Etude comparative de la structure d'oxa- et thia-cyclostannanes

Delmas, M.; Maire, J. C.; McFarlane, William; Richard, Y.

doi:10.1016/s0022-328x(00)88140-1

Cited by 11 publications

(3 citation statements)

References 7 publications

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“…In contrast to this the dithiastannolanes appear as monomers (Smith, White and Smith, 1972;Delmas et al, 1975;Mathiasch, 1976;Rodens and Taddei, 1985;Davies and Slater, 1986;Bates et al, 1987, Davies et al, 1988. In non-coordinating solvents these dialkyl dioxastannolanes and oxathiastannolanes occur as oligomers, mainly as dimers, as many different investigations confirm.…”

Section: Introductionmentioning

confidence: 86%

The crystal and molecular structure of 2,2-diphenyl-1,3,2-oxathiastannolane

Engel¹

1992

Zeitschrift Für Kristallographie - Crystalline Materials

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The crystal structure of 2,2-diphenyl-l,3,2-oxathiastannolane, (C6H5)2Sn(OCH^CH^), has been determined by means of X-ray diffraction. The space group is Pljc, Af, = 349.04, a = 8.807(4) Ä, b = 13.867(4) Ä, c = 11.645(5) A,ß = 104.73(3)°, V = 1375.43 Ä^, Z = 4, /), = 1.685 gcm-^ A(Mo^a) = 0.71069 Ä, /i = 19.91 cm"', F(000) = 687.93, r = 213(5) K. The least-squares refmement was based on 4224 independent reflections with I> 3 cr(/) and /?-factors in the last refinement were R = 0.0279 and wR = 0.0295. Two molecules of the formula unit are dimerized by a Sn-O' and a Sn'-O bond. Because of the dimerization the coordination number of tin becomes 5. The strongly distorted coordination polyhedron of tin can be described as intermediate between a trigonal bipyramid, with S and O' on the axial positions and a Square pyramid, with the atom C(l) of the first phenyl ring at the apex. The distortion seems to be due to the constraints, which are imposed by the tricyclic ring system of the dimeric molecule.' Present address:

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Section: Introductionmentioning

confidence: 86%

The crystal and molecular structure of 2,2-diphenyl-1,3,2-oxathiastannolane

Engel¹

1992

Zeitschrift Für Kristallographie - Crystalline Materials

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“…In agreement with the well-known fact that Sn−S bonds are more stable than Sn−O bonds, it was found that thiolactones insert quantitatively into the Sn−O bonds of the Sn containing macrocycles (eq 2). , On this basis it was anticipated that cyclic esters of 1,2-dimercaptoethane ( 3 ) (or 1,3-dimercaptopropane) will also insert into Sn−O bonds (eq 3). However, in this case the insertion product ( 4 ) should be unstable and undergo an intramolecular ring contraction (eq 4) with the concomitant elimination of 2-stanna 1,3-diolane ( 5 ) (or 2-stanna-1,3-dithiane) which is a stable and well documented compound . This reaction sequence should give cyclic poly(ether ester)s ( 6 ) in high yields without intermediate ring cleavage and without any need of the Ruggli−Ziegler dilution principle.…”

Section: Introductionmentioning

confidence: 99%

“…However, in this case the insertion product (4) should be unstable and undergo an intramolecular ring contraction (eq 4) with the concomitant elimination of 2-stanna 1,3-diolane (5) (or 2-stanna-1,3-dithiane) which is a stable and well docu- mented compound. 10 This reaction sequence should give cyclic poly(ether ester)s ( 6) in high yields without intermediate ring cleavage and without any need of the Ruggli-Ziegler dilution principle. The present work had the purpose to explore the usefulness of this novel approach on the basis of the cyclic dithiophthalates 7a and 7b.…”

Section: Introductionmentioning

confidence: 99%

Macrocycles. 20. Cyclic Poly(ethylene glycol) Phthalates via Ring-Exchange Substitution

2002

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Various oligo- and poly(ethylene glycol)s were transformed into tin-containing macrocycles by “polycondensation” with dibutyltin dimethoxide. These cyclic oligo- and poly(ethylene glycol)s were heated with a spirocycle derived from phthaloyl chloride and 1,2-dimercaptoethane. This spirocycle inserts into the Sn−O bonds with subsequent elimination of 2,2-dibutyl-2-stanna-1,3-dithiolane. By this ring-insertion/ring elimination mechanism, the Bu2Sn group in the cyclic polyethers was replaced by the phthalate unit without intermediate ring-opening. The cyclic poly(ethylene glycol) phthalates were characterized by elemental analyses by viscosity and DSC measurements, by 1H NMR, 13C NMR, and IR spectroscopy, and by MALDI−TOF mass spectrometry. Analogous experiments were conducted with a spirocycle derived from 4,5-dichlorophthalic acid which turned out to be less reactive than the unsubstituted phthalide. In summary, this new approach allows syntheses of cyclic polyether phthalates in high yields, in an “one-pot procedure” and without need of dilution.

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