Katalysierte Homologisierung von Benzol mit Diazomethan zum Cycloheptatrien

Müller, Eugen; Fricke, Horst

doi:10.1002/jlac.19636610103

Cited by 48 publications

(9 citation statements)

References 26 publications

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“…The isolation of CHT-14(7 was performed, as in ref 2, via preparative glpc; this is sample A. Half of the above photolysis reaction mixture was irradiated under the same conditions for another 4 hr to check on possible isomerization of CHT-14C after' formation; this is sample B.…”

Section: Experimental Details and Resultsmentioning

confidence: 99%

Partial degradation of 1,3,5-cycloheptatriene-14C obtained from hot-atom, photolytic, and "thermal" reactions

Pohlit¹,

Lemmon²

1971

J. Phys. Chem.

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Section: Experimental Details and Resultsmentioning

confidence: 99%

Partial degradation of 1,3,5-cycloheptatriene-14C obtained from hot-atom, photolytic, and "thermal" reactions

Pohlit¹,

Lemmon²

1971

J. Phys. Chem.

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“…[9] This sensible explanation was followed by many publications claiming the reactive species had a carbene/Cu bond. [10] Hammond, however, postulated the possibility of the intervention of a charge-transfer complex between triplet CH 2 and Cu powder or soluble Fe III tris(dipivaloylmethide). [11] He considered that the delivery of the CH 2 fragment to an olefin occurs through a triplet 1,3-biradical but, as inferred from George Porters finding of rapid quenching of anthracene phosphorescence by Fe salts, [12] its spin conversion Scheme 1.…”

Section: The Birth Of Organometallic Asymmetric Catalysismentioning

confidence: 99%

Facts are the Enemy of Truth—Reflections on Serendipitous Discovery and Unforeseen Developments in Asymmetric Catalysis

Noyori

2012

Angew Chem Int Ed

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As Louis Pasteur said, "Chance favors only a prepared mind." Serendipitous events reorienting the pathway of science often occur through the actions of dedicated individuals with unique cultural and educational backgrounds, an original sense of values, and firm principles. Science is the fountainhead of human knowledge and possesses an indispensable cultural value. Science-based technologies and the innovations derived from them are the foundation of the civilized society in which we live today. All scientific endeavors begin with observations, or facts. However, the real goal of research activity is to convert accumulated knowledge to something with new technological, economic, or social value. Innovation is an essential aspect to assure the continued survival of humanity. And often, as my half-century of research reflects, the act of turning facts into values is facilitated by dialogue. Thus, to acquire the necessary combined wisdom, scientists must have ongoing conversations with the societies they serve, as well as with their counterparts in other nations.

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“…In order to determine the effect of substituents in 1,3,5-cycloheptatriene on the proton chemical shifts, we have synthesized the unsubstituted 1,3,5-cycloheptatriene [8]. The IH NMR spectrum of this compound displays signals of four types" (I) A triplet due to protons in position 7 with 5 = 2.25 ppm (J7-6 = J7-I -~ 6 -7 Hz).…”

mentioning

confidence: 99%

Synthesis of some 1,3,5-cycloheptatriene derivatives from tropylium hexachlorophosphate chloride

et al. 1997

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The cycloheptatriene fragment enters into various biologically active compounds, in particular, efficient antimitotic agents [ 1,2] used in the chemotherapy of malignant tu-In this connection, development of new methods for the synthesis of compounds belonging to the class ofcycloheptatrienes is of current interest.A key role in the synthesis of 1,3,5-eycloheptatriene derivatives belongs to tropylium salts (bromide, perchlorate, tetrafluoroborate) which are typically obtained by involved multistage processes. From the practical standpoint, the double salt of tropylium hexachlorophosphate chloride [4] is more available. As will be shown below, this substance can be successfully used for the synthesis of a number of substituted cycloheptauienes by the following scheme: ported earlier [5] for the interaction of malonodinitrile with tropylium bromide. The synthesized compounds appear for the most part as transparent mobile liquids with a sharply irritating odor. The proposed structures were confirmed by the results ofphysicochemical analyses. In particular, the IH NMR spectrum of compound IIa contains a singlet due to protons of the methoxy group at 8 = 6.36 ppm. Protons of the seven-membered cycle are manifested as four groups of signals with chemical shifts ~ = 6.36, 5.70, 5.13, and 2.97 ppm. The spectrum is generally similar to that reported for a compound obtained by the interaction oftropylium perchlorate with methanol [6].Interaction of compound IIa with phosphorus pentachloride leads to compound I in quantitative yield. The proposed structure was confirmed by conversion of the product into tropylium tetrafluoroborate using the method described in [7]: 494The physicochemical properties of the synthesized compounds II -VII are presented in Table I.In order to determine the effect of substituents in 1,3,5-cycloheptatriene on the proton chemical shifts, we have synthesized the unsubstituted 1,3,5-cycloheptatriene [8]. The IH NMR spectrum of this compound displays signals of four types" (I) A triplet due to protons in position 7 with 5 = 2.25 ppm (J7-6 = J7-I -~ 6 -7 Hz).(2) A multiplet due to protons in positions 1 and 6 with 5 = 5.35 ppm (J1 -z = J5-6 ~ 10 Hz; JT-1 = J7-6 = 6 -7 Hz).(3) A multiplet due to protons in positions 2 and 5 with 5 = 6.20 ppm. This multiplet allows us to readily determine the spin-spin coupling constants (JI -z = Js-6 ~ 10 Hz).

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Katalysierte Homologisierung von Benzol mit Diazomethan zum Cycloheptatrien

Cited by 48 publications

References 26 publications

Partial degradation of 1,3,5-cycloheptatriene-14C obtained from hot-atom, photolytic, and "thermal" reactions

Partial degradation of 1,3,5-cycloheptatriene-14C obtained from hot-atom, photolytic, and "thermal" reactions

Facts are the Enemy of Truth—Reflections on Serendipitous Discovery and Unforeseen Developments in Asymmetric Catalysis

Synthesis of some 1,3,5-cycloheptatriene derivatives from tropylium hexachlorophosphate chloride

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