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W.E. Doering
William von Eggers Doering (June 22, 1917 – January 3, 2011) was the Mallinckrodt Professor of Chemistry at Harvard University. Before Harvard, he taught at Columbia (1942–1952) and Yale (1952–1968). Doering was born in Fort Worth, Texas to academics Carl Rupp Doering and Antoinette Mathilde von Eggers, both of whom were professors at Texas Christian University. His maternal great-uncle was the prominent German financier and economist Hjalmar Schacht, sometime President of the ''Reichsbank'' and cabinet minister in Nazi Germany. Doering was an undergraduate at Harvard University, where he took courses with some of the leading organic chemists at the time, including Louis Fieser and Paul Bartlett. He stayed at Harvard for his graduate education, where he studied catalytic hydrogenation under Reginald Linstead, completing his PhD in 1943. Before beginning his independent career, he became famous for completing a (formal) quinine total synthesis with Robert Burns Woodward a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fort Worth, Texas
Fort Worth is the List of cities in Texas by population, fifth-largest city in the U.S. state of Texas and the List of United States cities by population, 13th-largest city in the United States. It is the county seat of Tarrant County, Texas, Tarrant County, covering nearly into four other counties: Denton County, Texas, Denton, Johnson County, Texas, Johnson, Parker County, Texas, Parker, and Wise County, Texas, Wise. According to a 2022 United States census estimate, Fort Worth's population was 958,692. Fort Worth is the city in the Dallas–Fort Worth metroplex, Dallas–Fort Worth–Arlington metropolitan area, which is the List of metropolitan statistical areas, fourth most populous metropolitan area in the United States. The city of Fort Worth was established in 1849 as an army outpost on a bluff overlooking the Trinity River (Texas), Trinity River. Fort Worth has historically been a center of the Texas Longhorn cattle trade. It still embraces its Western heritage and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Texas Christian University
Texas Christian University (TCU) is a private research university in Fort Worth, Texas. It was established in 1873 by brothers Addison and Randolph Clark as the Add-Ran Male & Female College. It is affiliated with the Christian Church (Disciples of Christ). The campus is located on about 3 miles (5 km) from downtown Fort Worth. TCU is affiliated with, but not governed by, the Disciples of Christ. The university consists of eight constituent colleges and schools and has a classical liberal arts curriculum. It is classified among "R2: Doctoral Universities – High research activity". TCU's mascot is Superfrog, based on the Texas state reptile; the horned frog. For most varsity sports, TCU competes in the Big 12 conference of the NCAA's Division I. As of Fall 2021, the university enrolls around 11,938 students, with 10,222 being undergraduates. History Origins in Fort Worth, 1869–1873 The East Texas brothers Addison and Randolph Clark, with the support of their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fulvalene
Fulvalene (bicyclopentadienylidene) is the member of the fulvalene family with the molecular formula C10H8. It is of theoretical interest as one of the simplest non-benzenoid conjugated hydrocarbons. Fulvalene is an unstable isomer of the more common benzenoid aromatic compounds naphthalene and azulene. Fulvalene consists of two 5-membered rings, each with two double bonds, joined by yet a fifth double bond. It has D2h symmetry. History An earlier attempt at synthesis of fulvalene in 1951 by Pauson and Kealy resulted in the accidental discovery of ferrocene. Its synthesis was first reported in 1958 by E. A. Matzner, working under William von Eggers Doering. In this method, cyclopentadienyl anion is coupled with iodine to the dihydrofulvalene. Double deprotonation of dihydrofulvalene with ''n''-butyllithium gives the dilithio derivative, which oxidizes with oxygen. Fulvalene was spectroscopically observed at from photolysis of diazocyclopentadiene, which induces dimer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichlorocarbene
Dichlorocarbene is the reactive intermediate with chemical formula CCl2. Although this chemical species has not been isolated, it is a common intermediate in organic chemistry, being generated from chloroform. This bent diamagnetic molecule rapidly inserts into other bonds. Preparation Dichlorocarbene is most commonly generated by reaction of chloroform and a base such as potassium ''tert''-butoxide or aqueous sodium hydroxide. A phase transfer catalyst, for instance benzyltriethylammonium bromide, facilitates the migration of the hydroxide in the organic phase. :HCCl3 + NaOH → CCl2 + NaCl + H2O Other reagents and routes Another precursor to dichlorocarbene is ethyl trichloroacetate. Upon treatment with sodium methoxide it releases CCl2. Phenyl(trichloromethyl)mercury decomposes thermally to release CCl2. :PhHgCCl3 → CCl2 + PhHgCl Dichlorodiazirine, which is stable in the dark, decomposes into dichlorocarbene and nitrogen via photolysis. Dichlorocarbene can also be ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbene
In organic chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The general formula is or where the R represents substituents or hydrogen atoms. The term "carbene" may also refer to the specific compound , also called methylene, the parent hydride from which all other carbene compounds are formally derived. Carbenes are classified as either singlets or triplets, depending upon their electronic structure. Most carbenes are very short lived, although persistent carbenes are known. One well-studied carbene is dichlorocarbene , which can be generated ''in situ'' from chloroform and a strong base. Structures and bonding The two classes of carbenes are singlet and triplet carbenes. Singlet carbenes are spin-paired. In the language of valence bond theory, the molecule adopts an sp2 hybrid structure. Triplet carbenes have two unpaired electrons. Most carbenes have a nonlinear triplet ground state, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cope Rearrangement
The Cope rearrangement is an extensively studied organic reaction involving the ,3sigmatropic rearrangement of 1,5-dienes. It was developed by Arthur C. Cope and Elizabeth Hardy. For example, 3-methyl-hexa-1,5-diene heated to 300 °C yields hepta-1,5-diene. The Cope rearrangement causes the fluxional states of the molecules in the bullvalene family. Mechanism The Cope rearrangement is the prototypical example of a concerted sigmatropic rearrangement. It is classified as a ,3sigmatropic rearrangement with the Woodward–Hoffmann symbol π2s+σ2s+π2s.html" ;"title="sub>π2s+σ2s+π2s">sub>π2s+σ2s+π2sand is therefore thermally allowed. It is sometimes useful to think of it as going through a transition state energetically and structurally equivalent to a diradical, although the diradical is not usually a true intermediate (potential energy minimum). The chair transition state illustrated here is preferred in open-chain systems (as shown by the Doering-Roth experime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropylium Cation
In organic chemistry, the tropylium ion or cycloheptatrienyl cation is an aromatic species with a formula of 7H7sup>+. Its name derives from the molecule tropine from which cycloheptatriene (tropylidene) was first synthesized in 1881. Salts of the tropylium cation can be stable, even with nucleophiles of moderate strength e.g., tropylium tetrafluoroborate and tropylium bromide (''see below''). Its bromide and chloride salts can be made from cycloheptatriene and bromine or phosphorus pentachloride, respectively. It is a regular heptagonal, planar, cyclic ion. It has 6 π-electrons (4''n'' + 2, where ''n'' = 1), which fulfills Hückel's rule of aromaticity. It can coordinate as a ligand to metal atoms. The structure shown is a composite of seven resonance contributors in which each carbon atom carries part of the positive charge. History In 1891 G. Merling obtained a water-soluble bromine-containing compound from the reaction of cycloheptatriene and bromine. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Chemical Society
The American Chemical Society (ACS) is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 155,000 members at all degree levels and in all fields of chemistry, chemical engineering, and related fields. It is one of the world's largest scientific societies by membership. The ACS is a 501(c)(3) non-profit organization and holds a congressional charter under Title 36 of the United States Code. Its headquarters are located in Washington, D.C., and it has a large concentration of staff in Columbus, Ohio. The ACS is a leading source of scientific information through its peer-reviewed scientific journals, national conferences, and the Chemical Abstracts Service. Its publications division produces over 60 scholarly journals including the prestigious ''Journal of the American Chemical Society'', as well as the weekly trade magazine '' Chemical & Enginee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Burns Woodward
Robert Burns Woodward (April 10, 1917 – July 8, 1979) was an American organic chemist. He is considered by many to be the most preeminent synthetic organic chemist of the twentieth century, having made many key contributions to the subject, especially in the synthesis of complex natural products and the determination of their molecular structure. He also worked closely with Roald Hoffmann on theoretical studies of chemical reactions. He was awarded the Nobel Prize in Chemistry in 1965. Early life and education Woodward was born in Boston, Massachusetts, on April 10, 1917. He was the son of Margaret Burns (an immigrant from Scotland who claimed to be a descendant of the poet, Robert Burns) and her husband, Arthur Chester Woodward, himself the son of Roxbury apothecary, Harlow Elliot Woodward. His father was one of the many victims of the 1918 influenza pandemic of 1918. From a very early age, Woodward was attracted to and engaged in private study of chemistry while he att ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinine Total Synthesis
The total synthesis of quinine, a naturally-occurring antimalarial drug, was developed over a 150-year period. The development of synthetic quinine is considered a milestone in organic chemistry although it has never been produced industrially as a substitute for natural occurring quinine. The subject has also been attended with some controversy: Gilbert Stork published the first stereoselective total synthesis of quinine in 2001, meanwhile shedding doubt on the earlier claim by Robert Burns Woodward and William Doering in 1944, claiming that the final steps required to convert their last synthetic intermediate, quinotoxine, into quinine would not have worked had Woodward and Doering attempted to perform the experiment. A 2001 editorial published in ''Chemical & Engineering News'' sided with Stork, but the controversy was eventually laid to rest once and for all when Williams and coworkers successfully repeated Woodward's proposed conversion of quinotoxine to quinine in 2007. Chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Boston Globe
''The Boston Globe'' is an American daily newspaper founded and based in Boston, Massachusetts. The newspaper has won a total of 27 Pulitzer Prizes, and has a total circulation of close to 300,000 print and digital subscribers. ''The Boston Globe'' is the oldest and largest daily newspaper in Boston. Founded in 1872, the paper was mainly controlled by Irish Catholic interests before being sold to Charles H. Taylor and his family. After being privately held until 1973, it was sold to ''The New York Times'' in 1993 for $1.1billion, making it one of the most expensive print purchases in U.S. history. The newspaper was purchased in 2013 by Boston Red Sox and Liverpool owner John W. Henry for $70million from The New York Times Company, having lost over 90% of its value in 20 years. The newspaper has been noted as "one of the nation's most prestigious papers." In 1967, ''The Boston Globe'' became the first major paper in the U.S. to come out against the Vietnam War. The paper's 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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