Hydrazine-mediated cyclization of Ugi products to synthesize novel 3-hydroxypyrazoles
نویسندگان
چکیده
منابع مشابه
Various cyclization scaffolds by a truly Ugi 4-CR.
Efficient access to a large chemical space based on new scaffolds with defined 3D conformations and highly variable in the side chains is needed to find novel functional materials. Four heterocyclic scaffolds based on a four component Ugi reaction of α-amino acids, oxo components, isocyanides and primary or secondary amines suitably functionalized are described. A handful of examples are descri...
متن کاملA copper-mediated cyclization reaction of hydrazine with enediynones providing pyrazolo[1,5-a]pyridines.
2,7-Disubstituted pyrazolo[1,5-a]pyridines were synthesized in good chemical yields by the reaction of enediynones with hydrazine, followed by addition of copper chloride. This reaction can tolerate many functional groups.
متن کاملHydrazine-mediated strongly coupled Re(CO)3 dimers.
Dimeric metal complexes can often exhibit coupling interactions via bridging ligands. In this report, we present two Re(CO)3 dimers, where the metals are linked via a bis(pyca) hydrazine (pyca = pyridine-2-carbaldehyde imine) Schiff base ligand. For the dimeric compounds 4 and 5, we observe strong coupling across the dimer as measured by cyclic voltammetry: ∼480 mV separations between the first...
متن کاملPalladium-catalyzed oxidative cyclization of aniline-tethered alkylidenecyclopropanes with O2: a facile protocol to selectively synthesize 2- and 3-vinylindoles.
A novel palladium-catalyzed oxidative cyclization of aniline-tethered alkylidenecyclopropanes using molecular oxygen as the terminal oxidant through β-carbon elimination of aminopalladation intermediates is disclosed. The reaction opens up an effective way to obtain a series of 2- and 3-vinylindoles which are important synthetic intermediates in many natural indole derivatives.
متن کاملSELECTIVE CYCLIZATION AND IS OMERIZATION OF 3-PROPARGYLTHIO- 1,2,4- BENZOTRIAZINE TO THIAZOLO [2,3-C] [1,2,4] BENZOTRIAZINE
The method cited in the literature for synthesis of 1,2- dihydro 3- thioxo - 1,2,4- benzotriazine 1 was improved .1 was condensed with propargyl bromide to afford 3 - propargylthio – 1,2,4 -benzotriazine 5. Transformation of this compound to 9H-3- methylthiazolo [2,3-c] [1,2,4] benzotriazine ( 3, R = Me) was performed in the presence of Na O Me / MeOH . Orientation of this selective cy...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Tetrahedron Letters
سال: 2012
ISSN: 0040-4039
DOI: 10.1016/j.tetlet.2012.03.033