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Münchnone
Münchnone (synonyms: 1,3-oxazolium-5-oxide; 1,3-oxazolium-5-olate; anhydro-5-hydroxy-1,3-oxazolium hydroxide; 5-hydroxy-1,3-oxazolium hydroxide, inner salt; oxido-oxazolium) is a mesoionic heterocyclic aromatic chemical compound, with the molecular formula C3H3NO2. The name refers to the city of Munich, Germany (), where the compound and its derivatives were first discovered and studied. Synthesis and reactivity The first preparation of a münchnone derivative was reported in 1959 by Lawson & Miles by cyclodehydration of 2-pyridone-''N''-acetic acid with acetic anhydride. The azomethine ylide reactivity of münchnones, and their reaction with alkynes in the synthesis of pyrroles, was first published by Huisgen et al. The Huisgen group followed up with a thorough investigation of the chemical properties, reactivity, and utility of münchnones towards the synthesis of many other products.Gribble, G. W. In ''Oxazoles: Synthesis, Reactions, and Spectroscopy'', A; Palmer, D. C., Ed.; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montréalone
Montréalone (synonyms: montrealone, phospha-münchnone) is a mesoionic heterocyclic compound, heterocyclic chemical compound. It is named for the city of Montreal, Montréal, Canada, which is the location of McGill University, where it was first discovered. Structure The montréalone parent structure, parent compound has been studied theoretically,Krenske, E. H.; Houk, K. N.; Arndtsen, B. A.; St. Cyr, D. J., Cyclic 1,3-Dipoles or Acyclic Phosphonium Ylides? Electronic Characterization of "Montréalones". ''J. Am. Chem. Soc.'' 2008, ''130'', 10052. () and is unlikely to exist as a stable species. structural analog, Analogs bearing multiple substituents display chemical stability, stability suitable for synthesis, isolation, and characterization.St-Cyr, D. J.; Morin, M. S. T.; Belanger-Gariepy, F.; Arndtsen, B. A.; Krenske, E. H.; Houk, K. N., Phospha-Münchnones: Electronic Structures and 1,3-Dipolar Cycloadditions. ''J. Org. Chem.'' 2010, ''75'', 4261. () Substituted montréalon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azomethine Ylide
Azomethine ylides are nitrogen-based 1,3-dipoles, consisting of an iminium ion next to a carbanion. They are used in 1,3-dipolar cycloaddition reactions to form five-membered heterocycles, including pyrrolidines and pyrrolines. These reactions are highly stereo- and regioselective, and have the potential to form four new contiguous stereocenters. Azomethine ylides thus have high utility in total synthesis, and formation of chiral ligands and pharmaceuticals. Azomethine ylides can be generated from many sources, including aziridines, imines, and iminiums. They are often generated ''in situ'', and immediately reacted with dipolarophiles. Structure The resonance structures below show the 1,3-dipole contribution, in which the two carbon atoms adjacent to the nitrogen have a negative or positive charge. The most common representation of azomethine ylides is that in which the nitrogen is positively charged, and the negative charge is shared between the two carbon atoms. The relati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrole
Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4 H4 NH. It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., ''N''-methylpyrrole, C4H4NCH3. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme. Pyrroles are components of more complex macrocycles, including the porphyrinogens and products derived therefrom, including porphyrins of heme, the chlorins, bacteriochlorins, and chlorophylls. Properties Pyrrole is a colorless volatile liquid that darkens readily upon exposure to air, and is usually purified by distillation immediately before use. Pyrrole has a nutty odor. Pyrrole is a 5-membered aromatic heterocycle, like furan and thiophene. Unlike furan and thiophene, it has a dipole in which the positive end lies on the side of the heteroatom, with a dipole moment of 1.58 D. In CDCl3, it has ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoionic
In chemistry, mesoionic compounds are one in which a heterocyclic structure is dipolar and where both the negative and the positive charges are delocalized. A completely uncharged structure cannot be written and mesoionic compounds cannot be represented satisfactorily by any one mesomeric structure. Mesoionic compounds are a subclass of betaines. Examples are sydnones and sydnone imines (e.g. the stimulant mesocarb), münchnones, and mesoionic carbenes. The formal positive charge is associated with the ring atoms and the formal negative charge is associated either with ring atoms or an exocyclic nitrogen or other atom. These compounds are stable zwitterionic compounds and belong to nonbenzenoid aromatics. See also * Mesomeric betaine Mesomeric betaines are dipolar heterocyclic compounds in which both the negative and the positive charges are delocalized. Examples are mesoionic compounds and heteropentalenes (e.g. diazapentalenes). Heteropentalenes are not mesoionic In c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sydnone Imine
Sydnone imine is a mesoionic heterocyclic aromatic chemical compound. Sydnone imine is the imine of sydnone where the keto functional group of sydnone (=O) has been replaced with an imine (=NH) group. A sydnone imine substructure can be found in the drugs feprosidnine, mesocarb, molsidomine, ciclosidomine, and linsidomine. Chemical structure See also * Montréalone * Münchnone Münchnone (synonyms: 1,3-oxazolium-5-oxide; 1,3-oxazolium-5-olate; anhydro-5-hydroxy-1,3-oxazolium hydroxide; 5-hydroxy-1,3-oxazolium hydroxide, inner salt; oxido-oxazolium) is a mesoionic heterocyclic aromatic chemical compound, with the molecula ... * Sydnone External links IUPAC Goldbook entryDictionary of Organic Compounds Simple aromatic rings Oxadiazoles Imines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sydnone
Sydnones are mesoionic heterocyclic chemical compounds possessing a 1,2,3-oxadiazole core with a keto group in the 5 position. Like other mesoionic compounds they are di-polar, possessing both positive and negative charges which are delocalized across the ring. Recent computational studies have indicated that sydnones and other similar mesoionic compounds are nonaromatic, "though well-stabilized in two separate regions by electron and charge delocalization." Sydnones are heterocyclic compounds named after the city of Sydney, Australia. A sydnone imine in which the keto group of sydnone (=O) has been replaced with an imino (=NH) group can be found as a substructure in the stimulant drugs feprosidnine and mesocarb. Discovery Sydnone was first prepared in 1935 by Earl & Mackney by cyclodehydration of N-Nitroso-N-phenylglycine ''N''-Phenylglycine is an organic compound with the formula C6H5NHCH2CO2H. This white solid achieved fame as the industrial precursor to indigo dye. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxazolone
Oxazolone is a chemical compound and functional group, with the molecular formula C3H3NO2. It was named in-line with the Hantzsch–Widman nomenclature and is part of a large family of oxazole based compounds. There are a total of 5 structural isomers of oxazolone; 3 according to the location of the carbonyl group and 2 more according to the location of the double bound C=X (with X= N or C): *2-(3''H'')oxazolone *2-(5''H'')oxazolone *4-(5''H'')-oxazolone *5-(2''H'')-oxazolone *5-(4''H'')-oxazolone The 4-oxazolone motif, which is also formally a lactam, is present in a number of drugs (fenozolone, thozalinone, cyclazodone, reclazepam etc.). Substituted 5-oxazolones may also be regarded as the cyclization products of ''N''-acyl α-amino acids, making them lactones, and are sometimes referred to as azlactones. See also * Münchnone * Oxazole Oxazole is the parent compound for a vast class of heterocyclic aromatic organic compounds. These are azoles with an oxygen and a nitro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Chemical Compounds With Unusual Names
IUPAC nomenclature, Chemical nomenclature, replete as it is with chemical compound, compounds with complex names, is a wikt:repository, repository for some names that may be considered unusual. A browse through the ''Physical Constants of Organic Compounds'' in the ''CRC Handbook of Chemistry and Physics'' (a fundamental resource) will reveal not just the whimsical work of chemists, but the sometimes peculiar compound names that occur as the consequence of simple Contrast (linguistics), juxtaposition. Some names derive legitimately from their chemical makeup, from the geographic region where they may be found, the plant or animal species from which they are isolated or the name of the discoverer. Some are given intentionally unusual trivial names based on their structure, a notable property or at the whim of those who first isolate them. However, many trivial names predate formal naming conventions. Trivial names can also be ambiguous or carry different meanings in different indust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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