Perfluoroalkyl derivatives of nitrogen. Part LI [1]. Reaction of the N-halogenobistrifluoromethylamines (CF3)2NX (X=Cl,Br) with norbornadiene

Reaction of the amines (CF₃)₂NX (X=Cl,Br) with norbornadiene either in solvent (CH₂Cl₂) at ?78 °C in the dark or in the vapour phase at 20 °C in daylight gives a mixture of 3-halogeno-5-($\text{NN}$-bistrifluoromethylamino)nortricyclene ($\text{exo}$, $\text{endo}$-and $\text{exo}$, $\text{exo}$-isomers) and $\text{exo}$-5-($\text{NN}$-bistrifluoromethylamino)- $\text{anti}$-7-halogenonorbornene in quantitative yield formed $\text{via}$ halonium ion addition to the diene. The reaction of the amine (CF₃)₂NBr in solvent Me₂O or Et₂O at ?78 °C in the dark gives the same products in low yield, together with 3-bromo-5-alkoxynortricyclene ($\text{exo}$, $\text{endo}$- and $\text{exo}$, $\text{exo}$-isomers) and the amine (CF₃)₂NR (R=Me, Et) in high yield.     

Reaktionen an komplexgebundenen Liganden. XXXII.: Synthese und eigenschaften von heteronuklearen mangan-chrom-komplexen mit distickstoff- diazen- und hydrazin-brükenliganden

Synthesis and properties of C₅H₅(CO)₂Mn-N₂H₄-Cr(CC)₅$\text{(1)}$, C₅H₅(CO)₂Mn-N₂H₂-Cr(CO)₅$\text{(2)}$ and C₅H₅(CO)₂Mn-N₂-Cr(CO)₅$\text{(3)}$ are reported. $\text{(1)}$, $\text{(2)}$ and $\text{(3)}$ constitute the first series of heteronuclear complexes in which N₂, N₂H₂ and N₂H₄ are bound to identical metal centers. $\text{(1)}$ and $\text{(3)}$ are obtained by reacting C₅H₅Mn(CO)₂N₂H₄ respectively with Cr(CO)₅THF, $\text{(2)}$ by oxidation of $\text{(1)}$. $\text{(2)}$ disproportionates by addition of base yielding $\text{(3)}$ and H₂. The IR Spectrum of $\text{(2)}$ allows the assignment of five normal vibrations of the diazene ligand; in the IR spectrum of the deuterated analogue all six normal vibrations can be assigned. The ¹H-NMR spectrum of $\text{(2)}$ yields the coupling constant of protons on NN double bonds for the first time; the value of ³J_HH  23,5 Hz points to a trans structure of $\text{(2)}$.     

An unusual chlorination of 1-phenyl-4-(2,6-dichlorophenyl)-1,3-butadiene

The diene $\text{1a}$ reacted with CHCl₃/aq. NaOH/PTC in CH₂ Cl₂ unexpectedly to give a mixture of the chlorination products $\text{2}$ and $\text{3a}$. Usual chlorination with Cl₂ yielded similarly $\text{2}$, $\text{3a}$, and $\text{3b}$ dependent on the amount of Cl₂. The formation of $\text{2}$ as well as the reaction of $\text{7}$ to give $\text{9}$ (besides $\text{8}$) shows an unusual Cl-Cl-interaction.     

Perhalogenmethylmercapto-heterocyclen, (VII) [1] konkurrenzreaktionen elektronenarmer,substituierter aromaten um die halogenmethylmercapto- BZW. Chlorgruppe von Cl3-nFnCSCl in starken saeuren

Electron-deficient aromatics, such as 2,5-bis(trifluoromethylmercapto)thiophene ($\text{1a}$) or (trifluoromethylmercapto)benzene ($\text{8a}$), react with F₃CSCl in the presence of F₃CSO₃ as a catalyst to give mainly 3-chloro-2,5-bis(trifluoromethylmercapto)thiophen ($\text{3a}$) and 1-chloro-4- or 2-(trifluoromethylmercapto)benzene ($\text{10}$, respectively. This reaction competes with the one expected to result in 2,3,5-tris(trifluoromethylmercapto)thiophene ($\text{2a}$) and 1,4- and 1,2-bis(trifluoromethylmercapto)benzene ($\text{9}$,$\text{9′}$), respectively. Further reactions of deactivated aromatics with Cl_3-nF_nCSCl show that the chlorine substitution is in general catalysed by strong acids. Reaction mechanisms are proposed for both Substitutions. The Cl_3-nF_nCS group in aromatics exerts a -M-effect in the case of an attack of a positive ion, e.g. H^⊕, the well-known +M-effect in the case of reactions with positively polarized molecules, e.g. CF₃S^β+Cl^β-.     

From penicillin to penem and carbapenem. VI1) : Synthesis of dethiathienamycin

A new C₃-unit substitution reaction at C-4 position of 4- acetoxyazetidinone derivative ($\text{1}$ and $\text{5}$) by tetraallyltin ($\text{2}$) in the presence of 1/10 eq. of BF₃-ether in methylene chloride is described. From 4-allylazetidinone derivative ($\text{3}$) via ylid intermediate ($\text{14}$) dethiathienamycin ($\text{16}$) was synthesized.     

Reductive coupling of α,β-enones I: Reduction of methyl-vinyl ketone and mesityl oxide.

Reductive coupling of methyl-vinyl ketone with TiCl₄-Mg gives pinacol $\text{1}$ (25%). According to the reducing agents, mesityl oxide yields 2,4,5,7-tetramethyl-octa-2,4,6-triene $\text{3}$ (with 4TiCl₃-LialH₄), triene $\text{3}$ or 2,4,5,7-tetramethyl-octa-2,6-dien-4,5-diol $\text{5}$ (with TiCl₄-Mg), pinacol $\text{5}$ (with VCl₃-Mg), and 2-acetyl-1,3,3,4,4-pentamethyl-cyclopentane $\text{7}$ (with CrCl₃-Mg or FeCl₃-Mg or ZrCl₄ or ZrCl₄-Mg) as major products.     

Methylated multibridged [2n]cyclophanes. All alternate synthesis of [26](1,2,3,4,5,6) cyclophane (superphane)

A sequence of formylation followed by a carbene insertion reaction has led to the stepwise introduction of additional ethano bridges into 4,5,7,8- tetramethyl [2₂](1,4)cyclophane ($\text{1}$), providing syntheses of 5,7,8-trimethyl- [2₃](l,2,4)cyclophane ($\text{6}$), a mixture of 5,8-dimethyl[2₄(1,2,4,5)cyclophane ($\text{10}$) and 5,7-dimethyl[2₄(1,2,3,5)cyclophane ($\text{11}$, and-4-methyl[2₅](1,2,3,4,5)-cyclophane ($\text{14}$). This route to $\text{14}$ completes a formal eight-step synthesis of [2₆](1,2,3,4,5,6)cyclophane ($\text{15}$, superphane) with an overall yield of 17%. A Birch reduction of $\text{6}$ readily gave 12,15-dihydro-5,7,8-trimethyl[2₃](1,2,4)-cyclophane ($\text{7}$) in 85% yield.     

Preparation and synthetic utility of fluorinated phosphonium salts,bisphosphonium salts and phosphoranium salts

The synthesis and mechanism of formation of phosphonium salts of the type [R₃$\text{P}\text{+}$CFXY]Z^? (where X = F, Cl, Br; Y = Br, Cl; Z = Br, Cl), $\text{bis}$-phosphonium salts of the type [R₃$\text{P}\text{+}$CF₂$\text{P}\text{+}$R₃]2Br^?, and phosphoranium salts of the type [R₃$\text{P}\text{+}$$\text{C}\text{?}$F$\text{P}\text{+}$R₃]X^? (X = Br, Cl) will be presented. The applicability of these substrates in the generation of useful nucleophilic or electrophilic synthetic intermediates will be discussed.     

Reactions of triphenylarsine oxide with aqueous hydrogen fluoride: Crystal structure of bis(triphenylarsine oxide)hydrogen(I) tetrafluoroborate

Fluorination of triphenylarsine oxide by aqueous hydrogen fluoride (1–40%) in the absence of glass readily gives triphenylarsine difluoride. When the reaction with dilute (1%) aqueous hydrogen fluoride is carried out in borosilicate glass apparatus, the glass participates in the reaction resulting in the formation of the crystalline 2:1 adduct 2Ph₃AsO·HBF₄. Crystals of this compound are monoclinic, $\text{P}$2₁/$\text{c}$, $\text{a}$ = 12.926(4), $\text{b}$ = 17.819(6), $\text{c}$ = 14.994(4) Å, β = 98.97(3)°, Z = 4. The structure contains cations [(Ph₃AsO)₂H]⁺ in which $\text{O}\text{?}$O is 2.44(2)Å, and anions BF₄^?.     

A practical synthesis of fluoromethyltriphenylphosphonium salts

A practical synthesis of [Ph₃$\text{P}\text{+}$CH₂F]BF₄^? is reported $\text{via}$ two routes, $\text{via}$ fluorination of [Ph₃$\text{P}\text{+}$CH₂OH]BF₄^? with DAST or $\text{via}$ hydrolysis of the phosphoranium salt, [Ph₃$\text{P}\text{+}$$\text{C}$F$\text{P}\text{+}$Ph₃]Br^?.     

Trimethymetall-urotropinaddukte des aluminiums,galliums, indiums und thalliums

Reactions of urotropine (C₆H₁₂N₄) with trimethylmetal derivatives of Al, Ga, In und Tl in various ($\text{1}\text{1}$$\text{1}\text{4}$) molar ratios lead to stable and monomeric $\text{1}\text{1}$, $\text{1}\text{2}$ or $\text{1}\text{3}$ adducts in good yields, but no $\text{1}\text{4}$ addition product could be isolated. The vibrational spectra (IR and Raman) of all compounds are recorded and partly assigned. Some characteristic frequencies of the C₆N₄-skeletons clearly show the symmetry changes in the series of the $\text{1}\text{1}$ → $\text{1}\text{2}$ → $\text{1}\text{3}$ adducts (C_3ν → C_2ν → C_3ν). The X-ray structure determinations of C₆H₁₂N₄·.GaMe₃ (MeCH₃) and C₆H₁₂N₄·.2GaMe₃, are in good agreement with the vibrational spectra. Both compounds crystallize in monoclinic space groups (P2₁ and C2/c). The GaN distances are around 214 pm, and the values for the C₆N₄-skeletons are not significantly different from those for free urotropine.     

Metal—metal bonding in dinuclear complexes of platinum(I). The crystal and molecular structure of carbonyl(chloro)-bis-μ-[bis(diphenylphosphino)methane]diplatinum hexafluorophosphate

The structure of [Pt₂Cl(CO) (μ-Ph₂PCH₂PPh₂)₂] [PF₆] was determined by $\text{X}$-ray methods and refined to $\text{R}$ = 0.082, using diffractometric intensities of 5646 independent reflections. The crystals are monoclinic, space group $\text{P}$2₁/$\text{n}$, $\text{a}$ = 12.919(3), $\text{b}$ = 15.576(6), $\text{c}$ = 25.151(5)Å, β = 94.82(3)°, $\text{Z}$ = 4. They are built of octahedral hexafluorophosphate anions and dinuclear platinum(I) cations. The latter contain PtCl and PtCO fragments linked to one another by a PtPt σ-bond and by two bridging bis(diphenylphosphino)methane ligands. The platinum atoms are in square planar environments and the dihedral angle between the two coordination planes is 40.1°. Selected bond lengths are: PtPt 2.620(1), PtCl 2.384(5), PtC 1.89(3) and PtP 2.291(5) – 2.308(5)Å.     

Synthesis and chemistry of HC(SO2F)3 and cis- and trans(HO)2TeF4

HC(SO₂F)₃ has been prepared and characterized. It turned out to be a strong acid, comparable to mineral acids. In aqueous solution the salts of the type Cs⁺C(SO₂F)₃^? are formed. The anion, as found by crystal structure analysis contains planar CS₃ configuration.Quite in contrast to these findings HC(OSO₂F)₃ is not even soluble in water.Derivatives of HC(SO₂F)₃ have been prepared so far CH₃C(SO₂F)₃ FC(SO₂F)₃ ClC(SO₂F)₃ BrC(SO₂F)₃ JC(SO₂F)₃The heavier halogen derivatives ( Cl, Br, J ) are oxidizing agents (‘positive halogen’).A mixture of $\text{cis-}$ and $\text{trans-}$ (HO)₂TeF₄ is obtained if HOTeF₅ and Te(OH)₆ are melted together. The mixture of the isomeres have been transfered into the corresponding silylesters $\text{cis}$- and $\text{trans-}$ (R₃SiO)₂TeF₄, which could be separated by fractional crystallisation and distillation.Without conformational change the pure silylesters have been reacted back to pure $\text{cis}$- (HO)₂TeF₄ and $\text{trans}$- (HO)₂TeF₄ by means of anhydrous HF. Both $\text{cis-}$ and $\text{trans}$ (HO)₂TeF₄ have been reacted with ClF to give $\text{cis}$- and $\text{trans}$- (ClO)₂TeF₄, yellow liquids. The latter react with elemental bromine to the rather unstable $\text{cis-}$ and $\text{trans-}$ (BrO)TeF₄, red liquids.Starting with $\text{cis}$-(HO)₂TeF₄ and XeF₂ a polimer Xenon compound of the formula

All materials have been characterized by melting point and vapour pressure, 19 F - nmv spectroscopy, vibrational spectroscopy, and elemental analysis.     

Synthesis and crystal structure of 1,1,1,5,5,5-hexafluoro-2-aminopentan-4-one (HFAP)

The vapour phase reaction of ammonia and hexafluoroacetylacetone leads to the formation of the new β-keto-amine C₅H₃F₆NO. Crystals of the compound are monoclinic, space group $\text{P}$2₁/$\text{n}$, $\text{a}$ = 10.01(2), $\text{b}$ = 19.33(3), $\text{c}$ = 8.40(1) Å, β = 82.27(6)°; final R = 0.044.     

Halogen cleavage reactions of cis-(threo-PhCHDCHD)Mn(CO)4PEt3

Halogen cleavage reactions of $\text{cis}$-($\text{threo}$-PhCHDCHD)Mn(CO)₄, PEt₃ ($\text{3}$) are studied in detail and are found to proceed either predominantly with retention or inversion, or non-stereospecifically, depending on reaction conditions. Reaction mechanisms involving S_E2 (inversion), S_E2 (retention) and S_E (oxidative) processes are proposed, demonstrating that halogen cleavage reactions of $\text{3}$ straddle the mechanistic borderline between electrophilic substitution and oxidation processes of transition metal alkyl compounds.     

Adenosine cyclic 3′,5′-(RP)- and (SP)-phosphoramidates,the first representatives of nucleoside cyclic 3′,5′-phosphoramidates derived from ammonia

Adenosine cyclic 3′,5′-phosphoramidate $\text{2}$ was synthesized by reacting adenosine cyclic 3′,5′-phosphate $\text{1}$ with POCl₃, in trimethyl phosphate for 1 h at O°C, followed by in situ treatment of the reaction mixture with a suspension of (NH₄)₂CO₃ in anhydrous DMF or pyridine or DMF/pyridine mixture for 30 min at 25° C. Diastereoisomers ($\text{R}$_P)-$\text{2}$ and ($\text{S}$_P)-$\text{2}$ the relative quantities of which depended on the solvent of (NH₄)₂CO₃ treatment, were separated by reversed phase partition chromatography. Hydrolysis of (R_P)-$\text{2}$ and (S_P)-$\text{2}$ proceeded with predominant (90% in 0.1 N HCl, 100% in 0.1 N NaOH) -P-O-C bond breaking.     

Cyanosugars III : The reaction of trimethylsilyl cyanide with keto,epoxy and acetal derivatives of carbohydrates

Reaction of methyl 2-acetamido-4,6-$\text{O}$-benzylidene-2-deoxy-α-$\text{D}$-$\text{ribo}$-hexopyranosid-3-ulose with Me₃SiCN afforded methyl 2-acetamido-4,6-$\text{O}$-benzylidene-3-$\text{C}$-cyano-2-deoxy-3-$\text{O}$-trimethylsilyl-α-$\text{D}$-$\text{allo}$- Reaction of ethyl 4,6-di-$\text{O}$-acetyl-2,3-anhydro-α-$\text{D}$-mannopyranoside with Me₃SiCN gave the corresponding ethyl 4,6-di-$\text{O}$-acetyl-2-$\text{C}$-cyano-2-deoxy-α-$\text{D}$-glucopyranoside. Reaction of methyl 4,6-$\text{O}$-benzylidene-2,3-anhydro-α-$\text{D}$-allopyranoside or methyl 4,6-$\text{O}$-benzylidene-2,3-di-$\text{O}$-tosyl-α-$\text{D}$-glucopyranoside with Me₃SiCN at - 75° or - 50° gave the corresponding methyl 6-$\text{O}$-[(R)-cyano phenyl methyl]-α-$\text{D}$-glyco-pyranosides with high or total regio and stereoselectivity.     

Reactions of o-tolyl isocyanide with isocyanate and isothiocyanate syntheses of n-substituted indole-3-carboxamides and indole-3-thiocarboxamides

o-Lithomethylphenyl isocyanide is reacted at ?78° with isocyanates and isothiocyanates to produce o-isocyanophenyl-acetamides $\text{(2a)}$ and -acetothioamides $\text{(2b)}$. Isocyanides $\text{(2a)}$ and $\text{(2b)}$ are cyclized to indole-3-carboxamides $\text{(3a)}$ and -3-thiocarboxamides $\text{(3b)}$ via lithiathion, respectively. Isocyanides $\text{2a}$ are also cyclized by Cu₂O catalyst to produce 4,5-dihydro-1,3-benzodiazepin-4-ones $\text{(4a)}$ with $\text{(3a)}$.     

Fluorescence of ammonia-d3 from its first excited singlet state

Structured emission spectra have been observed from ND₃ excited at 2139 Å and 2144 Å. The emission is short-lived (τ_{$\text{1}\text{2}$} < 10^?10 s) and has been assigned to the ND₃($\text{A}$) → ND₃($\text{X}$) fluorescence transition.     

Reaction of 5,5-diphenyl-2-thiohydantoin with 1,2-dibromoethane.crystal and molecular structures of 2,3-dihydro-6,6-diphenylimi-dazo-[2,1-b]-thiazol-5(6h)-one and 2,3-dihydro-5,5-diphenylimi-dazo-[2,-1-b]-thiazol-6(5h)-one and their reactivity

The crystal and molecular structures of the title isomeric compounds $\text{1}$ and $\text{2}$, obtained by intramolecular N,S--dialkylation of 5,5-diphenyl-2-thiohydantoin with 1,2-dibro-moethane, have been determined from X-ray diffractometer data. 2,3-Dihydro-6,6-diphenylimidazo-[2,1-b]-thiazol-5(6H)-one $\text{1}$ crystallizes in space group P2₁2₁2₁ with a=11.376(3), b=12,255(5), c=8.434(3) Å and Z=4. Crystals of $\text{2}$, containing one molecule of benzene, are monoclinic,space group P2₁/c with a=11.539(6), b=10.242(3), c=16.353(5) Å, β=95.45(5)° and Z=4. In both cases a planar geometry of the two fused five-membered heterocyclic rings was found. The selected bond lengths in $\text{1}$ and $\text{2}$, as well as those analogous imidazothiazinones $\text{3}$ and $\text{4}$, were used to calculate E_HOSE (Harmonic Oscillation Stabilization Energy). The problem of stability and chemical reactivity of compounds $\text{1}$ to $\text{4}$ is also discussed.