Synthesis, stereochemistry, mechanisms of formation, and X-ray crystal structures of enantiomerically pure π-allylpalladium compounds formed via palladium-promoted ring opening of bicyclic alkenes

1987 ◽  
pp. 834-836 ◽  
Author(s):  
Richard C. Larock ◽  
Hanchul Song ◽  
Sangsoo Kim ◽  
Robert A. Jacobson
Keyword(s):  
Crystal Structures ◽  
Ring Opening ◽  
Enantiomerically Pure ◽  
X Ray ◽  
Mechanisms Of Formation

Synthese und Aggregatbildung eines 5-Hydroxy-2,5-dihydropyrrols. Enantiomerenreine, eindimensionale Stränge durch Wasserstoffbrückenbindungen und chiroselektive Selbstorganisation/Synthesis and Aggregation of a 5-H ydroxy-2,5-dihydropyrrole. Enantiomerically Pure, One-dimensional Strands via Hydrogen Bonds and Chiroselective Self Organization

1999 ◽  
Vol 54 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Jochen Nachtrab ◽  
Stephan Reck
Keyword(s):  
Hydrogen Bonds ◽  
Ring Opening ◽  
Self Organization ◽  
Nucleophilic Attack ◽  
X Ray Diffraction ◽  
Enantiomerically Pure ◽  
One Dimensional ◽  
X Ray ◽  
Self Selection ◽  
The One

Reaction of dimethyl 1,3-acetonedicarboxylate 8 with oxalylchloride 2 and magnesium chloride as catalyst yielded 2,3-dioxo-2,3-dihydrofuran 9, which is in equilibrium with tautomer 10 (9:10 = 1:2). Addition of thionyl chloride to a mixture of 9/10 afforded 3-chloro-2(5H)-furanone 11. The structure of 11 was unequivocally established by X-ray diffraction, which indirectly proved the structure of 10 as well. Ring opening of 11 by nucleophilic attack with benzylamine 14 in C2-position and subsequent recyclization led to racemic 3-chloro-5-hydroxy-2-oxo-2,5-dihydropyrrole 15. According to a single crystal X-ray analysis, 15 aggregates via stereospecific self selection through hydrogen bonds to give chiroselectively the one-dimensional strands ∞1[(S)-15] and ∞1[( R)-15]

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 of Racemic and Enantiomerically Pure (R*,R*,R*)-Tris(α-methylbenzyl)phosphane− X-ray Crystal Structures of the Phosphane Oxides and Borane Complexes

2003 ◽  
Vol 2003 (21) ◽  
pp. 4216-4226 ◽  
Author(s):  
Paul Wyatt ◽  
Helen Eley ◽  
Jonathan Charmant ◽  
Berian J. Daniel ◽  
Anob Kantacha
Keyword(s):  
Crystal Structures ◽  
Enantiomerically Pure ◽  
X Ray

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.

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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