Stereoselective reductions of substituted cyclohexyl and cyclopentyl carbon-nitrogen .pi. systems with hydride reagents
作者:Robert O. Hutchins、Wei Yang Su、Ramachandran Sivakumar、Frank Cistone、Yuriy P. Stercho
DOI:10.1021/jo00168a009
日期:1983.10
BF<sub>3</sub>-Mediated Additions of Organolithiums to Ketimines: X-ray Crystal Structures of BF<sub>3</sub>−Ketimine Complexes
作者:Yun Ma、Emil Lobkovsky、David B. Collum
DOI:10.1021/jo0480895
日期:2005.3.1
Additions of lithium acetylides and n-BuLi to N-alkyl ketimines mediated by BF3-Et2O in THF afford hindered tert-alkylamines in moderate to good yields. Stereochemical results and crystal structures of three BF3-imine complexes suggest that allylic strain strongly influences conformation and may be an important determinant of reactivity and selectivity.
Conformational Analysis and Structural Elucidation of Spirocyclic Oxaziridines Using NMR, Crystallography, and Molecular Modeling
作者:Yoshinosuke Usuki、Yuguang Wang、Jeffrey Aube
DOI:10.1021/jo00129a050
日期:1995.12
The H-1 NMR spectra of spirocyclic oxaziridines derived from substituted cyclohexanones and benzylamines were studied. Depending on substitution and on stereochemistry, these compounds often exhibit a substantial upfield shift of the cyclohexyl methylene or methine protons with a 1,3-diaxial relationship to the oxaziridine N-substituent. This effect is ascribed to a conformation that places an aromatic group over the plane of the cyclohexane ring. This conformation has also been found in the solid state by X-ray crystallography and is supported by molecular mechanics calculations. The use of the effect in assigning stereochemistry to this series of compounds is discussed.
Reduction of Imines with Zinc Borohydride Supported on Silica Gel. Highly Stereoselective Synthesis of Substituted Cyclohexylamines
作者:Brindaban C. Ranu、Arunkanti Sarkar、Adinath Majee
DOI:10.1021/jo961736a
日期:1997.3.1
WROBEL, J. E.;GANEM, B., TETRAHEDRON LETT., 1981, 22, N 36, 3447-3450