Search results for "element"

ChemInform Abstract: Efficient Stereoselective Synthesis of Boron L-amino Acid Derivatives Using Wittig and Borylation Reactions

2015

The stereoselective synthesis of a new classes of boronato- or trifluoroborato aminoacids and peptides was described using Wittig and C-H iridium borylation as key reactions. A trifluoroborato-thio...

1981

C−C versus C−N Annulation Reactions of 2-Alkyl-2-oxazolines and 2-Alkyl-2-thiazolines: A Simple Synthesis of Novel 3-Aminoindene, Phthalimidine, Pyrr…

2001

The effect of various aromatic and aliphatic dielectrophiles on the lithium azaenolates of 2-alkyl-2-oxazolines and 2-alkyl-2-thiazolines has been examined. This effect varies greatly, depending on the nature of the dielectrophile used. 3-Aminoindene (3) and 3-alkylidenephthalimidine (4−5) derivatives were formed as a result of the reactions with dielectrophiles derived from ortho-substituted benzonitriles. Similarly, 2-alkylidenepyrrolidine (7) and 2-alkylidenepiperidine (8) derivatives were obtained in high yields from 2-alkyl-2-oxazolines or 2-alkyl-2-thiazolines and aliphatic dielectrophiles derived from ω-haloalkyldiphenylacetonitrile. C−C versus C−N annulation reactions are discussed.

ChemInform Abstract: C-C versus C-N Annulation Reactions of 2-Alkyl-2-oxazolines and 2-Alkyl-2-thiazolines: A Simple Synthesis of Novel 3-Aminoindene…

2010

The effect of various aromatic and aliphatic dielectrophiles on the lithium azaenolates of 2-alkyl-2-oxazolines and 2-alkyl-2-thiazolines has been examined. This effect varies greatly, depending on the nature of the dielectrophile used. 3-Aminoindene (3) and 3-alkylidenephthalimidine (4−5) derivatives were formed as a result of the reactions with dielectrophiles derived from ortho-substituted benzonitriles. Similarly, 2-alkylidenepyrrolidine (7) and 2-alkylidenepiperidine (8) derivatives were obtained in high yields from 2-alkyl-2-oxazolines or 2-alkyl-2-thiazolines and aliphatic dielectrophiles derived from ω-haloalkyldiphenylacetonitrile. C−C versus C−N annulation reactions are discussed.

ChemInform Abstract: Palladium-Catalyzed Synthesis of Mono- and Diphosphorylated 1,10-Phenanthrolines.

2013

A general protocol for the coupling of mono- and dihalo-1,10-phenanthrolines with diethyl phosphite is reported. This reaction proceeds smoothly in the presence of a Pd(OAc)2/dppf catalytic system and triethylamine as a base.

A New Layered Compound Containing [PMo12O40]3- and Both 5- and 6-Coordinated Homoleptic (1-(2-Chloroethyl)tetrazole)Copper(II) Cations

2002

The synthesis, crystal structure and physical properties of the complex obtained from the reaction between the polyoxometalate anion [PMo12O40]3- copper(II) and the ligand 1-(2-chloroethyl)tetrazole (teec) are described. This compound has been synthesized as a model for designing materials containing both magnetic polyoxometalate anions and iron(II) spin-crossover cations. Keywords. Coordination chemistry; Heterocycles; Polyoxometalates; Structure elucidation; Tetrazole.

Polyenolates of unsaturated carboxylic acids in synthesis. A straightforward synthesis of retinoic acids.

1990

Abstract Retinoic acids are prepared in a two step procedure by addition of lithium trienediolates of sorbic acid and 3-methyl-sorbic acid to β-ionone.

Spin Polarization and Ferromagnetism in Two-Dimensional Sheetlike Cobalt(II) Polymers: [Co(L)2(NCS)2] (L=Pyrimidine or Pyrazine)

1998

Polyenolates of Unsaturated Carboxylic Acids in Synthesis. Synthesis of Unsaturated α-Amino Acids and β-Hydrazing Acids

1991

Abstract Regioselective reaction of lithium diene-and triene-diolates 1 and 2 with O-diphenylphosphinyl hydroxylamine affords unsaturated α-amino acids 3 and 4. Addition to DEAD leads selectively to γ-hydrazino unsaturated acids 5 and 6.

Chemical Carcinogenesis by Polycyclic Aromatic Hydrocarbons

1982

The realization that for a vast number of toxic effects, not the given compound itself was responsible but rather a metabolite that was produced from the compound, brought about an enormous step forward in chemical carcinogenesis and in toxicology in general (1–15). In chemical mutagenesis and in chemical carcinogenesis very often coumpounds, which by themselves are chemically inert, will produce mutagenic and carcinogenic effects. A prime example of this is the polycyclic aromatic hydrocarbons, which consisting of condensed aromatic rings are chemically inert, yet do produce mutagenic and carcinogenic effects. During the last 10 to 20 years researchers have started to realize that this is …