bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Crystal Structure of (1, 1′‐ferrocenediyl)diphenylsilane
Authors: Stoeckli‐Evans Helen , Osborne Anthony G. , Whiteley Richard H. 
Published: December 2004

AbstractThe crystal structure of (1,1′‐ferrocenediyl)diphenylsilane has been determined from analysis of photographic X‐ray data. The crystal system is orthorhombic, a = 14.18(2), b = 12.54(2), c = 9.28(1) Å, space group Pnma with four formula units. The molecule has crystallographic m (Cs) symmetry with atoms Fe and Si lying in the mirror plane, which bisects the two phenyl groups. The planar cyclopentadienyl rings are bridged by a single silicon atom, and are tilted 19.2° with respect to one another. The Fe—C(Cp) distances vary from 2.01(1) to 2.11(1) Å. The bridging angle C(1)—Si—C(1′) is 99.1°, while the Si—C(sp2) bond lengths range from 1.86 to 1.88 Å. The exocyclic C(1)—Si bond makes an angle of 40° with respect to the plane of the cyclopentadienyl ring.
Contribution à la phytochimie du genre Gentiana, XVIII. Structure du gentiabavarutinoside, un nouveau glycoside xanthonique acylé isolé de Gentiana bavaricaL
Authors: Hostettmann Kurt , Jacot‐Guillarmod André , Chari Vedantha M. 
Published: December 2004

Phytochemistry of genus Gentiana, XVIII: Structure of gentiabavarutinoside, a new acylated xanthone glycoside from Gentiana bavarica L.In a previous work [1], we isolated from Gentiana bavarica L. an acylated xanthone glycoside (1,8‐dihydroxy‐3‐methoxy‐xanthone‐7‐O‐acetylrutinoside 1 or gentiabavarutinoside) without locating the acetyl group. By 13C‐NMR. spectroscopy, the attach position of the acetyl is now shown to be at 4 of the rhamnose moiety. In addition, a new compound (2), the desacetyl derivative of 1, has also been isolated and identified.
Contribution à la phytochimie du genre Gentiana, XIX. Identification de nouveaux C‐glucosides flavoniques dans Gentiana pyrenaicaL
Authors: Marston Andrew , Hostettmann Kurt , Jacot‐Guillarmod André 
Published: December 2004

Phytochemistry of genus Gentiana, XIX: Identification of new C‐glycosylflavones in Gentiana pyrenaica L.Five flavone C‐glucosides [6‐C‐β‐D‐glucopyranosyl‐tricine (1) or isopyrenine; 7‐O‐β‐D‐glucopyranosyl‐6‐C‐β‐D‐glucopyranosyltricine (2) or isopyrenine‐7‐O‐glucoside; isoscoparine‐7‐O‐glucoside (3); 7‐O‐β‐D‐glucopyranosyl‐6‐C‐β‐D‐glucopyranosylacacetine (4) and isovitexine‐7‐O‐glucoside (5) or saponarine] as well as the flavonol glucoside isoquercitrine (9) have been isolated chromatographically, using polyamide and cellulose columns, from the aerial parts of Gentiana pyrenaica L. 1 and 2 are new compounds and the first glycoflavones trisubstituted on cycle B. Compound 4 is also encountered for the first time in nature.
1,2‐Epoxycarotenoids. Synthesis of the 1′,2′‐Epoxides of β,ψ‐ and ε,ψ‐Carotene (= γ‐ and δ‐Carotene, respectively)
Authors: Pfander Hanspeter , Kamber Matthias 
Published: December 2004

AbstractThe synthesis of the naturally occurring 1′,2′‐epoxy‐1′,2′‐dihydro‐β, δ‐carotene and 1′,2′‐epoxy‐1′,2′‐dihydro‐ε, ψ‐carotene is described.
Effect of Mass Diffusion on Nitration Rates of Moderately Reactive Aromatic Substrates
Authors: Fujiwara Kenji , Tamura Masamitsu , Yoshida Tadao 
Published: December 2004

AbstractCompetitive nitrations of two pairs of aromatic substrates were carried out in order to clarify the effect of several methods of mixing on the observed relative rates. The experimental results indicate that a commercially available four‐jet mixer for rapid reaction could not achieve homogeneous mixing in the competitive nitration of aromatic substrates in aqueous sulfuric acid.
Die heterolytische Fragmentierung von Benzoin‐O‐(carbamoyl)oximen
Authors: Pfoertner Karl‐Heinz , Foricher Joseph , Meister Walter 
Published: December 2004

The Heterolytic Fragmentation of Benzoin‐O‐(carbamoyl)oximesWhile the known heterolytic fragmentation reactions give only three, thermal decomposition of benzoin‐O‐(carbamoyl)oximes results in at least four fragments: nitrile or isocyanide, carbonyl compound, CO2 and amine. This exception is due to the transformation of the nucleofugal group 3 into the unstable carbamic acid and its decomposition (s. Scheme 1). Since only the configuration of benzoin (E)‐O‐(carbamoyl)oximes is satisfactory for concerted reactions, we conclude that the nitrile producing fragmentation of these (E)‐compounds is concerted, whereas in the isocyanide producing fragmentation of the corresponding (Z)‐compounds several steps are involved. – In contrast to the benzoin‐O‐(carbamoyl)oximes the pyrolysis of benzil‐(E)‐O‐(methylcarbamoyl)oxime starts with the elimination of methyl isocyanate and the following fragmentation is that of the oxime.
Total Synthesis of (±)‐3‐Deoxy‐7,8‐dihydromorphine. Preliminary Communication
Authors: Hsu Fu‐Lian , Rice Kenner C. , Brossi Arnold 
Published: December 2004

Abstract(±)‐3‐Desoxy‐7, 8‐dihydromorphin ((±)‐1) wurde aus 3,5‐Dihydroxyphenylessigsäure und 3‐Methoxyphenäthylamin über elf isolierte Zwischenstufen totalsynthetisiert. Als Schlüsselverbindung diente dabei (±)‐N‐Formyl‐2, 4‐dihydroxymorphinan‐6‐on (3). Das daraus über mehrere Zwischenstufen erhaltene (±)‐3‐Desoxy‐6, O‐didehydro‐7, 8‐dihydromorphin ( = N‐Methyl‐4, 5a‐epoxymorphinan‐6‐on, 12), ergab bei der Reduktion mit Lithiumselectrid stereospezifisch das gewünschte (±)‐1, während bei der katalytischen Reduktion und unter energischeren Bedingungen (±)‐4‐Hydroxy‐N‐methylmorphinan‐6‐on ((±)‐2) anfiel. Damit ist die Totalsynthese von 2 realisiert worden.
An Investigation of Charge Effects on NMR. Coupling Constants. The Charge Induced Variation of s‐Densities at the Nucleus
Authors: Kunz Roland W. 
Published: December 2004

AbstractThe dependence of the ns‐density at the nucleus, | ψ ns (0) | 2, on atomic number and charge is examined for the elements helium to radon. The validity of the widely used assumption of a constant valence s‐density at the nucleus, as well as the statement that metal‐phosphorus NMR. coupling constants, 1J (M,P), are strongly influenced by contraction of the phosphorus 3 s orbital is critisized. A possible explanation by rehybridisation within an MO‐framework is offered instead.
The trans‐Influence in Platinum (II) Complexes. 1H‐ and 13C‐NMR. and X‐ray structural studies of tridentate Schiff's base complexes of platinum (II)
Authors: Motschi Herbert , Nussbaumer Cornelius , Pregosin Paul S. , Bachechi Fiorella , Mura Pasquale , Zambonelli Luigi 
Published: December 2004

Abstract1H‐ and 13C‐NMR. data are reported for the complexes [Pt(1)L] and [Pt(2)L]; 1 = OC6H4CH  NCH2CH2O, 2 = OC6H4CH  NC6H4O; L = PR3, AsR3, C  N (cyclohexyl), DMSO, pyridine, secondary amine. The molecular structures of [Pt (2) (NHEt2)] (I) and [Pt (2) (PPh3)] (II) have been determined by X‐ray analysis. Relevant bond distances for I: Pt‐N (amine) = 2.076 Å, Pt‐N (imine) = 2.017 Å, Pt‐O = 1.992 Å and 2.002 Å; for II: Pt‐P = 2.248 Å, Pt‐N = 2.064 Å, Pt‐O = 1.964 and 2.005 Å. Both the solid and solution state data are interpreted in terms of differences in the trans influence of the ligand L. The question of metal‐ligand d‐p π back bonding to the imine is discussed.
Molecular Receptors. Functionalized and chiral macrocyclic polyethers derived from tartaric acid
Authors: Behr Jean‐Paul , Girodeau Jean‐Marc , Hayward Rodney C. , Lehn Jean‐Marie , Sauvage Jean‐Pierre 
Published: December 2004

AbstractA number of functionalized and chiral macrocyclic polyethers have been synthesized by condensation of the dithallium alcoholate of (R,R)‐(+)‐tartaric acid derivatives with α, ω‐dihalides. In this way for instance, the tetracarboxylic [18]‐O6 macrocycle 3c and its derivatives become readily available. They form complexes with various cationic substrates. NMR. and crystal‐structure data provide information about the orientation of the side chains X in 3 with respect to the macrocycle. It is concluded that in the secondary amides like 3b and in their complexes the four X‐groups are preferentially in an axial orientation on the average. This property is of much significance for the design of molecular receptors and catalysts based on this macrocyclic structure. The preparation of a number of other macrocycles is also described.
Stereoselective Syntheses of (±)‐epi‐β‐Santalene and (±)‐epi‐β‐Santalol
Authors: Snowden Roger L. , Sonnay Philippe , Ohloff Güunther 
Published: December 2004

AbstractStereoselective syntheses of (±)‐epi‐β‐santalene (1) and (±)‐epi‐β‐santalol (2), minor constituents of East Indian sandalwood oil, are described. The starting material for both syntheses is the tricyclic hemiacetal 4, readily accessible in two steps from norbornene.
Metal Complexes with Macrocyclic Ligands. XV. The Complexation Kinetics of Open Chain and Cyclic Tetraazaligands with Ni2+ in DMSO and DMF
Authors: Hertli Liselotte , Kaden Thomas A. 
Published: December 2004

AbstractThe complexation kinetics of 2,6,9, 13‐tetraazatetradecane (1), 1,4,8, 11‐tetraazacyclotetradecane (2) and N,N′,N″,N'‐tetramethyl‐1,4,8, 11‐tetraazacyclotetradecane (3) with Ni2+ were studied by the stopped‐flow technique in DMSO and DMF. The biomecular rate constants kLNi (Table 2) follow in both solvents the order 1≳2>3. The similar complexation rates of 1 and 2 in their unprotonated form indicate that for both the open chain and the cyclic ligand the same mechanism holds. By comparison with the solvent exchange the rate determining step of the complexation is the dissociation of the first solvent molecule in the outer‐sphere complex. The lower reactivity of 3 is probably due to steric effects.In the case of 2 a second step in the complexation process was observed and explained by a rearrangement of the ligand already coordinated to the metal ion.
The Configuration of Tricyclo [7.1.1.02,7]undecanes and the Stereochemistry of the Reduction of Tricyclone
Authors: Thomas Alan F. , Thommen Walter , Becker Josef 
Published: December 2004

AbstractA full discussion of the configuration of tricyclo [7.1.1.02,7]undecanes related to cis‐10, 10‐dimethyltricyclo [7.1.1.02,7]undec‐2‐en‐4‐one (2), the Robinson annelation product from norpinone 1 and 3‐buten‐2‐one is given, based on 360‐MHz‐NMR. spectra. Nuclear Overhauser effects confirm the cis configuration of 2, and show that the saturated ketone 10, obtained by catalytic hydrogenation, is also all‐cis with the cyclohexanone ring in the boat conformation. The parent hydrocarbon, cis‐10, 10‐dimethyltricyclo[7.1.1.02,7]undecane is compared with one of the corresponding trans isomers prepared from pinocarvone (14). The stereochemistry of metal hydride reduction and Grignard reaction of 2 is examined.
Reduction of 2‐Bromo‐4, 4‐dimethyl‐2‐cyclohexenone at Mercury. A study on inverted peaks in cyclic voltammetry
Authors: Tissot Paul , Margaretha Paul 
Published: December 2004

AbstractThe parameters which influence the inverted wave appearing in the reverse (oxidation) sweep in the cyclic voltammogramme of the title compound 1 are discussed in detail. The inverted wave is due to the interaction of the reduction products of 1 with the electrode and the electrolyte (TBAFB). The key condition for the presence of the inverted peak is a slow scan rate on the reverse sweep, at least for the last 50 mV before the inversion of the current‐potential curve.
Photochemische Reaktionen. 117. Mitteilung [1] Zur Photochemie von 5,6‐Epoxydienen und konjugierten 5,6‐Epoxytrienen
Authors: Alder Alex Peter , Wolf Hans Richard , Jeger Oskar 
Published: December 2004

Photochemistry of 5,6‐Epoxydienes and of Conjugated 5,6‐EpoxytrienesOn singulet excitation (δ = 254 nm) the 5,6‐epoxydiene 6 and the conjugated 5,6‐epoxytrienes 7 and 8 exclusively give products arising from cleavage of the C, C‐bond of the oxirane (cf. 6→9, 10, 11; 7→ (E)‐15, 16, 17; 8→ 18 (A+B), 19 (A+B), 20, 21). The dihydrofuran compounds 11 and (E/Z)‐15 are formed by cyclization of a ketonium‐ylide a and d, respectively. Photolysis of a gives the carbene b which yields the cyclopropene 9, whereas d forms photochemically the carbenes f and g which yield the methano compounds 16 and 17. The isomeric cyclopropene derivatives 20 and 21 are products of the intermediates h and i, respectively, which are formed by photolysis of the ylide e. The cyclopropene 21 isomerizes by intramolecular cycloadditions to 18 (A+B) and 19 (A+B). ‐ On triplet excitation (λ⩾LD nm; 280 nm; acetone) 6 undergoes cleavage of the C(5), O‐bond and isomerizes to 12 and 14. However, 7 is converted by cleavage of the C, C‐bond of the oxirane to yield 15. On treatment with BF3O(C2H5)2 6 gives 14, whereas 7 yields 22, and 8 forms 23 and 24.
Photochemische Reaktionen. 118. Mitteilung [1] Zur vinylogen β‐Spaltung von Enonen. UV.‐Bestrahlung von 4‐(3',7',7'‐Trimethyl‐2'‐oxabicyclo [3.2.0]hept‐3'‐en‐1'‐yl)but‐3‐en‐2‐on
Authors: Murato Kazuo , Wolf Hans Richard , Jeger Oskar 
Published: December 2004

Vinylogous β‐Cleavage of Enones: UV.‐irradiation of 4‐(3′,7′,7′‐trimethyl‐2′‐oxabicyclo[3.2.0]hept‐3′‐ene‐1′‐yl)but‐3‐ene‐2‐onOn 1π,π*‐excitation (λ = 254 nm) in acetonitrile (E/Z)‐2 is converted into the isomers 4–9 and undergoes fragmentation yielding 10; in methanol (E/Z)‐2 gives 7–10 and is transformed into 11 by incorporation of the solvent.On 1π,π*‐excitation (λ λ⩾347 nm; benzene‐d6) (E)‐2 is isomerized into (Z)‐2, which is converted into the isomers 3 and 4 by further irradiation.1π,π*‐Excitation (λ = 254 nm; acetonitrile) of 4 gives 6 and (E)‐9, whereas UV.‐irradiation (λ = 254 nm; acetonitrile‐d3) of 5 yields (E)‐7 and 8.On 1π,π*‐excitation (λ = 254 nm; acetonitrile) of (E/Z)‐12 the compounds (E)‐14 and (E)‐15 are obtained.
Crystal Structures of rac‐Methyl‐ (3R*, 3aS*, 4R*, 7R*, 7aR*)‐7‐Acetoxymethyl)‐3‐benzyl‐4,5‐dimethyl‐1‐oxo‐3a,4,7,7a‐tetrahydroisoindoline‐7a‐carboxylate
Authors: Zehnder Margareta 
Published: December 2004

AbstractThe X‐ray structures of the compounds 4 and 2 have been determined by direct methods and refined by least squares techniques. Crystals of C22H27NO5 and C27H27NO5 are triclinic, space groups PĪ with lattice parameters a = 13.652 (5) Å, b = 10.926 (3) Å, c = 7.755 (2) Å, a = 111.554 (4) Å, β = 85.541 (3) Å, γ = 104.813 (4) Å, and a = 15.394 (4) Å, b = 9.674 (3) Å, c = 8.522 (3) Å, a = 111.04 (4) Å, ß = 93.65 (4) Å, γ = 95.01 (4) Å, respectively.
ESR. Study of an X‐Irradiated Single Crystal of Methylene Diarsonic Acid
Authors: Geoffroy Michel , Llinares Antoine 
Published: December 2004

AbstractX‐Irradiation of single crystals of methylene diarsonic acid gives rise to a variety of radicals which have been identified by ESR. spectroscopy; (OH)2As(O)CHAs(O) (OH)2, −OÅs(OH)2CH2As(O)(OH)2, AsO3– and (OH)Ås(O)CH2As(O)(OH)2. The spin densities have been obtained from the 75As‐hyperfine tensors. An additional species ‐ probably a radical anion localized on a pentacoordinated arsenic ‐ is also detected after annealing at room temperature. The radiation damage process is discussed.
Absorption Spectra and Termination Kinetics of Transient Free Radicals in Solution Observed by UV./VIS. Spectroscopy with modulated excitation
Authors: Huggenberger Christian , Fischer Hanns 
Published: December 2004

AbstractFree radicals are generated in liquid solutions by harmonically modulated photolysis of suitable substrates. Harmonic analysis of the absorbance as functions of wavelength and modulation frequency yields the optical spectra and the decay kinetics of the transient species. The experimental technique and the analysis are described in detail. Results on t‐butyl, 2‐propyl and benzyl radicals generated by photolysis of the corresponding dialkyl resp. dibenzyl ketones are reported. They confirm previous spectral assignments and show that the termination reactions are diffusion controlled.
1,1‐Dihalogenoanthra [b]cyclopropenes. Preliminary communication
Authors: Müuller Paul , Rey Michel 
Published: December 2004

Abstract1,1‐Dichloro‐ and 1,1‐difluoroanthra [b]cyclopropene (1 and 2) are synthesized in 8 steps from the Diels‐Alder adduct of benzocyclobutene and maleic anhydride.
Studies on the Conversions of Diols and Cyclic Ethers. Part 48. Dehydration of alcohols and diols on the action of dimethylsulfoxide
Authors: Molnár Árpád , Bartók Mihály 
Published: December 2004

AbstractThe transformations of 13 alcohols and 13 diols in the presence of a small amount dimethylsulfoxide (1/16 mol) were studied. Relationships were found between the type of the hydroxy compound and the selectivity of the transformation, and conclusions were drawn regarding the transformation mechanism. The ether formation observed with certain alcohols proceeds via a carbenium cation. The reaction conditions applied were found suitable for inducing water elimination from the ditertiary 1,2‐ and 1,3‐diols (pinacol rearrangement, 1,2‐elimination). From the 1,4‐ and 1,5‐diols the corresponding oxacycloalkanes can be obtained in good yield. Cyclodehydration occurs by intramolecular nucleophilic substitution, via a concerted mechanism. The effect of DMSO is exerted directly, and protoncatalysis occurs simultaneously.
Stoffwechselprodukte von Mikroorganismen. 202. Mitteilung. Strukturaufklärung von Elaiophylin: Spektroskopische Untersuchungen und Abbau
Authors: Kaiser Hanspeter , Keller‐Schierlein Walter 
Published: December 2004

Structure Elucidation of Elaiophylin: Spectroscopy and Chemical DegradationThe structure of the antibiotic elaiophylin (azalomycin B) was elucidated by extended spectroscopic investigations and chemical degradation. Elaiophylin (26) is a macrodiolide with a 16membered dilactone ring. The synthesis of 7‐acetoxy‐6‐ethyl‐3‐octanone (14), the acetyl derivative of an important degradation product, is described.
‘Through Space’ and ‘Through Bond’ Interactions in [2.2]Cyclopanes; the Assignment of their Photoelectron Spectra
Authors: Kovač Branka , Allan Michael , Heilbronner Edgar 
Published: December 2004

AbstractThe photoelectron spectra (PE.) of ten cyclophanes (7 to 14, 16, 18) have been assigned on the basis of a simple molecular orbital model proposed recently for the cyclophanes 2 (1,4) to 6. It is shown that the agreement between calculated and observed band positions provides strong evidence for the validity of the model.
Dediazoniation of Arenediazonium Ions in Homogeneous Solutions. Part XVI. Kinetics and mechanisms of dediazoniation of p‐chlorobenzenediazonium tetrafluoroborate in weakly alkaline aqueous solutions under nitrogen gas
Authors: Schwarz Wolfgang , Zollinger Heinrich 
Published: December 2004

AbstractThe kinetics of reactions of p‐chlorobenzenediazonium ions in aqueous buffer solutions (pH 9.0–10.6) under N2 (< 5 ppb of O2) have been measured between 20 and 50°C. The formation of trans‐diazotate is first‐order with respect to the concentration of hydroxyl ions and to the equilibrium concentration of diazonium ions, if the diazonium ion⇄cis‐diazotate equilibrium is considered as a fast prior equilibrium. This indicates that the p‐chlorobenzenediazonium ion, in contrast to all previous investigations with the p‐nitrobenzenediazonium ion and benzenediazonium ions carrying similar substituents with a −M effect, rearranges from the cis‐ to the trans‐configuration as diazohydroxide and not as diazotate. The formation of trans‐diazotate is catalyzed by carbonate and inhibited by hydrogen carbonate ions; mechanisms of these catalyses are discussed, and the solvent isotope effect KH2O/KD2O measured by an 1H‐NMR. technique reported. The kinetics of the dediazoniations can be analyzed as a mixture of two reactions, a relatively fast first reaction, reaction A, which is responsible for about 5% of the total reaction, and a second reaction F. Both are first‐order with respect to diazonium ion; reaction A is also first‐order in hydroxyl ions. There are some indications that reaction A corresponds to the hydrolysis of the diazonium ion to give eventually amine and nitrite ions. Reaction F shows a complex dependence on hydroxyl ions; it is related to the homolytic dediazoniation.
Dediazoniation of Arenediazonium Ions in Homogeneous Solutions. Part XVII. Kinetics and mechanisms of dediazoniation of p‐chlorobenzenediazonium tetrafluoroborate in weakly alkaline aqueous solutions in the presence of oxygen
Authors: Besse Jacques , Zollinger Heinrich 
Published: December 2004

AbstractThe kinetics of dediazoniation of p‐chlorobenzenediazonium tetrafluoroborate have been studied in buffer solutions in the pH‐range 9.0–10.0, ionic strength I = 0.10, at 20.0° in glass and polytetrafluoroethylene vessels. The presence of oxygen (<5 ppb of O2, 60 to 100 ppb of O2, air, > 99% of O2) has a decisive influence on the rate and kinetic order of the dediazoniation. Iodoacetic acid inhibits the reaction, whereas p‐chlorophenol has a catalytic effect, and in air and >99% of O2 it acts as an autocatalyst. The reaction is subject to general‐base catalysis by water, hydroxyl ions, hydrogen carbonate and carbonate ions. The kinetic results are interpreted in conjunction with data concerning the reaction products [2] and a 15N‐CIDNP. investigation of a related system [3]. Specific radical chain mechanisms are consistent with the results.
Notizen zur Synthese sulfonierter Derivate von 5,6,7,8‐Tetrahydro‐1‐naphthylamin und 5,6,7,8‐Tetrahydro‐2‐naphthylamin
Authors: Courtin Alfred 
Published: December 2004

Notes on the Synthesis of Sulfonated Derivatives of 5,6,7,8‐Tetrahydro‐1‐naphthylamine and 5,6,7,8‐Tetrahydro‐2‐naphthylamineSulfonation of 5,6,7,8‐tetrahydro‐1‐naphthylamine (1) with sulfuric acid gave a mixture of 1‐amino‐5,6,7,8‐tetrahydronaphthalene‐2‐sulfonic acid (2), 4‐amino‐5,6,7,8‐tetrahydronaphthalene‐2‐sulfonic acid (13) and 4‐amino‐5,6,7,8‐tetrahydronaphthalene‐1‐sulfonic acid (3). The same reaction with 5,6,7,8‐tetrahydro‐2‐naphthylamine (20) yielded 3‐amino‐5,6,7,8‐tetrahydronaphthalene‐2‐sulfonic acid (21); formation of 2‐amino‐5,6,7,8‐tetrahydronaphthalene‐1‐sulfonic acid (16) or of 3‐amino‐5,6,7,8‐tetrahydronaphthalene‐1‐sulfonic acid (24) was not observed. Treatment of 4‐bromo‐5,6,7,8‐tetrahydro‐1‐naphthylamine (4) or of its 4‐chloro analogue 5 with amidosulfuric acid gave 1‐amino‐4‐bromo‐5,6,7,8‐tetrahydronaphthalene‐2‐sulfonic acid (9) and its 4‐chloro analogue 10, respectively, which were dehalogenated to 2. Preparations of 13 and 24 were achieved by sulfonation of 5‐nitro‐1,2,3,4‐tetrahydronaphthalene (14) and 6‐nitro‐1,2,3,4‐tetrahydronaphthalene (22) to 4‐nitro‐5,6,7,8‐tetrahydronaphthalene‐2‐sulfonic acid (15) and 3‐nitro‐5,6,7,8‐tetrahydronaphthalene‐1‐sulfonic acid (23), respectively, followed by Béchamp reductions. The sulfonic acid 13 was also obtained by hydrogenolysis of 4‐amino‐1‐bromo‐5,6,7,8‐tetrahydronaphthalene‐2‐sulfonic acid (11) or of its 1‐chloro analogue 12; compounds 11 and 12 were synthesized from N‐(4‐bromo‐5,6,7,8‐tetrahydro‐1‐naphthyl)acetamide (7) and from its 4‐chloro analogue 8, respectively, by sulfonation with oleum and subsequent hydrolysis. By ‘baking’ the hydrogensulfate salt of 1 or 20 compounds 3 and 21 were obtained, respectively. Synthesis of 16 was achieved by sulfur dioxide treatment of the diazonium chloride derived from 2‐nitro‐5,6,7,8‐tetrahydro‐1‐naphthylamine (17) giving 2‐nitro‐5,6,7,8‐tetrahydronaphthalene‐1‐sulfonyl chloride (18), followed by hydrolysis of 18 to the corresponding sulfonic acid 19 and final reduction.
2‐Bis (dimethylamino)phosphinoyl‐1‐lithio‐1, 2, 3, 4‐tetrahydroisoquinoline. A highly nucleophilic d1‐reagent for the preparation of 1‐substituted tetrahydroisoquinolines
Authors: Seebach Dieter , Yoshifuji Masaaki 
Published: December 2004

AbstractThe title compound 4 is generated from the phosphoric amide 5 in tetrahydrofuran with butyllithium. The lithium reagent 4 is stable at room temperature; its reactions with electrophiles furnish the products 6–22, 26, 27, see Table 1 and the Scheme. A second alkylation is also possible, see 23–25. The cleavage to tetrahydroisoquinolines is accomplished in refluxing aqueous‐methanolic hydrochloric acid, see Table 2. Phosphinoylation, lithiation, reaction with electrophiles and cleavage constitute an efficient sequence for 1‐alkylation of the isoquinoline nucleus.