Synthesis of bridgehead nitrogen heterocycles
نویسندگان
چکیده
منابع مشابه
Bridgehead nitrogen heterocycles which contain the quinazoline moiety -- synthesis and cycloaddition of 1,2-dihydroquinazoline 3-oxides.
A novel synthesis of 1,2-disubstituted 1,2-dihydroquinazoline 3-oxides 8 and the first ever examples of 1,3-dipolar trapping of these nitrones to homonuclear dipolarophiles is described. The new dipoles 8 reacted with N-methyl maleimide, generating diastereomeric adducts 14-16. In the reaction between 8 and dimethyl acetylenedicarboxylate, primary cycloadducts 17 and/or stable rearrangement pro...
متن کاملI. New Cycloadditions for the Synthesis of Nitrogen Heterocycles
Alkyliminoacetonitrile derivatives were investigated as dienophiles in the Diels-Alder reaction. These activated imines react with dienes in intramolecular [4+2] cycloadditions to provide products with either the quinolizidine or indolizidine ring system, depending on the length of the tether connecting diene and dienophile. Quinolizidine cycloadducts are formed in good yield and with high ster...
متن کامل2-Iodoisatogens: versatile intermediates for the synthesis of nitrogen heterocycles.
A Cu-promoted cyclization of 2-nitrophenyl iodoacetylenes provides a direct route to a range of 2-iodoisatogens. These compounds represent useful intermediates for the late-stage elaboration of the C-I bond to furnish isatins and a range of alternative heterocyclic products.
متن کاملSynthesis of Nitrogen Heterocycles Using Samarium(II) Iodide.
Nitrogen heterocycles represent vital structural motifs in biologically-active natural products and pharmaceuticals. As a result, the development of new, convenient and more efficient processes to N-heterocycles is of great interest to synthetic chemists. Samarium(II) iodide (SmI₂, Kagan's reagent) has been widely used to forge challenging C-C bonds through reductive coupling reactions. Histori...
متن کاملA general and efficient five-step one-pot procedure leading to nitrogen-bridgehead heterocycles containing an imidazole ring.
A very simple annulation reaction was designed, allowing an imidazole moiety to be fused onto a range of pyridine-based derivatives. The methodology consists of an activation step via the formation of a pyridinium salt to increase the electrophilicity of the pyridine ring, followed by a cascade reaction triggered by a nucleophilic attack of the iminium moiety. Depending on the pyridinium salt, ...
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: Journal of Heterocyclic Chemistry
سال: 1980
ISSN: 0022-152X,1943-5193
DOI: 10.1002/jhet.5570170105