Treatment of a solution of a mixture of 1-aryl-2-arylsulfonylethanones 9 and alkylsulfonyl chlorides (1.5-2.0 equiv) in THF at 0 degree C with potassium hydroxide (8 equiv) for 10 min gave a rearrangement product, i.e., 1-aryl-2-(arylsulfonylmethanesulfonyl)ethanones 8, in excellent yields. Regiospecific methyl- and ethylation at the methylene carbon sandwiched between two sulfonyl groups of 8 could be achieved by the reactions of 7i-j with LDA (1 equiv) in THF at room temperature, respectively.
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http://dx.doi.org/10.1021/ol0482285 | DOI Listing |
Dalton Trans
December 2024
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Jiangwan Campus, Fudan University, Shanghai 200438, China.
The phosphaguanidinate rare-earth-metal bis(aminobenzyl) complexes [(PhP)C(NCHPr-2,6)]Ln(CHCH NMe-) (Ln = Y(1-Y) and Lu(1-Lu)) were synthesized by the protonolysis of (PhP)[C(NHR)(NR)] (R = 2,6-(Pr)CH) with Ln(CHCHNMe-) (Ln = Y and Lu). Interestingly, the ring-opening rearrangement product [-MeNCHCHC(NCHPr-2,6)]Lu(CHCHNMe-)[O(CH)PPh] (2) was obtained when the acid-base reaction was carried out in THF solution at 60 °C for 36 h. Additionally, the trinuclear homometallic yttrium multimethyl/methylidene complex {[(PhP)C(NCHPr-2,6)]Y(μ-Me)}(μ-Me)(μ-CH) (3) was synthesized by the treatment of 1-Y with AlMe (2 equiv.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Brest University: Universite de Bretagne Occidentale, Chemistry, FRANCE.
Whereas molybdenum dinitrogen complexes have played a major role as catalytic model systems of nitrogenase, corresponding tungsten complexes were in most cases found to be catalytically inactive. Herein, we present a modified pentadentate tetrapodal (pentaPod) phosphine ligand in which two dimethylphosphine groups of the pentaPodMe (P5Me) ligand have been replaced with phospholanes (Pln). The derived molybdenum complex [Mo(N2)P5Pln] generates 22 and the analogous tungsten complex [W(N2)P5Pln] 7 equivalents of NH3 from N2 in the presence of 180 equiv.
View Article and Find Full Text PDFChem Commun (Camb)
December 2024
Department of Chemistry, University of Pennsylvania, 231 S 34th St, Philadelphia, PA 19104, USA.
Reduction of [K{(pyrrpyr)Fe}(μ-N)] (1) with two equiv. of KC in the presence of crown-ether 18-C-6 yields the N adduct [{K(18-C-6)}(pyrrpyr)Fe(N)] (2). Complex 2 heterolytically splits the C-H bond of benzene to form [{K(18-C-6)}(pyrrpyr)Fe(CH)] (3), whereby usage of a diboron Bpin promotes hydride elimination to form the salt [K(18-C-6)HBPin] (4).
View Article and Find Full Text PDFDalton Trans
November 2024
Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
The carbene-stabilised beryllium Grignards [(CAAC)BeBrR] (R = CAACH 1a, Dur 1b; CAAC/H = 1-(2,6-dipropylphenyl)-2,2,4,4-tetramethylpyrrolidin-2-yl/idene; Dur = 2,3,5,6-tetramethylphenyl) undergo salt metathesis with various pseudohalide salt precursors. Whereas with [NaNCS] the thiocyanato Grignards [(CAAC)Be(NCS)R] (R = CAACH 2a, Dur 2b) are obtained selectively, salt metatheses with [Na(OCP)(dioxane)] and [K(OCN)] are fraught with side reactions, in particular scrambling of both neutral and anionic ligands, leading to complex product mixtures, from which the first examples of beryllium phosphaethynolate Grignards [(thf)(CAACH)Be(OCP)] (3) and [(CAAC)Be(OCP)R] (R = CAACH 4a, Dur 4b), as well as the isocyanate-bridged hexamer [(CAAC)BrBe(1,3-μ-OCN)] (7) were determined as the main products. The complexity of possible side reactions is seen in complex 5, a byproduct of the salt metathesis of 1b with [Na(OCP)(dioxane)], which hints at radical redox processes, OCP homocoupling, OCP coupling with CAAC, as well as OCP insertion into the Be-R bond.
View Article and Find Full Text PDFInorg Chem
November 2024
Department of Chemistry, McMaster University, 1280 Main St. West, Hamilton, Ontario L8S 4M1, Canada.
Boranes featuring bulky hypersilyl or supersilyl groups and/or sterically unencumbered trimethylgermyl substituents were synthesized for investigation as potential precursors for atomic layer deposition (ALD) of elemental boron. The envisaged ALD process would employ a boron trihalide coreactant, exploiting the formation of strong silicon-halogen and germanium-halogen bonds as a driving force. The alkali metal silyl and germyl compounds hypersilyl lithium, {(MeSi)Si}Li(THF) (), supersilyl sodium, (BuSi)Na(THF) (, = 2-3), and trimethylgermyl lithium, {MeGeLi(THF)} (), were used for the synthesis of the silyl- and germyl-substituted boranes in this work.
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