Eclipsed Conformation of the Exocyclic N−CH2 Bond in N-Neopentylpiperidines and the Stereodynamic Consequences As Studied by Dynamic NMR Spectroscopy and Molecular Mechanics Calculations
摘要:
The dynamic stereochemistry of a range of N-neopentylpiperidines 1 with an eclipsed N-CH2-t-Bu bond is compared with that of the corresponding range of N-ethylpiperidines 2 with a gauche N-CH2Me bond. By using dynamic NMR spectroscopy, the relative importance of ring inversion, exocyclic bond rotation, and nitrogen inversion are elucidated and barriers are reported and discussed. Minor populations of the neopentyl-axial-eclipsed conformation are detected directly and identified with the help of molecular mechanics calculations. The corresponding N-alkylpyrrolidines are also reported.
Antinociceptive Effects of 1-Acyl-4-dialkylaminopiperidine and 1-Alkyl-4-dialkylaminopiperidine in Mice: Structure-Activity Relation Study of Matrine-Type Alkaloids.
Mild and chemoselective catalytic deprotection of ketals and acetals using cerium(IV) ammonium nitrate
作者:Ali Ates、Arnaud Gautier、Bernard Leroy、Jean-Marc Plancher、Yannick Quesnel、Jean-Christophe Vanherck、István E Markó
DOI:10.1016/j.tet.2003.03.002
日期:2003.11
Cerium(IV) ammonium nitrate (CAN) is a powerful, though mild, reagent for the efficient and selective removal of a range of ketals and acetals. This novel deprotection method requires only catalytic amounts of CAN and tolerates a variety of functional and protecting groups. Mechanistic insights suggest that the Ce(IV) salts act as unique Lewis acids and not as redox active species.
Remarkably efficient deprotection of cyclic acetals and ketals
作者:Ali Ates、Arnaud Gautier、Bernard Leroy、Jean-Marc Plancher、Yannick Quesnel、István E Markó
DOI:10.1016/s0040-4039(99)00013-1
日期:1999.2
A simple and mild procedure for the efficientdeprotection of cyclic acetals and ketals, using cerium ammonium nitrate (CAN) is reported. The method tolerates a range of functional and protecting groups and is suitable for acid-labile substrates.
The present invention relates to compounds which bind to the NR1 H4 receptor (FXR) and act as agonists of FXR. The invention further relates to the use of the compounds for the preparation of a medicament for the treatment of diseases and/or conditions through binding of said nuclear receptor by said compounds and to a process for the synthesis of said compounds.
This invention relates to benzimidazoles, pyridylimidazoles and related bicyclic heteroaryl compounds, all of which may be described by of Formula I
The invention is particularly related to such compounds that bind with high selectivity and high affinity to the benzodiazepine site of GABA
A
receptors. This invention also relates to pharmaceutical compositions comprising such compounds and to the use of such compounds in treatment of certain central nervous system (CNS) diseases. Novel processes for preparing compounds of Formula I are disclosed.
This invention also relates to the use of benzimidazoles, pyridylimidazoles and related bicyclic heteroaryl compounds of Formula I in combination with one or more other CNS agents to potentiate the effects of the other CNS agents. Additionally this invention relates to the use such compounds as probes for the localization of GABA
A
receptors in tissue sections.
The present invention relates to compounds of formula (1) which bind to the NR1H4 receptor (FXR) and act as agonists of FXR. The invention further relates to the use of the compounds for the preparation of a medicament for the treatment of diseases and/or conditions through binding of said nuclear receptor by said compounds and to a process for the synthesis of said compounds.