The chemistry of 6-dialkylamino-2H-1,3-oxazin-2-ones. Reversible thermal ring-opening and cycloaddition reactions with N-arylmaleimides and 1-diethylaminopropyne. X-Ray crystal structures of a 5H-2-pyridone and a 1H-2-pyridone

1981 ◽  
pp. 2878 ◽  
Author(s):  
Ahmet E. Baydar ◽  
Gerhard V. Boyd ◽  
Peter F. Lindley ◽  
Frank Watson ◽  
Paul W. Manley ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Ring Opening ◽  
Cycloaddition Reactions ◽  
X Ray

Formation of L‐Threonic Acid from L‐Ascorbic Acid Oxidative Ring Opening and its Coordination to PtII: X‐ray Crystal Structures of [Pt(threonato‐O,O′)(PPh3)2] and [Pt(oxalato)(PPh3)2]

2008 ◽  
Vol 2008 (19) ◽  
pp. 3056-3061 ◽  
Author(s):  
Paola Bergamini ◽  
Elena Marchesi ◽  
Andrea Marchi ◽  
Valerio Bertolasi ◽  
Marco Fogagnolo ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Crystal Structures ◽  
Ring Opening ◽  
X Ray ◽  
Threonic Acid

Synthesis, structure, and properties of the hexagermane Pri3Ge(GePh2)4GePri3

2014 ◽  
Vol 92 (6) ◽  
pp. 533-541 ◽  
Author(s):  
Kimberly D. Roewe ◽  
James A. Golen ◽  
Arnold L. Rheingold ◽  
Charles S. Weinert
Keyword(s):  
Physical Properties ◽  
Crystal Structures ◽  
Ring Opening ◽  
Polarized Light ◽  
Structure And Properties ◽  
Opposite Orientation ◽  
X Ray ◽  
Pale Yellow ◽  
Deep Blue ◽  
Irreversible Oxidation

The synthesis of the hexagermane Pri3Ge(GePh2)4GePri3 was achieved starting from the cyclotetragermane (Ph2Ge)4. Ring-opening of (Ph2Ge)4 with Br2 yielded Br(GePh2)4Br that was converted to H(GePh2)4H, and this material was treated with two equiv. of Pri3GeNMe2 to furnish Pri3Ge(GePh2)4GePri3 via the hydrogermolysis reaction. The X-ray crystal structures of (Ph2Ge)4, Br(GePh2)4Br and Pri3Ge(GePh2)4GePri3 were determined. The hexagermane Pri3Ge(GePh2)4GePri3 represents the longest structurally characterized linear oligogermane reported to date and exhibits physical properties that resemble those of the larger polygermane systems. The hexagermane is luminescent and interacts with polarized light, appearing pale yellow under one orientation of polarized light and deep blue under the opposite orientation. The electrochemistry of Pri3Ge(GePh2)4GePri3 was also explored, and this species exhibits the expected five irreversible oxidation waves.

scholarly journals Synthesis and crystal structures of multifunctional tosylates as basis for star-shaped poly(2-ethyl-2-oxazoline)s

2010 ◽  
Vol 6 ◽  
pp. 773-783 ◽  
Author(s):  
Richard Hoogenboom ◽  
Martin W M Fijten ◽  
Guido Kickelbick ◽  
Ulrich S Schubert
Keyword(s):  
Crystal Structures ◽  
Ring Opening ◽  
Functional Materials ◽  
Diode Array ◽  
X Ray ◽  
H Nmr ◽  
Tosyl Chloride ◽  
Array Detectors ◽  
Polymer Architectures ◽  
Cationic Ring Opening Polymerization

The synthesis of well-defined polymer architectures is of major importance for the development of complex functional materials. In this contribution, we discuss the synthesis of a range of multifunctional star-shaped tosylates as potential initiators for the living cationic ring-opening polymerization (CROP) of 2-oxazolines resulting in star-shaped polymers. The synthesis of the tosylates was performed by esterification of the corresponding alcohols with tosyl chloride. Recrystallization of these tosylate compounds afforded single crystals, and the X-ray crystal structures of di-, tetra- and hexa-tosylates are reported. The use of tetra- and hexa-tosylates, based on (di)pentaerythritol as initiators for the CROP of 2-ethyl-2-oxazoline, resulted in very slow initiation and ill-defined polymers, which is most likely caused by steric hindrance in these initiators. As a consequence, a porphyrin-cored tetra-tosylate initiator was prepared, which yielded a well-defined star-shaped poly(2-ethyl-2-oxazoline) by CROP as demonstrated by SEC with RI, UV and diode-array detectors, as well as by 1H NMR spectroscopy.

1,3-Dipolar cycloaddition reactions of monocyclic aziridines with dimethyl 1-cyclobutene-1,2-dicarboxylate

1994 ◽  
Vol 72 (10) ◽  
pp. 2108-2117 ◽  
Author(s):  
Kiyoshi Matsumoto ◽  
Hirokazu Iida ◽  
Takane Uchida ◽  
Yoshimi Yabe ◽  
Akikazu Kakehi ◽  
...  
Keyword(s):  
Ring Opening ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Thermally Induced ◽  
X Ray ◽  
Orbital Interactions ◽  
Dipole Interactions

The thermally induced [2 + 3] cycloadditions of certain monocyclic aziridines to dimethyl 1-cyclobutene-1,2-dicarboxylate are described. The structures of the resulting bicyclic adducts were established unambiguously by X-ray analyses. The stereochemistries of the [2 + 3] adducts were interpreted in terms of dipole–dipole interactions and secondary orbital interactions. In certain cases an initial thermal conrotatory ring opening of the cyclobutene to 2,3-di(methoxycarbonyl)-1,3-butadiene precedes the [2 + 3] cycloaddition, affording the unexpected pyrrolidine adducts 12a and 12b. The structures and stereochemistries of the latter established by X-ray analysis strongly suggest that secondary orbital interactions between the phenyl and ester groups control and stereochemistry of the reactions.

Ring opening complexation of nickel(II) and copper(II) by 2-phenyl-2-(2-pyridyl)imidazolidine: Synthesis, spectra and X-ray crystal structures

Polyhedron ◽  
2008 ◽  
Vol 27 (11) ◽  
pp. 2379-2385 ◽  
Author(s):  
Sanaa M. Emam ◽  
Patrick McArdle ◽  
James McManus ◽  
Mary Mahon
Keyword(s):  
Crystal Structures ◽  
Ring Opening ◽  
X Ray
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