74454-44-7Relevant academic research and scientific papers
A clean and selective radical homocoupling employing carboxylic acids with titania photoredox catalysis
Manley, David W.,Walton, John C.
supporting information, p. 5394 - 5397 (2015/02/19)
A titania photoredox catalysis protocol was developed for the homocoupling of C-centered radicals derived from carboxylic acids. Intermolecular reactions were generally efficient and selective, furnishing the desired dimers in good yields under mild neutral conditions. Selective cross-coupling with two acids proved unsuccessful. An intra-molecular adaptation enabled macrocycles to be prepared, albeit in modest yields. (Chemical Equation Presented).
Synthesis of 7-Azadispiropentadecane and 6-Azadispirotetradecane
Wagner, E. R.,Matthews, D. P.
, p. 1289 - 1291 (2007/10/02)
Two new, hindered secondary amines, 7-azadispiropentadecane hydrochloride (1a) and 6-azadispirotetradecane hydrochloride (1b), have been prepared in four steps from 1-ethynylcyclohexylamine (2).The final thermal cyclization of 1-(2-(1-am
REDUCTION OF ORGANIC COMPOUNDS WITH LOW-VALENT NIOBIUM (NbCl5/NaAlH4)
Sato, Mitsuyoshi,Oshima, Koichiro
, p. 157 - 160 (2007/10/02)
Carbonyl compounds have been deoxygenatively dimerized to alkenes with the title reagent.Deoxygenation of epoxides to alkenes, reductive coupling of allylic and benzylic alcohols to hydrocarbons, and reduction of alkynes to alkenes are also described.
Diastereomeric Transition States. Relative Energies of the Chair and Boat Reaction Pathways in the Cope Rearrangement
Shea, Kenneth J.,Phillips, Richard B.
, p. 3156 - 3162 (2007/10/02)
Thermal rearrangement of dl- and meso-2,2'-bismethylenecyclopentane and 2,2'-bismethylenecyclohexane is reported.The rates of rearrangement permit independent measurement of the high- and low-energy conformations of the Cope rearrangement.The transition-state geometry for each diastereomer is uniquely defined as C2v (boat) for the meso isomer and C2h (chair) for the dl diastereomer.Correlation of these findings with available data from thermal rearrangement of 1,5-hexadiene establishes that bismethylenecycloalkanes are reasonable models for the isomeric transition states of sigmatropic rearrangements.The "characteristic" activation parameters of the Cope rearrangement, in particular the large negative entropy of activation, are consistent with the chair-like (C2h) transition state.The boat-like transition state (C2v), on the other hand, exhibits a slightly positive entropy of activation.Both reactions satisfy mechanistic criteria for concertedness.These results indicate that the entropy of activation does not provide a valid criteria of concertedness.Consideration of stereochemical results from a number of highly substituted derivatives of 1,5-dienes reveals that alternative transition-state geometries C2h (twist) and C2v (plane) are at substantially higher energy than the chair and do not, therefore, play an important role in sigmatropic rearrangement of conformationally flexible 1,5-dienes.
