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Turbo-Hauser Bases
''Turbo''-Hauser bases are amido magnesium halides that contain stoichiometric amounts of LiCl. These mixed Mg/Li amides of the type R2NMgCl⋅LiCl are used in organic chemistry as non-nucleophilic bases for metalation reactions of aromatic and heteroaromatic substrates. Compared to their LiCl free ancestors ''Turbo''-Hauser bases show an enhanced kinetic basicity, excellent regioselectivity, high functional group tolerance and a better solubility. Preparation Typically ''Turbo''-Hauser bases are prepared by treating an amine with a Grignard reagent and lithium chloride. In some cases they are prepared by treating a lithium amide with MgCl2: : : Common ''Turbo''-Hauser bases: R'2NH = ''i''Pr2NMgCl·LiCl (''i''Pr-''Turbo''-Hauser base), TMPMgCl·LiCl, TMP (''Turbo''-Hauser base or ''Knochel''-Hauser Base) Structure In solution, ''Turbo''-Hauser bases participate in temperature- and concentration-dependent equilibria. Diffusion-Ordered Spectroscopy (DOSY) show that at room ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hauser Base
Hauser bases, also called magnesium amide bases, are magnesium compounds used in organic chemistry as bases for metalation reactions. These compounds were first described by Charles R. Hauser in 1947. Compared with organolithium reagents, the magnesium compounds have more covalent, and therefore less reactive, metal-ligand bonds. Consequently, they display a higher degree of functional group tolerance and a much greater chemoselectivity. Generally, Hauser bases are used at room temperature while reactions with organolithium reagents are performed at low temperatures, commonly at −78 °C. Structure Solid state structure Like all Grignard dimers, Hauser bases derived from 2,2,6,6-tetramethylpiperidine (TMP) and HMDS are bridged by halides in the solid state. In contrast to Grignard reagents, dimeric amido bridged Hauser bases exist, too. All have one in common: they are bridged by less bulky amido ligands such as Et2N−, Ph3P=N− and ''i''Pr2N−. The displacem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isopropylmagnesium Chloride
Isopropylmagnesium chloride is an organometallic compound with the general formula (CH3)2HCMgCl. This highly flammable, colorless, and moisture sensitive material is the Grignard reagent derived from isopropyl chloride. It is commercially available, usually as a solution in tetrahydrofuran. This reagent is used to prepare Grignard reagents by transmetalation Transmetalation (alt. spelling: transmetallation) is a type of organometallic reaction that involves the transfer of ligands from one metal to another. It has the general form: :M1–R + M2–R′ → M1–R′ + M2–R where R and R′ can be, but ... reactions as well as installing isopropyl groups. An illustrative generic reaction involves the generation of the Grignard reagent derived from bromo-3,5-bis(trifluoromethyl)benzene: :(CH3)2HCMgCl + (CF3)2C6H3Br → (CH3)2HCCl + (CF3)2C6H3MgBr Isopropylmagnesium chloride is also used to prepare other isopropyl compounds, such as chlorodiisopropylphosphine:{{cite jour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Example Turbo Hauser Rktn Trans
Example may refer to: * '' exempli gratia'' (e.g.), usually read out in English as "for example" * .example, reserved as a domain name that may not be installed as a top-level domain of the Internet ** example.com, example.net, example.org, example.edu, second-level domain names reserved for use in documentation as examples * HMS ''Example'' (P165), an Archer-class patrol and training vessel of the Royal Navy Arts * ''The Example'', a 1634 play by James Shirley * ''The Example'' (comics), a 2009 graphic novel by Tom Taylor and Colin Wilson * Example (musician), the British dance musician Elliot John Gleave (born 1982) * ''Example'' (album), a 1995 album by American rock band For Squirrels See also * * Exemplar (other), a prototype or model which others can use to understand a topic better * Exemplum, medieval collections of short stories to be told in sermons * Eixample The Eixample (; ) is a district of Barcelona between the old city (Ciutat Vella) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organolithium
In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom to the substrates in synthetic steps, through nucleophilic addition or simple deprotonation. Organolithium reagents are used in industry as an initiator for anionic polymerization, which leads to the production of various elastomers. They have also been applied in asymmetric synthesis in the pharmaceutical industry. Due to the large difference in electronegativity between the carbon atom and the lithium atom, the C−Li bond is highly ionic. Owing to the polar nature of the C−Li bond, organolithium reagents are good nucleophiles and strong bases. For laboratory organic synthesis, many organolithium reagents are commercially available in solution form. These reagents are highly reactive, and are sometimes pyrophoric. History and de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Example Turbo Hauser Rktn 4
Example may refer to: * '' exempli gratia'' (e.g.), usually read out in English as "for example" * .example, reserved as a domain name that may not be installed as a top-level domain of the Internet ** example.com, example.net, example.org, example.edu, second-level domain names reserved for use in documentation as examples * HMS ''Example'' (P165), an Archer-class patrol and training vessel of the Royal Navy Arts * ''The Example'', a 1634 play by James Shirley * ''The Example'' (comics), a 2009 graphic novel by Tom Taylor and Colin Wilson * Example (musician), the British dance musician Elliot John Gleave (born 1982) * ''Example'' (album), a 1995 album by American rock band For Squirrels See also * * Exemplar (other), a prototype or model which others can use to understand a topic better * Exemplum, medieval collections of short stories to be told in sermons * Eixample The Eixample (; ) is a district of Barcelona between the old city (Ciutat Vella) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organolithium Reagent
In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom to the substrates in synthetic steps, through nucleophilic addition or simple deprotonation. Organolithium reagents are used in industry as an initiator for anionic polymerization, which leads to the production of various elastomers. They have also been applied in asymmetric synthesis in the pharmaceutical industry. Due to the large difference in electronegativity between the carbon atom and the lithium atom, the C−Li bond is highly ionic. Owing to the polar nature of the C−Li bond, organolithium reagents are good nucleophiles and strong bases. For laboratory organic synthesis, many organolithium reagents are commercially available in solution form. These reagents are highly reactive, and are sometimes pyrophoric. History and d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deprotonation
Deprotonation (or dehydronation) is the removal (transfer) of a proton (or hydron, or hydrogen cation), (H+) from a Brønsted–Lowry acid in an acid–base reaction.Henry Jakubowski, Biochemistry Online Chapter 2A3, https://employees.csbsju.edu/hjakubowski/classes/ch331/protstructure/PS_2A3_AA_Charges.html, accessed 12/2/2020 The species formed is the conjugate base of that acid. The complementary process, when a proton is added (transferred) to a Brønsted–Lowry base, is protonation (or hydronation). The species formed is the conjugate acid of that base. A species that can either accept or donate a proton is referred to as amphiprotic. An example is the H2O (water) molecule, which can gain a proton to form the hydronium ion, H3O+, or lose a proton, leaving the hydroxide ion, OH−. The relative ability of a molecule to give up a proton is measured by its p''K''a value. A low p''K''a value indicates that the compound is acidic and will easily give up its proton to a bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TMP Turbo Hauser Base
TMP can refer to any of the following: Chemistry * 2,2,6,6-Tetramethylpiperidine, an organic chemistry reagent * Thymidine monophosphate, a nucleotide * Trimethoprim, an antibiotic * Trimethyl phosphate, a solvent * Trimethylolpropane, a precursor to polymers Information and communications technology * Tab Mix Plus, a Mozilla Firefox extension * Template metaprogramming * .tmp, a temporary folder in Unix or Linux systems Media * Te Māngai Pāho, the Māori Broadcast Funding Agency * Tickle Me Pink, a band from Fort Collins, Colorado * Tiny Moving Parts, a Minnesota-based emo band * Tsukuyomi -Moon Phase-, an anime series * An abbreviation for '' Star Trek: The Motion Picture'' Business * TMP Worldwide Advertising and Communications * Todd McFarlane Productions * Trans Mountain pipeline Transport * Toyota Motor Philippines Devices * Steyr TMP, a machine pistol made by Steyr Mannlicher * Turbomolecular pump, a high vacuum pump Other * East Timor, ISO 3166-1 3-letter country co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
