- Secondary Deuterium Kinetic Isotope Effects at the Termini of cis-1,2-Divinylcyclopropane and cis-1,2-Divinylcyclobutane in Their 3,3-Sigmatropic Shifts: Evidence for Different Transition-State Structures
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In an effort to understand the substantially lower activation energy for the 3,3-sigmatropic shift of cis-1,2-divinylcyclopropane relative to that of cis-1,2-divinylcyclobutane, we determined the secondary deuterium kinetic isotope effects (KIEs) at the vinyl termini of both materials.For the cyclopropane derivative, kH/kd4 = 1/1.29 (+/- 0.09) at 10 deg C in deuteriochloroform.For the cyclobutane derivative, kH/kd4 = 1/1.04 (+/- 0.02) at 77.7 deg C in hexachlorobutadiene solvent.These KIEs indicate that there is much more bonding at the terminal carbons in the transition state for the rearrangement of the cyclopropane analogue and relatively little bonding at the termini in the rearrangement of the cyclobutane material.
- Gajewski, Joseph J.,Hawkins, Christopher M.,Jimenez, Jose L.
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- The Synthesis and Cycloaddition Reactions of 3-Azabicyclohex-2-ene 3-oxide and 3-Azabicyclohept-2-ene 3-oxide. Highly Strained Bicyclic Nitrones
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The synthesis of two strained bicyclic nitrones is described.Subsequent cycloadditions demonstrated a high degree of regiochemical and stereochemical control.
- Tufariello, Joseph J.,Milowsky, Arnold S.,Al-Nuri, Mohammed,Goldstein, Steven
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p. 267 - 270
(2007/10/02)
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- Cis-N,N,N',N'-tetramethylcyclopropane-1,2-dicarboxamide and use thereof
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cis-N,N,N',N'-Tetramethylcyclopropane-1,2-dicarboxamide as a new chemical compound, and the use thereof in the regulation of plant growth.
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