Chiral Sulfur Compounds. XV. Diastereoselective Additions of Lithiated S-Benzyl-N-t-butyldiphenylsilyl-S-methyl-sulfoximine to Imines and Aldehydes

1992 ◽  
Vol 45 (5) ◽  
pp. 807 ◽  
Author(s):  
SG Pyne ◽  
B Dikic ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Transition State ◽  
Single Crystal ◽  
Structure Analysis ◽  
Boron Trifluoride ◽  
Lithium Salt ◽  
Sulfur Compounds ◽  
X Ray ◽  
Boron Trifluoride Diethyl Etherate

The lithium salt of racemic S-benzyl-N-t- butyldiphenylsilyl-S-methylsulfoximine (2) undergoes 1,2-addition to imines that have been activated by precomplexation with boron trifluoride diethyl etherate (BF3.Et2O), and aldehydes , with high diastereoselectivity. The relative lS*,2S.*,S*s stereochemistry of the major diastereomeric adducts of (2) and EtCH = NPh and PriCH = NPh , and the relative lS *,2S*,S*s stereochemistry of the major diastereomeric adduct of (2) and propanal were unequivocally determined by single-crystal X-ray structure analysis. An open transition state has been proposed to account for the stereochemical outcome of these reactions.

scholarly journals Deca(4-methylbenzyl)ferrocen und -stannocen / Deca(4-methylbenzyl)ferrocene and -stannocene

2005 ◽  
Vol 60 (5) ◽  
pp. 527-532 ◽  
Author(s):  
Herbert Schumann ◽  
Klaudia Sühring ◽  
Roman Weimann ◽  
Markus Hummert
Keyword(s):  
Single Crystal ◽  
Structure Analysis ◽  
Mass Spectra ◽  
Lithium Salt ◽  
Butyl Lithium ◽  
X Ray ◽  
New Compounds ◽  
C Nmr

Cyclopentadiene reacts with five equivalents of 4-methylbenzylalcohol (1:5,6 mole ratio) and sodium yielding penta(4-methylbenzyl)cyclopenta-2,4-diene (1), which upon treatment with butyl lithium affords the lithium salt [(4-MeC6H4CH2)5C5]Li (2). The reactions of 2 with FeCl2 and SnCl2 result in the formation of deca(4-methylbenzyl)ferrocene (3) and deca(4-methylbenzyl)stannocene (4), respectively. The 1H and 13C NMR, IR and mass spectra of the new compounds as well as the single crystal X-ray structure analysis of 1 are reported and discussed.

How the Magnetic Field Impacts the Chiroptical Activities of Helical Copper Enantiomers

2021 ◽  
Author(s):  
jialu wu ◽  
Bo Li ◽  
Hong Wang ◽  
Ying Zhen Lai ◽  
Yue Ye ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solid State ◽  
Thermogravimetric Analysis ◽  
Single Crystal ◽  
Structure Analysis ◽  
Chiral Ligands ◽  
X Ray ◽  
The Magnetic Field

A pair of enantiomers {[Cu(L-pro)(L-tyr)]·2H2O}n (L-1) and {[Cu(D-pro)(D-tyr)]·2H2O}n (D-1) based on the chiral ligands L/D-proline and L/D-tyrosine were synthesized and investigated by single-crystal X-ray structure analysis, IR, thermogravimetric analysis, solid-state...

scholarly journals Arene Ruthenium Metalla-Assemblies with Anthracene Moieties for PDT Applications

Inorganics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 97 ◽  
Author(s):  
Marie Gaschard ◽  
Farzaneh Nehzat ◽  
Thomas Cheminel ◽  
Bruno Therrien
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
General Formula ◽  
Structure Analysis ◽  
White Light ◽  
Light Irradiation ◽  
Synthesis And Characterization ◽  
X Ray

The synthesis and characterization of three metalla-rectangles of the general formula [Ru4(η6-p-cymene)4(μ4-clip)2(μ2-Lanthr)2][CF3SO3]4 (Lanthr: 9,10-bis(3,3’-ethynylpyridyl) anthracene; clip = oxa: oxalato; dobq: 2,5-dioxido-1,4-benzoquinonato; donq: 5,8-dioxido-1,4-naphthoquinonato) are presented. The molecular structure of the metalla-rectangle [Ru4(η6-p-cymene)4(μ4-oxa)2(μ2-Lanthr)2]4+ has been confirmed by the single-crystal X-ray structure analysis of [Ru4(η6-p-cymene)4(μ4-oxa)2(μ2-Lanthr)2][CF3SO3]4 · 4 acetone (A2 · 4 acetone), thus showing the anthracene moieties to be available for reaction with oxygen. While the formation of the endoperoxide form of Lanthr was observed in solution upon white light irradiation, the same reaction does not occur when Lanthr is part of the metalla-assemblies.

scholarly journals New Spiro-Tin Compounds: Reaction of N,N′-Dialkyl Sulfur Diimides with Cyclic Bis(amino)stannylenes - Unexpected Formation of a N-N Bond

1995 ◽  
Vol 50 (12) ◽  
pp. 1811-1817 ◽  
Author(s):  
Max Herberhold ◽  
Christian Köhler ◽  
Wolfgang Milius ◽  
Bernd Wrackmeyer
Keyword(s):  
Molecular Structure ◽  
Magnetic Resonance ◽  
Single Crystal ◽  
Structure Analysis ◽  
Membered Ring ◽  
Monoclinic Space Group ◽  
Unexpected Formation ◽  
Tin Compounds ◽  
X Ray ◽  
Tert Butyl

N,N′-Dialkyl sulfur diimides (1), R(NSN)R [R = Me (a), Et (b), nPr (c), nBu (d)] react with cyclic bis(amino)stannylenes such as 1,3-di-tert-butyl-4,4-dimethyl-1,3,4,2λ2-diazasilastannetedine (2) or 1,3-di-tert-butyl-4,4,5,5-tetramethyl-1,3,4,5,2λ2-diazadisilastannolidine (3) in a 2:1 ratio to give the new spiro-tin(IV) compounds 5a-d, 6b and 6c, built from the respective cyclic bis(amino)stannylene and a seven-membered ring in which the two sulfur diimide groups are coupled via a N-N bond and across the tin atom. A 1:1 adduct 4 is proposed as an intermediate which is the final product 4e in the case of R = tBu (1e). The products were characterized by multinuclear magnetic resonance (1H, 13C, 15N, 29Si, 119Sn NMR), and in the case of 5c the molecular structure was determined by single crystal X-ray structure analysis [monoclinic, space group C2/c ; a = 1504.1(3), b = 1393.3(3), c = 1688.6(3) pm; β = 115.71(3)°].

Die absolute Konfiguration der Juglomycine/The Absolute Configuration of the Juglomycins

1989 ◽  
Vol 44 (3) ◽  
pp. 345-352 ◽  
Author(s):  
Johann Krupa ◽  
Helmut Lackner ◽  
Peter G. Jones ◽  
Karen Schmidt-Bäse ◽  
George M. Sheldrick
Keyword(s):  
Single Crystal ◽  
Structure Analysis ◽  
Absolute Configuration ◽  
X Ray ◽  
The Absolute ◽  
Dibromo Derivative

The absolute configurations of the known juglomycins A (1) and B (2) have been elucidated by single crystal X-ray structure analysis of 1 and its 6,8-dibromo derivative (1b). The structure of 2 has been corrected; it differs from 1 in its configuration at C-4', and not at C-3' as previously assumed. Relationships with the closely related isochromanquinone antibiotics are discussed.

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