21661-44-9Relevant academic research and scientific papers
Effect of the Orientation of an α-Substituent on Vicinal 13C-1H Spin-Spin Coupling Constants
Beuzekom, Aart A. van,Leeuw, Frank A. A. M. de,Altona, Cornelis
, p. 68 - 74 (1990)
The magnitude of the NMR spin-spin coupling constant, 3J(CH), between a vicinal 13C-1H pair depends, inter alia, on the value of the torsion angle Φ(13C-C-C-H) and is influenced by the presence of an electronegative substituent located on the c
Sodium diisopropylamide-mediated dehydrohalogenations: Influence of primary- A nd secondary-shell solvation
Ma, Yun,Algera, Russell F.,Woltornist, Ryan A.,Collum, David B.
supporting information, p. 10860 - 10869 (2019/09/30)
Eliminations of alkyl halides by sodium diisopropylamide (NaDA) in tetrahydrofuran (THF)/hexane or THF/N,N-dimethylethylamine (DMEA) solutions are facile and complementary to analogous reactions of lithium diisopropylamide in THF. Rate studies show a dominance of monomer-based metalations and prevalent secondary-shell solvation effects overlaid on primary-shell effects. 1-Halooctanes exclusively undergo elimination rather than substitution. Rate and isotopic labeling studies on 1-bromooctane reveal an E2-like elimination pathway via trisolvated NaDA monomer. By contrast, 1-chlorooctane is eliminated via disolvated monomer through a carbenoid mechanism. exo-2-Norbornyl chloride and bromide are also eliminated via disolvated monomer; a syn E2 mechanism is inferred for these substrates. The cis- A nd trans-4-tert-butylcyclohexyl bromides show a preference for the elimination of the cis isomer (kcis/ax/ktrans/eq = 10). Rate and isotopic labeling studies are consistent with a trans-diaxial E2 elimination via trisolvated monomer for the cis isomer and a carbenoid mechanism via disolvated monomer for the trans isomer. Vicinal haloethers show substrate-dependent reactivities, affording alkynes and enol ethers. trans-1-Bromo-2-methoxycyclohexane provides enol ether 1-methoxycyclohexene, while trans-1-bromo-2-methoxycyclooctane provides dimeric products consistent with fleeting cycloocta-1,2-diene (cyclic allene), which was fully characterized as two conformers.
Effect on conformation on proton affinities of stereoisomeric ethers
Denekamp,Etinger,Fokkens,Khaselev,Mandelbaum,Nibbering
, p. 1174 - 1178 (2007/10/03)
The proton affinity (PA) of cis-4-tert-butylcyclohexyl methyl ether with an axial methoxy group is higher by ~ 0.1 kcal mol-1 (1 kcal = 4.184 kJ) than the trans isomer with the equatorial ether group. The gas-phase basicity shows a similar smal
