Synthesis of Differentially Substituted 2-Aminoimidazolidines via a Microwave-Assisted Tandem Staudinger/Aza-Wittig Cyclization
摘要:
A new route for the construction of 2-aminoimidazolidines including analogues of the alpha(2) adrenergic agonist drug clonidine is elaborated. The key step is an intramolecular microwave-assisted Staudinger/aza-Wittig cyclization of an in situ generated urea intermediate (formed by the reaction of beta-amino azide and isocyanate) upon treatment with Bu3P or polymer-supported phosphine reagent, allowing the introduction of various substituents at the N1 and the 2-amino function. Furthermore, a useful one-pot Staudinger/aza-Wittig/Buchwald-Hartwig protocol leading to bicyclic guanidines has been elaborated.
2-(2-Pyridyldithio-3-butenyl) glycosides react with carbohydrate-based thiols in a two-step process involving sulfenyl transfer followed by desulfurative 2,3-allylic rearrangement, promoted by either triphenylphosphine or silver nitrate, to give novel saccharide mimetics. In an alternative embodiment of the same chemistry anomeric thiols are coupled with carbohydrates derivatized in the form of 2-
Cobalt-Porphyrin-Catalysed Intramolecular Ring-Closing C−H Amination of Aliphatic Azides: A Nitrene-Radical Approach to Saturated Heterocycles
作者:Petrus F. Kuijpers、Martijn J. Tiekink、Willem B. Breukelaar、Daniël L. J. Broere、Nicolaas P. van Leest、Jarl Ivar van der Vlugt、Joost N. H. Reek、Bas de Bruin
DOI:10.1002/chem.201700358
日期:2017.6.12
Cobalt porphyrin catalysed intramolecular ring-closing C-H bond amination enables direct synthesis of various N-heterocycles from aliphatic azides. Pyrrolidines, oxazolidines imidazolidines, isoindolines and tetrahydroisoquinoline can be obtained in good to excellent yields in a single reaction step with an air and moisture stable catalyst. Kinetic studies of the reaction in combination with DFT calculations
One-Pot Synthesis of Macrocycles by a Tandem Three-Component Reaction and Intramolecular [3+2] Cycloaddition
作者:Tracey Pirali、Gian Cesare Tron、Jieping Zhu
DOI:10.1021/ol061782p
日期:2006.8.1
substrates, a programmed sequence involving an alpha-isocyano acetamide-based three-component reaction followed by a copper-catalyzedintramolecular [3+2] cycloaddition of alkyne and azide took place to afford complex macrocycles in moderate to good yields. One macrocycle and two heterocycles were produced with concurrent formation of five chemical bonds in this operationally simple process.
Pyrazolopyrimidines, a process for their preparation and their use as medicine
申请人:Merz Pharma GmbH & Co. KGaA
公开号:EP2085398A1
公开(公告)日:2009-08-05
The invention relates to pyrazolopyrimidine derivatives of Formula I
wherein
R1 represents chloro or bromo;
A represents
as well as their pharmaceutically acceptable salts. The invention further relates to a process for the preparation of such compounds. The compounds of the invention are mGluR5 modulators and are therefore useful for the control and prevention of acute and/or chronic neurological disorders.
PYRAZOLOPYRIMIDINES, A PROCESS FOR THEIR PREPARATION AND THEIR USE AS MEDICINE
申请人:Henrich Markus
公开号:US20110003820A1
公开(公告)日:2011-01-06
The invention relates to pyrazolopyrimidine derivatives as well as their pharmaceutically acceptable salts. The invention further relates to a process for the preparation of such compounds. The compounds of the invention are mGluR5 modulators and are therefore useful for the control and prevention of acute and/or chronic neurological disorders.