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Paternò–Büchi Reaction
The Paternò–Büchi reaction, named after Emanuele Paternò and George Büchi, who established its basic utility and form, is a photochemical reaction, specifically a 2+2 photocycloaddition, which forms four-membered oxetane rings from an excited carbonyl and reacting with an alkene. : With substrates benzaldehyde and 2-methyl-2-butene the reaction product is a mixture of structural isomers: : Another substrate set is benzaldehyde and furan or heteroaromatic ketones and fluorinated alkenes. The alternative strategy for the above reaction is called the Transposed Paternò−Büchi reaction. See also *Aza Paternò−Büchi reaction - the aza-equivalent of the Paternò–Büchi reaction *Enone–alkene cycloadditions In organic chemistry, enone–alkene cycloadditions are a version of the +2cycloaddition This reaction involves an enone and alkene as substrates. Although the concerted photochemical +2cycloaddition is allowed, the reaction between enones and ... - photoch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emanuele Paternò
Emanuele Paternò, 9th Marquess of Sessa was an Italian chemist and is credited with the discovery of the Paternò–Büchi reaction. Biography He was born in Palermo in 1847 as the Marquess of Sessa, in a branch of the House of Paternò. He studied at the University of Palermo with Stanislao Cannizzaro. Scientific career In 1871 he became a lecturer at the University of Torino, but returned to Palermo the following year as Cannizzaro's successor. In 1892 he became a professor at the Sapienza University of Rome, University of Rome. His main area of research was photochemistry, and discovered the Paternò–Büchi reaction in 1909. The reaction was improved by George Büchi, its other namesake, in 1954. Political career Paternò was politically active. He served as the List of mayors of Palermo, Mayor of Palermo (1890–1892), and in 1890 he was appointed by King Victor Emmanuel III a member of the Senate of the Kingdom of Italy. He was later elected vice president (1904-1919 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furan
Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen atom. Chemical compounds containing such rings are also referred to as furans. Furan is a colorless, flammable, highly volatile liquid with a boiling point close to room temperature. It is soluble in common organic solvents, including alcohol, ether, and acetone, and is slightly soluble in water. Its odor is "strong, ethereal; chloroform-like". It is toxic and may be carcinogenic in humans. Furan is used as a starting point for other speciality chemicals. History The name "furan" comes from the Latin ''furfur'', which means bran. ( Furfural is produced from bran.) The first furan derivative to be described was 2-furoic acid, by Carl Wilhelm Scheele in 1780. Another important derivative, furfural, was reported by Johann Wolfgang Döbereiner in 1831 and characterised nine years later by John Stenhouse. Furan itself was first prepared by Heinrich Lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Reactions
A name reaction is a chemical reaction named after its discoverers or developers. Among the tens of thousands of organic reactions that are known, hundreds of such reactions are well-known enough to be named after people. Well-known examples include the Grignard reaction, the Sabatier reaction, the Wittig reaction, the Claisen condensation, the Friedel-Crafts acylation, and the Diels-Alder reaction. Books have been published devoted exclusively to name reactions;Alfred Hassner, C. Stumer. ''Organic syntheses based on name reactions''. Elsevier, 2002. Li, Jie Jack. ''Name Reactions: A Collection of Detailed Reaction Mechanisms''. Springer, 2003. the Merck Index, a chemical encyclopedia, also includes an appendix on name reactions. As organic chemistry developed during the 20th century, chemists started associating synthetically useful reactions with the names of the discoverers or developers; in many cases, the name is merely a mnemonic. Some cases of reactions that were not reall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Reactions
Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, photochemical reactions and redox reactions. In organic synthesis, organic reactions are used in the construction of new organic molecules. The production of many man-made chemicals such as drugs, plastics, food additives, fabrics depend on organic reactions. The oldest organic reactions are combustion of organic fuels and saponification of fats to make soap. Modern organic chemistry starts with the Wöhler synthesis in 1828. In the history of the Nobel Prize in Chemistry awards have been given for the invention of specific organic reactions such as the Grignard reaction in 1912, the Diels-Alder reaction in 1950, the Wittig reaction in 1979 and olefin metathesis in 2005. Classifications Organic chemistry has a strong tradition of naming a specific reac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photochemistry
Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible light (400–750 nm) or infrared radiation (750–2500 nm). In nature, photochemistry is of immense importance as it is the basis of photosynthesis, vision, and the formation of vitamin D with sunlight. Photochemical reactions proceed differently than temperature-driven reactions. Photochemical paths access high energy intermediates that cannot be generated thermally, thereby overcoming large activation barriers in a short period of time, and allowing reactions otherwise inaccessible by thermal processes. Photochemistry can also be destructive, as illustrated by the photodegradation of plastics. Concept Grotthuss–Draper law and Stark-Einstein law Photoexcitation is the first step in a photochemical process where the reactant is elevated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lu Shin Wong
Lu Shin Wong is a Senior Lecturer in the Department of Chemistry, University of Manchester, Department of Chemistry at University of Manchester, The University of Manchester. His research in general is based on industrial biotechnology and materials chemistry, specifically on nanofabrication and biocatalysis. Education Wong completed his Bachelor of Pharmacy in 1997 at University of Nottingham and later spent two years at University of Bradford pursuing a part time Postgraduate diploma in clinical pharmacy before moving to University of Southampton to read his Doctor of Philosophy degree on ''Development & application of UV-visible microspectrometry to solid phase organic chemistry'' which he successfully completed in 2005. His PhD was supervised by Mark Bradley. Research and career Upon graduation in 2005, Wong worked as a Postdoctoral researcher with Jason Micklefield at the Manchester Institute of Biotechnology investigating on the application of chemical biology and surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of The American Chemical Society
The ''Journal of the American Chemical Society'' is a weekly peer-reviewed scientific journal that was established in 1879 by the American Chemical Society. The journal has absorbed two other publications in its history, the ''Journal of Analytical and Applied Chemistry'' (July 1893) and the ''American Chemical Journal'' (January 1914). It covers all fields of chemistry. Since 2021, the editor-in-chief is Erick M. Carreira (ETH Zurich). In 2014, the journal moved to a hybrid open access publishing model. Abstracting and indexing The journal is abstracted and indexed in Chemical Abstracts Service, Scopus, EBSCO databases, ProQuest databases, Index Medicus/MEDLINE/PubMed, and the Science Citation Index Expanded. According to the ''Journal Citation Reports'', the journal has a 2021 impact factor of 16.383. Editors-in-chief The following people are or have been editor-in-chief: * 1879–1880 – Hermann Endemann * 1880–1881 – Gideon E. Moore * 1881–1882 – Hermann Endemann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enone–alkene Cycloadditions
In organic chemistry, enone–alkene cycloadditions are a version of the +2cycloaddition This reaction involves an enone and alkene as substrates. Although the concerted photochemical +2cycloaddition is allowed, the reaction between enones and alkenes is stepwise and involves discrete diradical intermediates. History In 1908, it was reported that exposure of carvone to "Italian sunlight" for one year gives carvone- camphor. Subsequent investigations demonstrated the utility of the photochemical +2cycloaddition of enones to alkenes. Mechanism In spite of the stepwise, radical mechanism, both stereoselective intra- and intermolecular variants have emerged. Cyclic enones are employed, otherwise competitive cis-trans isomerization ensues. The mechanism of +2photocyclization is proposed to begin with photoexcitation of the enone to a singlet excited state. The singlet state is typically very short lived, and decays by intersystem crossing to the triplet state. At this point, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aza Paternò−Büchi Reaction
Aza Paternò−Büchi reaction involves an ππ* excited state of alkene reacting with a ground state imine. This strategy was developed by the laboratory Sivaguru and co-workers to overcome the shortcomings involving direct excitation of imines. Traditionally addition of excited imines to carbon-carbon double bonds involves making the imines as part of a carbocycle. References {{DEFAULTSORT:Aza Paternò-Büchi reaction Organic reactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transposed Paternò−Büchi Reaction
The transposed Paternò−Büchi reaction involves a ππ* excited state of alkene reacting with a ground state carbonyl In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a ... functionality. This is reversal of the traditional Paternò−Büchi reaction where an excited carbonyl group reacts with a ground state alkene. This strategy was first reported by Sivaguru and co-workers with reaction of enamides. References {{DEFAULTSORT:Transposed Paterno-Buchi reaction Organic reactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Isomers
In chemistry, a structural isomer (or constitutional isomer in the IUPAC nomenclature) of a compound is another compound whose molecule has the same number of atoms of each element, but with logically distinct bonds between them. The term metamer was formerly used for the same concept. For example, butanol , methyl propyl ether , and diethyl ether have the same molecular formula but are three distinct structural isomers. The concept applies also to polyatomic ions with the same total charge. A classical example is the cyanate ion and the fulminate ion . It is also extended to ionic compounds, so that (for example) ammonium cyanate and urea are considered structural isomers,William F. Bynum, E. Janet Browne, Roy Porter (2014): ''Dictionary of the History of Science''. 530 pages. and so are methylammonium formate and ammonium acetate . Structural isomerism is the most radical type of isomerism. It is opposed to stereoisomerism, in which the atoms and bonding scheme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Büchi
George Hermann Büchi (August 1, 1921 – August 28, 1998) was a Swiss organic chemist and professor at the Massachusetts Institute of Technology. "Paternò's reaction", known since the early twentieth century, was renamed to the "Paternò–Büchi reaction The Paternò–Büchi reaction, named after Emanuele Paternò and George Büchi, who established its basic utility and form, is a photochemical reaction, specifically a 2+2 photocycloaddition, which forms four-membered oxetane rings from an excit ..." based on enhancements made to it by Büchi's research group. Büchi died at the age of 77 of heart failure while hiking with his wife in Switzerland. References 1921 births 1998 deaths Organic chemists Massachusetts Institute of Technology faculty Members of the United States National Academy of Sciences Swiss expatriates in the United States {{chemist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
