Replacement of Trimethylamine in Trimethylamine‐trispentafluoroethyl‐borane. Structures of [(C2F5)3BNMe3], [NMe4][(C2F5)3BOH], and K[(C2F5)3BCH2(CO)C6H5]

Trimethylamine‐tris(pentafluoroethyl)borane [(C₂F₅)₃BNMe₃] ( 1 ) reacts at 190 °C with water under displacement of the trimethylamine ligand to yield the hydroxy‐tris(pentafluoroethyl)borate [(C₂F₅)₃BOH]^? ( 2 ). In tributylamine 1 reacts with alkynes HC≡CR to form novel ethynyl‐tris(pentafluoroethyl)borate anions [(C₂F₅)₃BC≡CR]^? – R = C₆H₅ ( 3 ), C₆H₄CH₃ ( 4 ), Si(CH(CH₃)₂)₃ ( 5 ) – in moderate yields. Compound 3 adds water across the triple bond to form the novel anion [(C₂F₅)₃BCH₂(CO)C₆H₅]^? ( 6 ). The structures of [(C₂F₅)₃BNMe₃], [NMe₄][(C₂F₅)₃BOH] and K[(C₂F₅)₃BCH₂(CO)C₆H₅] have been determined by x‐ray crystallography.     

Synthesen und Eigenschaften von Pentafluorethylkupfer(I)‐ und ‐(III)‐Verbindungen: Cu(C2F5) · D, [Cu(C2F5)2]– und (C2F5)2CuSC(S)N(C2H5)2

Syntheses and Properties of Pentafluoroethylcopper(I) and ‐copper(III) Compounds: CuC₂F₅ · D, [Cu(C₂F₅)₂]^–, and (C₂F₅)₂CuSC(S)N(C₂H₅)₂ The reactions of Cd(C₂F₅)₂ · D and Zn(C₂F₅)₂ · D (D = 2 CH₃CN, 2 DMF), respectively, with copper(I) halides in the presence of halides quantitatively yield the CuC₂F₅ compounds CuC₂F₅ · D and [Cu(C₂F₅)₂]^–. The CuC₂F₅ complexes are identified by NMR spectroscopy, while [Cu(C₂F₅)₂]^– is isolated as PNP salt (PNP = (C₆H₅)₃PNP(C₆H₅)₃⁺). Both compounds are excellent C₂F₅ group transfer reagents, even at low temperature. Oxidation of [Cu(C₂F₅)₂]^– with [(C₂H₅)₂NC(S)S]₂ yields the crystalline Cu(III) compound (C₂F₅)₂CuSC(S)N(C₂H₅)₂ (monoclinic, C2/c).     

Fluoroborates by Cleavage of Trimethylamine‐bis(trifluoromethyl)boranes with NEt3 × 3 HF. Structures of C6F5(CF3)2B · NMe3, K[C6H5CH2(CF3)2BF], and K[C6H5(CF3)2BF]

Trimethylamine‐bis(trifluoromethyl)boranes R(CF₃)₂B · NMe₃ (R = cis/trans‐CF₃CF=CF ( 1/2 ), HC≡C ( 3 ), H₂C=CH ( 4 ), C₂H₅ ( 5 ), C₆H₅CH₂ ( 6 ), C₆F₅ ( 7 ), C₆H₅ ( 8 )) react with NEt₃ × 3 HF depending on the nature of R at 155–200 °C under replacement of the trimethylamine ligand to form the corresponding fluoro‐bis(trifluoromethyl)borates [R(CF₃)₂BF]^– ( 1 a/2 a – 8 a ). The structures of 7 , K[C₆H₅CH₂(CF₃)₂BF] ( K‐6 a ), and K[C₆H₅(CF₃)₂BF] ( K‐8 a ) have been investigated by single‐crystal X‐ray diffraction. In 7 the CF₃ groups make short repulsive contacts with NMe₃ and C₆F₅ entities – the B–CF₃ bonds being unusually long. The B–F bond lengths of K‐6 a and K‐8 a (1.446(3) and 1.452(2) Å, respectively) are long for a fluoroborate.     

[2+4] and [2+2] Cycloaddition Reactions of N‐Sulfinyl Carboxylic Acid Amides with (CF3)2BNMe2. Crystal Structure of cyclo‐(CF3)2B‐NMe2‐S(=O)‐N=C(p‐CH3C6H4)‐O

N‐sulfinylacylamides R‐C(=O)‐N=S=O react with (CF₃)₂BNMe₂ ( 1 ) to form, by [2+4] cycloaddition, six‐membered rings cyclo‐(CF₃)₂B‐NMe₂‐S(=O)‐N=C(R)‐O for R = Me ( 2 ), t‐Bu ( 3 ), C₆H₅ ( 4 ), and p‐CH₃C₆H₄ ( 5 ) while N‐sulfinylcarbamic acid esters R‐O‐C(=O)‐N=S=O react with 1 to yield mixtures of six‐membered (cyclo‐(CF₃)₂B‐NMe₂‐S(=O)‐N=C(OR)‐O) and four‐membered rings (cyclo‐(CF₃)₂B‐NMe₂‐S(=O)‐N(C=O)OR) for R = Me ( 6 and 9 ), Et ( 7 and 10 ), and C₆H₅ ( 8 and 11 ). The structure of 5 has been determined by X‐ray diffraction.     

Hypervalent Pentafluoroethylgermanium Compounds, [(C2F5)nGeX5−n]− and [(C2F5)3GeF3]2− (X=F,Cl; n=2–5)

This paper gives an account on hypervalent fluoro‐ and chloro(pentafluoroethyl)germanium compounds. The selective synthesis of the tris(pentafluoroethyl)dichlorogermanate salt [PNP][(C₂F₅)₃GeCl₂] as well as its X‐ray structural analysis is described. As a representative example for pentafluoroethylfluorogermanates, the synthesis and structure of 2,4,6‐triphenylpyryliumtris(pentafluoroethyl)difluorogermanate [C₂₃H₁₇O][(C₂F₅)₃GeF₂] is reported. Fluoride‐ion affinities for pentafluoroethylgermanes were calculated using quantum chemical methods, disclosing (C₂F₅)₃GeF as a weaker Lewis acid than (C₂F₅)₃SiF or (C₂F₅)₃PF₂. The theoretical results were confirmed by experiments and give the basis of a synthetic protocol for (C₂F₅)₃GeF. Pentakis(pentafluoroethyl)germanate [PPh₄][Ge(C₂F₅)₅] was detected as an intermediate during the synthesis of [PPh₄][(C₂F₅)₄GeF] starting from tris(pentafluoroethyl)difluorogermanate and LiC₂F₅.     

[Ph2P(O)CH2Im][F3B(μ‐OH)BF3]. Erste strukturanalytische Charakterisierung des Hexafluoro(μ‐hydroxo)diborat‐Ions [1]

[Ph₂P(O)CH₂Im][F₃B(μ‐OH)BF₃]. First Structural Characterization of the Hexafluoro(μ‐hydroxo)diborate Ion [1] The hexafluoro(μ‐hydroxo)diborate ion has been isolated as it's Ph₂P(O)CH₂Im salt [Im = 2‐(1, 3, 4, 5‐tetramethylimidazolio)] ( 2 ) through basic hydrolysis of [Ph₂P(OBF₃)CH₂Im]BF₄ ( 1 ). The crystal structure of 2 · CH₂Cl₂ reveals the presence of ion pairs linked by unsymmetrical O‐H‐O hydrogen bonds.     

BF3‐OEt2‐Mediated Rearrangement of (4‐Phenylpiperidin‐4‐Yl)‐Arylmethanols

Synthesis of several 4‐benzhydrylidenepiperidine analogs has been established starting from different (4‐phenylpiperidin‐4‐yl)‐arylmethanols via boron trifluoride etherate mediated rearrangement. The possible rearranged mechanism was proposed. Boron trifluoride etherate‐mediated rearrangement of the related derivatives was also examined. It presents a novel rearrangement reaction catalyzed by boron trifluoride etherate and broadens the scope of application.     

Darstellung von [(C2H5)2NH2]3[PS3F]F und [(C2H5)2NH2]3[PS2SeF]F und Kristallstruktur der selenhaltigen Phase

Preparation of [(C₂H₅)₂NH₂]₃[PS₃F]F and [(C₂H₅)₂NH₂]₃ [PS₂SeF]F and Crystal structure of the Phase with Selenium The title compounds were prepared by reaction of diethylammon ium-trithiophosphite with fluoride ions (as diethylammonium fluoride) and sulfur and selenium, respectively. The crystal structure of the selenium containing phase was determined. It does not represent a phosphoranate with a [PS₂SeF₂]^3? anion, but a double salt of [PS₂SeF]^2? with F^?.     

Crystallographic report: Diiodo[tris(2‐pyridyl)amine]zinc(II), [(C5H4N)3N]ZnI2

The zinc(II) atom in the molecule of [(C₅H₄N)₃N]ZnI₂ is tetrahedrally coordinated to two nitrogen atoms of the tris(2‐pyridyl)amine ligand and two iodides. The coordination moieties are connected to give a linear structure by intermolecular π–π interactions between the pyridyl rings. Copyright © 2003 John Wiley & Sons, Ltd.     

Crystallographic report: Diiodo[tris(2‐pyridyl)amine]mercury(II), [(C5H4N)3N]HgI2

In mononuclear HgI₂[(C₅H₄N)₃N], mercury is tetrahedrally coordinated by two nitrogen atoms of a tris(2‐pyridyl)amine ligand and two iodides. The coordination moieties are connected by weak intermolecular Hg(II)···I interactions to give a one‐dimensional structure. Copyright © 2003 John Wiley & Sons, Ltd.     

Crystallographic report: Bis[tris(2‐pyridyl)amine]cadmium(II)‐di‐µ‐chloro‐dichloro‐cadmium(II), [(C5H4N)3N]2CdCl2CdCl2

In the dinuclear molecule of [(C₅H₄N)₃N]₂CdCl₂CdCl₂, one cadmium is octahedrally coordinated by a Cl₂N₄ donor set and the other cadmium is tetrahedrally coordinated by four chlorine atoms. The dinuclear units are connected by π–π interactions to give a two‐dimensional network. Copyright © 2003 John Wiley & Sons, Ltd.     

5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成

以5-雄烯二醇为原料,用微生物转化的方法合成了两个重要的神经甾体5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇。所用菌种总枝毛霉为我们自己筛选,并首次应用于5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成中。