemilev, U. M.,Dokichev, V. A.,Sultanov, S. Z.,Khusnutdinov, R. I.,Tomilov, Yu. V.,et al.
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p. 1707 - 1714
(2007/10/02)
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