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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] |
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] |
CPhos
CPhos is a phosphine ligand derived from biphenyl. It is a white solid that is soluble in organic solvents. Its palladium complexes exhibit high activity for Negishi coupling reactions involving aryl bromides, chlorides and triflates. CPhos mediated reactions performed with secondary (sp3) alkylzinc halides often give excellent yields, with low conversion to the frequently encountered primary substituted by-products. Utility in Negishi Coupling A simplified scheme showing the reaction course of isopropylzinc bromide with an aryl halide is shown below. Processes leading to byproduct formation are highlighted in red. Oxidative addition (1) of the aryl halide to the palladium-ligand complex followed by transmetalation (2) gives intermediate B which can undergo reductive elimination (3) to afford the desired isopropyl arene C. However, intermediate B can also undergo β-hydride elimination (4) to afford D, which can either reductively eliminate (3’) to afford de-halogenated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphine Ligand
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 triphenylph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biphenyl
Biphenyl (also known as diphenyl, phenylbenzene, 1,1′-biphenyl, lemonene or BP) is an organic compound that forms colorless crystals. Particularly in older literature, compounds containing the functional group consisting of biphenyl less one hydrogen (the site at which it is attached) may use the prefixes xenyl or diphenylyl. It has a distinctively pleasant smell. Biphenyl is an aromatic hydrocarbon with a molecular formula (C6H5)2. It is notable as a starting material for the production of polychlorinated biphenyls (PCBs), which were once widely used as dielectric fluids and heat transfer agents. Biphenyl is also an intermediate for the production of a host of other organic compounds such as emulsifiers, optical brighteners, crop protection products, and plastics. Biphenyl is insoluble in water, but soluble in typical organic solvents. The biphenyl molecule consists of two connected phenyl rings. Properties and occurrence Biphenyl occurs naturally in coal tar, crude oil, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amide
In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent organic groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, such as in the amino acids asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid () with the hydroxyl group () replaced by an amine group (); or, equivalently, an acyl (alkanoyl) group () joined to an amine group. Common examples of amides are acetamide (), benzamide (), and dimethylformamide (). Amides are qualified as primary, secondary, and tertiary according to whether the amine subgroup has the form , , or , where R and R' are groups other than hydrogen. The core of amides is called the amide group (specifically, carboxamide group). Amides are pervasive in nature and technology. Proteins and important plastics l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature Protocols
''Nature Protocols'', published by the Nature Publishing Group, is an on-line scientific journal publishing methods in a recipe-style format. The journal was launched in June 2006 and the content includes both classical methods and cutting-edge techniques relevant to the study of biological problems. The content on this site is divided into "Nature Protocols" and the "Protocol Exchange". Initially, all "Nature Protocols" were commissioned by editors, but it is now possible for authors to upload pre-submission enquiries. All Nature Protocols are peer reviewed, fully edited and styled prior to publication. New protocols are added to the site on a weekly basis. Published protocols Published protocols are sorted into the following categories: * Biochemistry * Cell and tissue culture * Cell biology and developmental biology (includes detection of apoptosis and others) * Computational biology and theoretical biology (includes bioinformatics) * Genetic analysis (includes classical g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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