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Dialkylbiaryl Phosphine Ligands
Dialkylbiaryl phosphine ligands are phosphine ligands that are used in homogeneous catalysis. They have proved useful in Buchwald-Hartwig amination and etherification reactions as well as Negishi cross-coupling, Suzuki-Miyaura cross-coupling, and related reactions. In addition to these Pd-based processes, their use has also been extended to transformations catalyzed by nickel, gold, silver, copper, rhodium, and ruthenium, among other transition metals. General features Dialkylbiaryl phosphine ligands are air-stable solids. Many are available commercially. They often can be synthesized in from inexpensive starting materials. One pot protocols have been conducted on >10 kg scales. Their enhanced catalytic activity over other ligands in palladium-catalyzed coupling reactions have been attributed to their electron-richness, steric bulk, and some special structural features. In particular, cyclohexyl, ''t''-butyl, and adamantyl groups on the phosphorus are used for this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transition Metal Phosphine Complex
A metal-phosphine complex is a In coordination complex containing one or more phosphine ligands. Almost always, the phosphine is an organophosphine of the type R3P (R = alkyl, aryl). Metal phosphine complexes are useful in homogeneous catalysis. Prominent examples of metal phosphine complexes include Wilkinson's catalyst (Rh(PPh3)3Cl), Grubbs' catalyst, and tetrakis(triphenylphosphine)palladium(0). Preparation Many metal phosphine complexes are prepared by reactions of metal halides with preformed phosphines. For example, treatment of a suspension of palladium chloride in ethanol with triphenylphosphine yields monomeric bis(triphenylphosphine)palladium(II) chloride units. : dCl2sub>n + 2PPh3 → PdCl2(PPh3)2 The first reported phosphine complexes were ''cis''- and ''trans''-PtCl2(PEt3)2 reported by Cahours and Gal in 1870. Often the phosphine serves both as a ligand and as a reductant. This property is illustrated by the synthesis of many platinum-metal complexes of trip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesylate
In organosulfur chemistry, a mesylate is any salt or ester of methanesulfonic acid (). In salts, the mesylate is present as the anion. When modifying the international nonproprietary name of a pharmaceutical substance containing the group or anion, the spelling used is sometimes mesilate (as in ''imatinib mesilate'', the mesylate salt of imatinib). Mesylate esters are a group of organic compounds that share a common functional group with the general structure , abbreviated , where R is an organic substituent. Mesylate is considered a leaving group in nucleophilic substitution reactions. Preparation Mesylates are generally prepared by treating an alcohol and methanesulfonyl chloride in the presence of a base, such as triethylamine. Mesyl Related to mesylate is the mesyl (Ms) or methanesulfonyl (CH3SO2) functional group. Methanesulfonyl chloride is often referred to as mesyl chloride. Whereas mesylates are often hydrolytically labile, mesyl groups, when attached to nit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organozincs
Organozinc compounds in organic chemistry contain carbon (C) to zinc (Zn) chemical bonds. Organozinc chemistry is the science of organozinc compounds describing their physical properties, synthesis and reactions.The Chemistry of Organozinc Compounds' (Patai Series, (Eds. Z. Rappoport and I. Marek), John Wiley & Sons: Chichester, UK, 2006, .''Organozinc reagents – A Practical Approach'', (Eds. P. Knochel and P. Jones), Oxford Medical Publications, Oxford, 1999, . Organozinc compounds were among the first organometallic compounds made. They are less reactive than many other analogous organometallic reagents, such as Grignard and organolithium reagents. In 1848 Edward Frankland prepared the first organozinc compound, diethylzinc, by heating ethyl iodide in the presence of zinc metal.E. Frankland, Liebigs Ann. Chem.,1849, 71, 171 This reaction produced a volatile colorless liquid that spontaneous combusted upon contact with air. Due to their pyrophoric nature, organozinc compounds a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthesis Of Geigerin Through Suzuki-Miyaura Coupling
Synthesis or synthesize may refer to: Science Chemistry and biochemistry *Chemical synthesis, the execution of chemical reactions to form a more complex molecule from chemical precursors **Organic synthesis, the chemical synthesis of organic compounds ***Total synthesis, the complete organic synthesis of complex organic compounds, usually without the aid of biological processes ***Convergent synthesis or linear synthesis, a strategy to improve the efficiency of multi-step chemical syntheses **Dehydration synthesis, a chemical synthesis resulting in the loss of a water molecule * Biosynthesis, the creation of an organic compound in a living organism, usually aided by enzymes **Photosynthesis, a biochemical reaction using a carbon molecule to produce an organic molecule, using sunlight as a catalyst **Chemosynthesis, the synthesis of biological compounds into organic waste, using methane or an oxidized molecule as a catalyst **Amino acid synthesis, the synthesis of an amino aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPhos
SPhos is a phosphine ligand derived from biphenyl. Its palladium complexes exhibit high activity for Suzuki coupling reactions involving aryl chlorides, which are unreactive with palladium complexes of most other phosphine ligands. The ligand has convenient handling characteristics since it is air-stable.{{cite journal , author1=Altman, R.A. , author2=Buchwald, S.L. , title = Pd-Catalyzed Suzuki-Miyaura Reactions of Aryl Halides Using Bulky Biarylmonophosphine Ligands , year = 2007 , journal = Nature Protocols , volume = 2 , issue = 12, pages = 3115–3121 , doi = 10.1038/nprot.2007.411 , pmid = 18079711 See also * XPhos XPhos is a phosphine ligand derived from biphenyl. Its palladium complexes exhibit high activity for Buchwald-Hartwig amination reactions involving aryl chlorides and aryl tosylates. Both palladium and copper complexes of the compound exhibit h ... * CPhos * Suzuki reaction References Tertiary phosphines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonogashira Coupling
The Sonogashira reaction is a cross-coupling reaction used in organic synthesis to form carbon–carbon bonds. It employs a palladium catalyst as well as copper co-catalyst to form a carbon–carbon bond between a terminal alkyne and an aryl or vinyl halide. :* : aryl or vinyl :* : arbitrary :* X: I, Br, Cl or OTf The Sonogashira cross-coupling reaction has been employed in a wide variety of areas, due to its usefulness in the formation of carbon–carbon bonds. The reaction can be carried out under mild conditions, such as at room temperature, in aqueous media, and with a mild base, which has allowed for the use of the Sonogashira cross-coupling reaction in the synthesis of complex molecules. Its applications include pharmaceuticals, natural products, organic materials, and nanomaterials. Specific examples include its use in the synthesis of tazarotene, which is a treatment for psoriasis and acne, and in the preparation of SIB-1508Y, also known as Altinicline, a nicotinic recep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XPhos
XPhos is a phosphine ligand derived from biphenyl. Its palladium complexes exhibit high activity for Buchwald-Hartwig amination reactions involving aryl chlorides and aryl tosylates. Both palladium and copper complexes of the compound exhibit high activity for the coupling of aryl halides and aryl tosylates with various amides. It is also an efficient ligand for several commonly used C–C bond-forming cross-coupling reactions, including the Negishi, Suzuki, and the copper-free Sonogashira coupling reactions. It is especially efficient and general when employed as a ( 2-aminobiphenyl)-cyclometalated palladium mesylate precatalyst complex (Buchwald's third generation precatalyst system), XPhos-G3-Pd, which is commercially available and stable to bench storage. The ligand itself also has convenient handling characteristics as a crystalline, air-stable solid.{{cite journal , author1=Altman, R.A. , author2=Fors, B.P. , author3=Buchwald, S.L. , title = Pd-Catalyzed Amination Reacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amgen Kilogram-Scale Synthesis Of P38 MAP Kinase Inhibitor Candidate
Amgen Inc. (formerly Applied Molecular Genetics Inc.) is an American multinational biopharmaceutical company headquartered in Thousand Oaks, California. One of the world's largest independent biotechnology companies, Amgen was established in Thousand Oaks, California, in 1980.Baker, Pam (2002). ''Thousand Oaks Westlake Village: A Contemporary Portrait''. Community Communications, Inc. Page 37. . Amgen's Thousand Oaks staff in 2017 numbered 5,125 (7.5% of total city employment) and included hundreds of scientists, making Amgen the largest employer in Ventura County. Focused on molecular biology and biochemistry, its goal is to provide a healthcare business based on recombinant DNA technology. In 2018, the company's largest selling product lines were Neulasta, an immunostimulator used to prevent infections in patients undergoing cancer chemotherapy and Enbrel, a tumor necrosis factor blocker used in the treatment of rheumatoid arthritis and other autoimmune diseases. Other produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suzuki Cross Coupling
is a Japanese multinational corporation headquartered in Minami-ku, Hamamatsu, Japan. Suzuki manufactures automobiles, motorcycles, all-terrain vehicles (ATVs), outboard marine engines, wheelchairs and a variety of other small internal combustion engines. In 2016, Suzuki was the eleventh biggest automaker by production worldwide. Suzuki has over 45,000 employees and has 35 production facilities in 23 countries, and 133 distributors in 192 countries. The worldwide sales volume of automobiles is the world's tenth largest, while domestic sales volume is the third largest in the country. Suzuki's domestic motorcycle sales volume is the third largest in Japan. History In 1909, Michio Suzuki (1887–1982) founded the Suzuki Loom Works in the small seacoast village of Hamamatsu, Japan. Business boomed as Suzuki built weaving looms for Japan's giant silk industry. In 1929, Michio Suzuki invented a new type of weaving machine, which was exported overseas. The company's first 30 y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
