Rotaxan‐Verbindungen, III. Synthese eines Rotaxans mit Triphenylmethyl‐Sperrgruppen und massenspektrometrische Untersuchungen

Schill, Gottfried; Zürcher, Clemens; Vetter, Walter

doi:10.1002/cber.19731060128

Cited by 24 publications

(9 citation statements)

References 10 publications

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“…Synthesis of rotaxane 115 by Schill, Zürcher, and Vetter from precursor 94 (which preceded the earlier obtained rotaxane 113 , too; see Scheme ).…”

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 92%

“…Schill et al's syntheses of the rotaxanes 113 (Scheme ) and 115 (Scheme ) followed an entirely different concept than Scheme . These workers focused on much better threading (1) by enforced proximities through intra‐ rather than intermolecularity and (2) appropriately pre‐determined orientations of the reactive moieties within the reactant.…”

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 99%

“…Rotaxane 113 of Scheme and rotaxane 115 of Scheme were gained from the identical precursor 94 by a series of common transformations. This is because these rotaxanes differed only by the end‐groups of their axle.…”

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 99%

“…The end‐groups, which cause the mechanical bonding in the rotaxane 115 , are trityl groups (Scheme ). They were introduced into the ω,ω′‐dibromide 94 by a double S N 2 reaction with trityllithium . These end‐group installments delivered the bis( ansa ‐compound) 112 (Scheme ) in 81 % yield and 114 (Scheme ) in 65 % yield …”

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 99%

“…Carrying on the bis( ansa ‐compound) 112 of Scheme to the rotaxane 113 as well as carrying on the bis( ansa ‐compound) 114 of Scheme to the rotaxane 115 would have required only 3 steps on paper. In reality, the step requirements were 4 and 5, respectively. This is because some operations were performed separately or multiply in order to optimize the overall yield.…”

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 99%

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Pioneering Work on Catenanes, Rotaxanes, and a Knotane in the University of Freiburg 1958–1988

Brückner

2019

Eur J Org Chem

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Research at the University of Freiburg is summarized which aimed at realizing catenanes, rotaxanes, and a molecular knot from 61–62 until 41 years ago. Taking a fresh view at ansa‐compounds – distinct from those in which he had been interested for other reasons before – Arthur Lüttringhaus began to tackle syntheses of catenanes in 1957. The first isolation of a pure catenane (37) succeeded in 1964 jointly with Gottfried Schill. Most of the progress made in the sequel was due to Schill alone or achieved under his direction; in addition, a few follow‐up studies were published without Schill or Lüttringhaus being their authors. The major feats of these endeavors were the syntheses of the following molecules: (1) the first catenanes (38 – de‐acetyl‐41, 74) without a ring in any constituent (this feature makes them unique till today; the catenane 74 holds the additional record of being the only all‐hydrocarbon catenane till now); the first [3]catenanes at all (obtained as a mixture of constitutional isomers C2v‐97 and C2h‐97); the first [3]catenanes exhibiting topological isomerism (89, iso‐89, and neo‐iso‐89); the rotaxanes 70 [which had the design peculiarity of being convertible into a catenane (74)], 113 (Schill's #1‐rotaxane), and 115; the pre‐knotane rac‐dia‐iso‐123 [provided it was obtained and not (only) its topological isomer dia‐iso‐123]. – For due perspectives, pertinent studies of third parties are included, too: 1) Wasserman's reports on the isolation of the catenane 8 are analyzed in great detail; the conclusion is that the identity of 8 was never established. 2) Schill's oscillating rotaxane 70 from 1988, which is subject to a reversible and non‐degenerate ring migration (→ iso‐70), is supplemented by Stoddart's much faster oscillating rotaxane 71 from 1991, which undergoes a reversible and degenerate ring migration (→ 71 instead of → iso‐71) and was dubbed “molecular shuttle”. 3) The first [3]catenanes from the groups of Schill (97; 1969), Sauvage (98 and 99; 1985), and Stoddart (100–102; 1991) are juxtaposed. 4) The Harrisons' synthesis of the rotaxane 106 by a most noteworthy solid‐phase approach (1967) is recalled in the context of Schill's synthesis of the rotaxane 113 (1967 or 1969). 5) Attempts at threading α‐cyclodextrin by long‐chain 1,ω‐dithiols (→ 130) and ring‐closing the latter oxidatively for obtaining catenated disulfides failed in Lüttringhaus' 1957/1958 studies; in contrast, Stoddart's threading permethyl‐β‐cyclodextrin (133) by the long‐chain 1,ω‐diamine 132 and ring‐closing the latter by a double condensation with terephthaloyl dichloride was successful by providing 3 % of the catenated bislactame 134 in 1993. The concluding section characterizes the synthetic strategies towards catenanes and rotaxanes developed in Freiburg as “template‐based”. This differs from the Nobel Prize Committee's assessment.

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“…Synthesis of rotaxane 115 by Schill, Zürcher, and Vetter from precursor 94 (which preceded the earlier obtained rotaxane 113 , too; see Scheme ).…”

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 92%

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 99%

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 99%

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 99%

Section: The First Rotaxanes: the Harrisons And Schill Competingmentioning

confidence: 99%

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Pioneering Work on Catenanes, Rotaxanes, and a Knotane in the University of Freiburg 1958–1988

Brückner

2019

Eur J Org Chem

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A [2]Catenane and a [2]Rotaxane as Prototypes of Topological and Euclidean Molecular “Rubber Gloves”

et al. 2001

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A [2]catenane and a [2]rotaxane have been prepared from a C2-symmetric, 2,9-diphenyl-1,10-phenanthroline-based (dpp-based) macrocycle incorporating a 1,5-dioxynaphthalene subunit by means of the transition metal templated technique. In the case of the catenane, this macrocycle is interlocked with a dpp-based macrocycle that is oriented through the location of a p-tolyl substituent in the 4-position of the phenanthroline subunit. In the case of the rotaxane, the C2-symmetric macrocycle is threaded onto an oriented, dumbbell-shaped molecule, based on the same 4-p-tolyl-1,10-phenanthroline subunit, which bears tetraarylmethane stoppers. Both species are chemically achiral molecules, yet they are composed entirely of asymmetric, mirror-image conformations. Conformational enantiomerization processes therefore take place exclusively by chiral pathways, conferring on these molecules the "rubber glove" property. However, while the molecular graph (constitutional formula) of the [2]rotaxane can be deformed into a planar and, hence, rigidly achiral representation, a feature shared by a few other compounds in the literature that have been characterized as "Euclidean rubber gloves", the molecular graph of the [2]catenane cannot be deformed in this way. It therefore has the unique property of being a chemically achiral "topological rubber glove".

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Rotaxanes: From Random to Transition Metal‐Templated Threading of Rings at the Molecular Level

Chambron¹

1999

Perspectives in Supramolecular Chemistry

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Rotaxan‐Verbindungen, III. Synthese eines Rotaxans mit Triphenylmethyl‐Sperrgruppen und massenspektrometrische Untersuchungen

Cited by 24 publications

References 10 publications

Pioneering Work on Catenanes, Rotaxanes, and a Knotane in the University of Freiburg 1958–1988

Pioneering Work on Catenanes, Rotaxanes, and a Knotane in the University of Freiburg 1958–1988

A [2]Catenane and a [2]Rotaxane as Prototypes of Topological and Euclidean Molecular “Rubber Gloves”

Rotaxanes: From Random to Transition Metal‐Templated Threading of Rings at the Molecular Level

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