Showing papers in "Journal of The Chemical Society, Chemical Communications in 1978"
TL;DR: In this paper, N-Acetyl-D,L-penicillamine (1) was converted by HNO2 into a thionitrite (3) which was stable as a solid and atypically so even in solution.
Abstract: N-Acetyl-D,L-penicillamine (1) was converted by HNO2 into a thionitrite (3) which was stable as a solid and atypically so even in solution; X-ray structural parameters are given for (3), and both homolytic and heterolytic reactions are described.
272 citations
TL;DR: Use of base-labile N-fluorenylmethoxycarbonylamino-acids, t-butyl based side chain protecting groups, and a p-alkoxybenzyl ester resin linkage provides a simple, rapid, and exceptionally mild strategy in solid phase peptide synthesis.
Abstract: Use of base-labile N-fluorenylmethoxycarbonylamino-acids, t-butyl based side chain protecting groups, and a p-alkoxybenzyl ester resin linkage provides a simple, rapid, and exceptionally mild strategy in solid phase peptide synthesis.
231 citations
TL;DR: In this article, the reduction of αβ-unsaturated ketones with sodium borohydride in methanol solution in the presence of cerium chloride gives almost exclusively the allylic alcohol, sometimes stereoselectively.
Abstract: The reduction of αβ-unsaturated ketones with sodium borohydride in methanol solution in the presence of cerium chloride gives almost exclusively the allylic alcohol, sometimes stereoselectively; the reduction of a variety of natural products containing a conjugated keto-group is described.
213 citations
TL;DR: In this paper, the terdentate ligand 2,6-(Me2NCH2)2C6H3) undergoes with MeI (M = Pt, X = BF4) oxidative addition and consecutive reductive elimination resulting in the formation of the complex BF4−[IPt[graphic omitted]R-Me]+ in which the C-aryl center, at which C-C coupling has occurred, is bonded to the cationic Pt-centre by a novel Pt-to-C-interaction.
Abstract: Square-planar complexes of the type R[graphic omitted]MX (M = Pt or Pd), containing the terdentate ligand 2,6-(Me2NCH2)2C6H3, undergo with MeI (M = Pt, X = BF4) oxidative addition and consecutive reductive elimination resulting in the formation of the complex BF4–[IPt[graphic omitted]R-Me]+ in which the C-aryl centre, at which C–C coupling has occurred, is bonded to the cationic Pt-centre by a novel Pt-to-C-interaction.
149 citations
TL;DR: In this article, an experimental technique is described which identifies the chemical shifts of directly bonded protons and carbon-13 nuclei and presents the result in the form of a shift correlation map.
Abstract: An experimental technique is described which identifies the chemical shifts of directly bonded protons and carbon-13 nuclei and presents the result in the form of a shift correlation map.
143 citations
TL;DR: In this paper, a Ziegler-Natta-based mechanism for the stereospecific polymerization of olefins was proposed, which differs significantly from previous mechanisms in the proposal that it proceeds via a 1,2-hydrogen shift from the α-carbon of the polymer chain and formation of metallocycle and carbene intermediates.
Abstract: A mechanism for the stereospecific polymerization of olefins by Ziegler–Natta catalysts is developed which differs significantly from previous mechanisms in the proposal that it proceeds via a 1,2-hydrogen shift from the α-carbon of the polymer chain and formation of metallocycle and carbene intermediates.
129 citations
TL;DR: The microwave spectrum of glycine vapour has been measured and analyzed as mentioned in this paper, and it is in the molecular form with a dipole moment of 4·5-4·6 D and probably having conformation (4), which is in conflict with a recent theoretical study that implies that conformation is more stable.
Abstract: The microwave spectrum of glycine vapour has been measured and analysed; it is in the molecular form with a dipole moment of 4·5–4·6 D and probably having conformation (4), which is in conflict with a recent theoretical study that implies that conformation (3) is more stable.
124 citations
TL;DR: In this paper, the metal-to-ligand charge transfer excited states of several CuI complexes give rise to photoluminescence which appears to originate from the charge-transfer excited states.
Abstract: Exciting the metal-to-ligand charge transfer excited states of several CuI complexes gives rise to photoluminescence which appears to originate from the charge transfer excited states.
117 citations
TL;DR: The synthesis and diverse conductivity properties of the tetracyanoquinodimethane (TCNQ) complexes of several tetrakis-(alkylthio)-tetrathiafulvalenes are described in this article.
Abstract: The synthesis and diverse conductivity properties of the tetracyanoquinodimethane (TCNQ) complexes of several tetrakis-(alkylthio)-tetrathiafulvalenes are described, and compared with those of tetrathiafulvalene-TCNQ and related complexes.
115 citations
TL;DR: Tetrabutylammonium permanganate is an easily prepared crystalline stable compound soluble in organic solvents; its use for oxidations of organic substrates in pyridine under mild conditions is described in this paper.
Abstract: Tetrabutylammonium permanganate is an easily prepared crystalline stable compound soluble in organic solvents; its use for oxidations of organic substrates in pyridine under mild conditions is described.
111 citations
TL;DR: In this article, the first example of a homogeneous catalytic oxidation of an amino-group was presented, where a trichloride was used to catalyze secondary alcohols to ketones, primary amines to nitriles, and 2-aminoalkanes to imines by O2.
Abstract: Ruthenium trichloride catalyses the homogeneous oxidation of secondary alcohols to ketones, primary amines to nitriles, and 2-aminoalkanes to imines by O2; this is the first example of a homogeneous catalytic oxidation of an amino-group.
TL;DR: The structure of staurosporine (1), a new alkaloid from a Streptomyces strain, has been established by X-ray crystallography.
Abstract: The structure of staurosporine (1), a new alkaloid from a Streptomyces strain, has been established by X-ray crystallography.
Abstract: Allyl alkyl (and aryl) ethers are isomerised by H2-activated [Ir(cyclo-octa-1,5-diene)(PMePh2)2]PF6 in tetrahydrofuran or dioxan at room temperature to the corresponding trans-propenyl ethers (yields 95%; stereoselectivity 97%).
TL;DR: In this paper, the modified peptide antibiotics micrococcin P1 and P2 are proposed on the basis of chemical and spectroscopic evidence, and biogenetic implications discussed.
Abstract: Structures for the modified peptide antibiotics micrococcin P1 and P2 are proposed on the basis of chemical and spectroscopic evidence, and biogenetic implications discussed.
TL;DR: In this article, the ionic structures of the neutral and ionic [Li(L)4]-[MR4][R = Me3SiCH2, when M = Tb, Er, or Yb, L2= Me2NCH2CH2NMe2(tmed), and when L2 = 0·5 tmed or thf, their structures were deduced from a single crystal X-ray analysis.
Abstract: The neutral [M(CH2SiMe3)3(thf)2](M = Tb, Er, or Yb; thf = tetrahydrofuran) and the ionic [Li(L)4]-[MR4][R = Me3SiCH2; when M = Y, Er, or Yb, L2= Me2NCH2CH2NMe2(tmed); when M = Y, L = thf], [Li(thf)4][M(Cl)R3][M = Er or Yb, R =(Me3Si)2CH], and [LiL2][M(η-C5H4SiMe3)2Cl2][L = 0·5 tmed or thf) are reported; their structures are deduced from i.r. and 13C and 1H n.m.r. (M = Y) spectra, conductivity, and in the case of [Li(thf)4][Yb{CH(SiMe3)2}3Cl], by a single crystal X-ray analysis [l(Yb–C)(av.)= 2·38 A].
TL;DR: A method for the introduction of guanidinium groups into macrocyclic molecules has been developed and applied to the synthesis of three such macrocycles (1, (3), and (5) which display enhanced binding of phosphate anion as discussed by the authors.
Abstract: A method for the introduction of guanidinium groups into macrocyclic molecules has been developed and applied to the synthesis of three such macrocycles (1), (3), and (5) which display enhanced binding of phosphate anion.
TL;DR: The pentapeptide Tos-(Aib)5-OMe adopts a 310 helical conformation in the solid state, with three consecutive Type III B-turns stabilized by intramolecular hydrogen bonds as discussed by the authors.
Abstract: The pentapeptide Tos-(Aib)5-OMe adopts a 310 helical conformation in the solid state, with three consecutive Type III B-turns stabilized by intramolecular hydrogen bonds.
TL;DR: In this paper, the reaction of the alkyl carbamates with trimethylsilyl iodide (TSI) followed by methanolysis of the resulting trimethyl silyl carbamide is shown to yield high yields of the corresponding amines, even in the case of very sensitive compounds.
Abstract: Reaction of the alkyl carbamates (1) with trimethylsilyl iodide (2) followed by methanolysis of the resulting trimethylsilyl carbamates (4), affords high yields of the corresponding amines (5), even in the case of very sensitive compounds such as 2,3-diazabicyclo[2.2.1]heptane (5h).
TL;DR: In this paper, the enantiomeric yield of chiral products was found to be inversely proportional to the dielectric constant of the solvent in a number of 1,4-addition reactions.
Abstract: In a number of 1,4-addition reactions yielding chiral products through asymmetric catalysis the enantiomeric yield of products was found to be inversely proportional to the dielectric constant of the solvent.
TL;DR: Use of base-labile fluorenylmethoxycarbonyl-amino-acids enables solid phase peptide synthesis of human β-endorphin to be carried out under much milder reaction conditions than formerly with improvement in product purity and yield.
Abstract: Use of base-labile fluorenylmethoxycarbonyl-amino-acids enables solid phase peptide synthesis of human β-endorphin to be carried out under much milder reaction conditions than formerly with improvement in product purity and yield.
TL;DR: The oxime of isopropyl phenyl ketone (Z-isomer) with NaOAc-Na2PdCl4 gives [Pd3(ONCPriPh)6] as discussed by the authors.
Abstract: The oxime of isopropyl phenyl ketone (Z-isomer) with NaOAc–Na2PdCl4 gives [Pd3(ONCPriPh)6] and whereas pinacolone oxime carbopalladates regiospecifically on the t-butyl group, the dimethylhydrazone carbopalladates only on the methyl group: acetone oxime O-allyl ether palladates on the central carbon atom of the allyl group with nucleophilic attack (e.g. by OMe–) on the terminal carbon atom.
TL;DR: According to X-ray study the complex of stoicheiometry AcO·Pd·CO, prepared from Pd(OAc)2 and CO, consists of tetranuclear clusters with two short and two long Pd-Pd bonds.
Abstract: According to X-ray study the complex of stoicheiometry AcO·Pd·CO, prepared from Pd(OAc)2 and CO, consists of tetranuclear clusters with two short and two long Pd–Pd bonds.
TL;DR: Asymmetric induction in the Michael addition of nitromethane to chalcone was greatly enhanced from 1% to ca. 20% by replacing as catalyst a chiral amine in methanol by its aminium fluoride salt in an aprotic solvent.
Abstract: Asymmetric induction in the Michael addition of nitromethane to chalcone is greatly enhanced from 1% to ca. 20% by replacing as catalyst a chiral amine in methanol by its aminium fluoride salt in an aprotic solvent.
TL;DR: The fully characterised group 3A and lanthanoid metal complexes [M(η-C5H4R)2Me]2(M;Y or Er, RH, Me, or SiMe3, and MYb, RH or Me) are active homogenous ethylene polymerisation catalysts; they show an intramolecular deactivation process involving abstraction of a cyclopentadinyl hydrogen which is completely suppressed with peralkylated derivatives as mentioned in this paper.
Abstract: The fully characterised group 3A and lanthanoid metal complexes [M(η-C5H4R)2Me]2(M;Y or Er, RH, Me, or SiMe3, and MYb, RH or Me) and [M(η-C5H4R)2Me2AlMe2](MY, Er, Ho, or Yb RH or Me, and MY, RSiMe3) are active homogenous ethylene polymerisation catalysts; they show an intramolecular deactivation process involving abstraction of a cyclopentadinyl hydrogen which is completely suppressed with peralkylated derivatives.
TL;DR: The first example of a first-stage boron nitride salt was reported in this article. But this was a first stage graphite salt, and it was not the first instance of a borone nitride (BN)4+SO3F.
Abstract: Graphite is oxidized by O2+AsF6– and by OsF6 to give first-stage graphite salts C8+MF6–; S2O6F2 oxidizes both graphite and boron nitride to yield the salts C12+-SO3F– and (BN)4+SO3F–, the latter being the first example of a first-stage boron nitride salt.
TL;DR: The macrocyclic molecular catalyst complexes primary ammonium ester salts and displays enhanced rates of intramolecular thiolysis of the bound substrates with structural selectivity for dipeptide esters and high chiral recognition for the (L) antipode of the enantiomeric glycyl–phenyl–alanine esters.
Abstract: The macrocyclic molecular catalyst (1) complexes primary ammonium ester salts and displays enhanced rates of intramolecular thiolysis of the bound substrates with structural selectivity for dipeptide esters and high chiral recognition for the (L) antipode of the enantiomeric glycyl–phenyl–alanine esters.
TL;DR: The β-(trimethylsilyl)ethoxycarbonyl amino-protecting group was de-blocked in acetonitrile at 50 °C by the specific reagent tetraethylammonium fluoride with the formation of gaseous by-products.
Abstract: The β-(trimethylsilyl)ethoxycarbonyl amino-protecting group is de-blocked in acetonitrile at 50 °C by the specific reagent tetraethylammonium fluoride with the formation of gaseous by-products.
TL;DR: In this paper, C2-oxygenated compounds composed mainly of ethanol were catalytically produced from CO and H2 under atmospheric pressure over pyrolysed Rh carbonyl clusters dispersed on specific metal oxides such as TiO2, ZrO2 and La2O3.
Abstract: C2-oxygenated compounds composed mainly of ethanol were catalytically produced from CO and H2 under atmospheric pressure over pyrolysed Rh carbonyl clusters dispersed on specific metal oxides such as TiO2, ZrO2, and La2O3.
TL;DR: The pixyl group may be removed by acidic hydrolysis under very mild conditions as discussed by the authors, but only under mild conditions, and only under the conditions of very mild acidity.
Abstract: 9-Chloro-9-phenylxanthene (4b) reacts with the 5′-hydroxy groups of 2′-deoxyribonucleosides (2)(and their N-acyl derivatives) to give crystalline 9-phenylxanthen-9-yl (pixyl) derivatives (5) in satisfactory to good yields; the pixyl group may be removed by acidic hydrolysis under very mild conditions.