Hydrogen–deuterium exchange between LiBH4and LiBD4. Isotope effects on the1H and11B nuclear magnetic resonance spectra of species LiBHnD4 –n

1974 ◽  
pp. 294-295 ◽  
Author(s):  
Bruce D. James ◽  
Brian E. Smith ◽  
Roger H. Newman
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Isotope Effects ◽  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Nuclear Magnetic Resonance Spectra ◽  
Hydrogen Deuterium ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

Thermolysis of some 2,3-diazabicyclo[3.3.0]octene systems

1970 ◽  
Vol 48 (4) ◽  
pp. 628-632 ◽  
Author(s):  
Manfred P. Schneider ◽  
Robert J. Crawford
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Kinetic Isotope ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The kinetics and products of thermolysis of 2,3-diazabicyclo[3.3.0]oct-2-ene (1), 2,3-diazabicyclo-[3.3.0]octa-2,7-diene (2), and exo-4-methyl-2,3-diazabicyclo[3.3.0]octa-2,7-diene (3) are described and compared with previously studied pyrazolines. The secondary kinetic isotope effects of 1-d2 and 2-d2 have been measured. The synthesis and nuclear magnetic resonance spectra of these compounds and their thermolysis products are discussed.

Nuclear magnetic resonance studies. XXXII. Rearrangement, isomerization, and deuterium exchange via β-enolization in bicyclooctenones. A 2H nuclear magnetic resonance study

1978 ◽  
Vol 56 (10) ◽  
pp. 1342-1347 ◽  
Author(s):  
A. K. Cheng ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nuclear Magnetic Resonance Study ◽  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Group Comparison ◽  
Magnetic Resonance Study ◽  
Hydrogen Deuterium ◽  
Derivatives Of ◽  
Nuclear Magnetic

The equilibration of the α,α -diniethyl derivatives of bicyclo[2.2.2]octenone, bicyclo[3.2.1]-oct-2-en-6-one, and its Δ3 isomer has been examined at 155 and 185 °C in tert-BuO−/tert-BuOH. Using 2Hmr spectroscopy the rates and stereoselectivity of hydrogen–deuterium exchange in each of these ketones have been determined for equilibrations with tert-BuOD as solvent. The relative reactivities for exchange at the allylic and vinylic sites compared to the analogous results for the corresponding olefins reveal a significant activating effect of the carbonyl group. Comparison of the data with those for the corresponding saturated ketones shows that the double bond enhances the rate of isomerization appreciably and increases the bias of the equilibrium toward the [3.2.1] skeleton.

scholarly journals Nuclear magnetic resonance studies. XXX.Hydrogen–deuterium exchange in bicyclo[3.2.1] and -[2.2.2]octenes through allylic and vinylic anions

1977 ◽  
Vol 55 (1) ◽  
pp. 50-55 ◽  
Author(s):  
A. K. Cheng ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Magnetic Resonance Studies ◽  
H Nmr ◽  
Hydrogen Deuterium ◽  
Nuclear Magnetic

Bicyclo[3.2.1]oct-2-ene undergoes hydrogen–deuterium exchange through allyl and vinyl carbanionic intermediates under strongly basic conditions, tert-BuO−/tert-BuOD) at 185 °C. Only allylic exchange had been observed in previous studies with tert-BuO−/DMSO. Since the 2-tert-butoxybicyclo[3.2.1]octanes are stable under these conditions an addition–elimination sequence cannot account for exchange at C-3. The relative rates of exchange at C-2, -3, and -4, and the stereoselectivity at the allylic site were determined by 2H nmr. For comparison, the rate of olefinic exchange in bicyclo[2.2.2]octene was also measured.

Sign in / Sign up

Export Citation Format

Share Document