A Mössbauer study of organotellurium compounds. Part III. Tellurium heterocycles and related compounds

1978 ◽  
Vol 56 (13) ◽  
pp. 1746-1751 ◽  
Author(s):  
Nigel S. Dance ◽  
Colin H. W. Jones
Keyword(s):  
Heterocyclic Compounds ◽  
Mössbauer Study ◽  
Ring Systems ◽  
Mössbauer Parameters ◽  
Mössbauer Data ◽  
Related Compounds ◽  
Organotellurium Compounds

Mössbauer data are reported for a number of heterocyclic compounds containing tellurium. The influence on the Mössbauer parameters of the constraints imposed by accommodating tellurium in these ring systems are discussed. The influence of the bulky aryl ligand 2-biphenylyl, C12H9—, on the Mössbauer parameters of diaryltellurium dihalides and aryltellurium trihalides has also been investigated.

A Mössbauer study of organotellurium compounds. Part I

1976 ◽  
Vol 54 (20) ◽  
pp. 3234-3241 ◽  
Author(s):  
Colin H. W. Jones ◽  
Robert Schultz ◽  
William R. McWhinnie ◽  
Nigel S. Dance
Keyword(s):  
Additive Model ◽  
Mössbauer Study ◽  
Wide Range ◽  
Mössbauer Data ◽  
Organotellurium Compounds

Mössbauer data for a wide range of organotellurium compounds are reported, including compounds of the type: R2Te, Ar2Te, Ar2Te2, R2TeX2, Ar2TeX2, and ArTeX3; where R = alkyl, Ar = aryl, and X = Cl, Br, or I. The isomer shifts and quadrupole splittings are interpreted in terms of the relative populations of the tellurium 5s and 5p orbitals. The quadrupole splittings are rationalized in terms of a simple additive model, formulated within the framework of the Townes and Dailey theory.

A Mössbauer study of organotellurium compounds. Part II. Halides, acetates, and benzoates

1976 ◽  
Vol 54 (23) ◽  
pp. 3737-3742 ◽  
Author(s):  
Frank J. Berry ◽  
Colin H. W. Jones
Keyword(s):  
The Other ◽  
Mössbauer Study ◽  
Mössbauer Data ◽  
Organotellurium Compounds

125Te Mössbauer data, measured at 4.2 K, are reported for a number of organotellurium(IV) compounds, including Ar2TeF2, ArTeF3, Ar2Te(OCOCH3)2, Ar2Te(OCOC6H5)2, where Ar = Ph, p-EtOC6H4, p-MeOC6H4, p-C7H7, and the compounds Ph2(CH3)TeI and Ph(CH3)2TeI. Evidence is presented that while the difluorides appear to be similar in structure to the other dihalides(X = Cl, Br, I), in the trifluorides the co-ordination about the tellurium is significantly different to that found in the other trihalides (X = Cl, Br, I). The iodides studied have parameters consistent with their formulation as Ph2(CH3)Te+I− and Ph(CH3)2Te+I−. The dicarboxylates have parameters similar to those of the dihalides, although the diphenyl tellurium diacetate and dibenzoate have relatively small Δ's in comparison with those of the other derivatives studied and it would appear that subtle changes in the co-ordination about tellurium occur with changes in the aryl ligand.

l-Prolinal Dithioacetal: A Highly Effective Organocatalyst for the Direct Nitro-Michael Addition to Selected Cyclic and Aromatic Ketones

Synthesis ◽  
2019 ◽  
Vol 51 (17) ◽  
pp. 3356-3368
Author(s):  
Piotr Pomarański ◽  
Zbigniew Czarnocki
Keyword(s):  
Michael Addition ◽  
Ring Size ◽  
Cyclic Ketones ◽  
Asymmetric Syntheses ◽  
Aromatic Ketones ◽  
Ring Systems ◽  
Effective Catalyst ◽  
Acetophenone Derivatives ◽  
Highly Effective ◽  
Related Compounds

The synthesis of novel l-prolinal dithioacetal and its application as an organocatalyst for the direct Michael addition of cyclic ketones and acetophenone derivatives to trans-β-nitrostyrene and related compounds is described. The prolinal dithioacetal acts as effective catalyst in the case of cyclic ketones of different ring size, in particular five- and six-membered examples, as well as larger and smaller ring systems. High enantioselectivity and diastereoselectivity is observed for different substrates and trans-β-nitrostyrenes. Also, the first asymmetric syntheses of selected 2-methyl-4-nitro-1,3-diphenylbutan-1-one derivatives by application of the obtained organocatalyst is presented.

A 19F, 119Sn nuclear magnetic resonance and 119Sn Mössbauer study of the SnF2–MF–H2O system

1984 ◽  
Vol 62 (3) ◽  
pp. 591-595 ◽  
Author(s):  
Thomas Birchall ◽  
Georges Dénès
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Spectroscopic Data ◽  
Dominant Species ◽  
Mössbauer Study ◽  
Frozen Solution ◽  
Nmr Data ◽  
Mössbauer Measurements ◽  
Mössbauer Parameters ◽  
High Concentrations ◽  
Frozen Solutions

19F and 119Sn nmr spectroscopy has been used to study the SnF2–MF–H2O (M = Li+, Na+, K+, Rb+, Cs+, and [NH4]+) system. The nmr data have been supplemented by frozen solution 119Sn Mössbauer measurements. The evidence suggests that the dominant species in the SnF2–H2O system is a hydrated stannous fluoride, probably SnF2•H2O having Mössbauer parameters of δ = 3.46 mm s−1 and Δ = 1.70 mm s−1. When F− is added to these solutions rapid F− exchange occurs with the hydrated SnF2 and the dominant species becomes [SnF3]−. The 119Sn nmr chemical shift of [SnF3]− is ~ −700 ppm from (CH3)4Sn. The 119Sn Mössbauer parameters for frozen solutions of [SnF3]− are δ = ~ 3.1 mm s−1 Δ = 1.9 mm s−1. These spectroscopic data are cation dependent. We could find no strong evidence for high concentrations of [Sn2F5]− in any of these solutions.

Synthesis of biologically active heterocyclic compounds from allenic and acetylenic nitriles and related compounds

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Marthe Carine Djuidje Fotsing ◽  
Dieudonné Njamen ◽  
Zacharias Tanee Fomum ◽  
Derek Tantoh Ndinteh
Keyword(s):  
Michael Addition ◽  
Heterocyclic Compounds ◽  
Biological Activities ◽  
Biologically Active ◽  
Polycyclic Compounds ◽  
One Step ◽  
Pharmaceutical Properties ◽  
Related Compounds ◽  
Acetylenic Acids ◽  
The Michael Addition

Abstract Cyclic and polycyclic compounds containing moieties such as imidazole, pyrazole, isoxazole, thiazoline, oxazine, indole, benzothiazole and benzoxazole benzimidazole are prized molecules because of the various pharmaceutical properties that they display. This led Prof. Landor and co-workers to engage in the synthesis of several of them such as alkylimidazolenes, oxazolines, thiazolines, pyrimidopyrimidines, pyridylpyrazoles, benzoxazines, quinolines, pyrimidobenzimidazoles and pyrimidobenzothiazolones. This review covers the synthesis of biologically active heterocyclic compounds by the Michael addition and the double Michael addition of various amines and diamines on allenic nitriles, acetylenic nitriles, hydroxyacetylenic nitriles, acetylenic acids and acetylenic aldehydes. The heterocycles were obtained in one step reaction and in most cases, did not give side products. A brief discussion on the biological activities of some heterocycles is also provided.

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