72486-93-2Relevant academic research and scientific papers
Stepwise bond formation in photochemical and thermal Diels-Alder reactions of C60 with Danishefsky's dienes
Mikami, Koichi,Matsumoto, Shoji,Okubo, Yasutaka,Fujitsuka, Mamoru,Ito, Osamu,Suenobu, Tomoyoshi,Fukuzumi, Shunichi
, p. 2236 - 2243 (2000)
Mechanisms of both the photochemical and thermal Diels-Alder reactions of C60 with Danishefsky's dienes are studied on the basis of product stereochemistry, kinetics, and the detection of radical intermediates. A stereochemically defined (1E,3Z)-1-methoxy-2-methyl-3-[(trimethylsilyl)oxy]-penta-1,3-diene (1a) is used as a stereochemical probe in the Diels-Alder reactions with C60. The major Diels-Alder product is trans-adduct (3) rather than cis-adduct (4) in both the photochemical and thermal Diels-Alder reactions. Such stereochemistry indicates that the Diels-Alder reactions proceed by a stepwise mechanism rather than a concerted mechanism. The transient spectra of C60?- formed in photoinduced electron transfer from 1a to the triplet excited state of C60 (3C60*) have been detected successfully in laser flash photolysis of the 1a-C60 system. The observed rate constants determined from the dependence of the quantum yields on the concentrations of Danishefsky's dienes agree well with those for the photoinduced electron transfer from Danishefsky's dienes to 3C60*. Such an agreement together with the formation of trans-adduct (3) indicates that the photochemical Diels-Alder reaction proceeds via stepwise bond formation in the radical ion pair produced in the photoinduced electron transfer from Danishefsky's dienes to 3C60*. On the other hand, the rate constants for the thermal Diels-Alder reactions of Danishefsky's dienes are 1016 times larger than those expected for outer-sphere electron transfer from Danishefsky's dienes to C60. Thus, a strongly unsymmetrical orbital interaction is required for the thermal Diels-Alder reaction to yield trans-adduct (3) which would not be produced by a concerted pathway.
MIGRASTATIN ANALOGS IN THE TREATMENT OF CANCER
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Page/Page column 166-167, (2008/06/13)
In one aspect, the present invention provides a method for treating colon and/or ovarian cancer in a subject comprising administering to a subject in need thereof a compound of general formula (I): wherein R1-R6, R, ,-R,, Q, Y1, Y2 and n are as defined herein, wherein the compound is present in an amount effective to inhibit colon and/or ovarian tumor metastasis.
MIGRASTATIN ANALOG COMPOSITIONS AND USES THEREOF
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Page 171-172, (2010/02/08)
In one aspect, the present invention provides pharmaceutical compositions comprising a therapeutically effective amount of a compound of general formula (I), wherein R1-R6, Ra-RC, Q, Y1, Y2 and n are as defined herein, whereby the composition is formulated for administration to a subject at a dosage between about 0.1 mg/kg to about 50 mg/kg of body weight. In another aspect, the present invention provides a method for treating breast tumor metastasis in a subject comprising administering to a subject in need thereof a therapeutically effective amount of the inventive composition described directly above and a pharmaceutically acceptable carrier, adjuvant or vehicle.
The migrastatin family: Discovery of potent cell migration inhibitors by chemical synthesis
Gaul, Christoph,Njardarson, Jon T.,Shan, Dandan,Dorn, David C.,Wu, Kai-Da,Tong, William P.,Huang, Xin-Yun,Moore, Malcolm A. S.,Danishefsky, Samuel J.
, p. 11326 - 11337 (2007/10/03)
The first asymmetric total synthesis of (+)-migrastatin (1), a macrolide natural product with antimetastatic properties, has been accomplished. Our concise and flexible approach utilized a Lewis acid-catalyzed diene aldehyde condensation (LACDAC) to install the three contiguous stereocenters and the trisubstituted (Z)-alkene of migrastatin (2 + 3 → 21). Construction of the two remaining stereocenters and incorporation of the glutarimide-containing side chain was achieved by an anti-selective aldol addition of propionyl oxazolidinone 28 to angelic aldehyde 27, followed by a Horner-Wadsworth-Emmons (HWE) coupling of 32 with glutarimide aldehyde 5. Finally, the assembly of the macrocycle was realized by a highly (E)-selective ring-closing metathesis (35 → 37). Utilizing the power of diverted total synthesis (DTS), a series of otherwise inaccessible analogues was prepared and evaluated for their potential as tumor cell migration inhibitors in several in vitro assays. These studies revealed a dramatic increase in activity when the natural motif was considerably simplified, presenting macrolactones 45 and 48, as well as macrolactam 55, macroketone 60, and CF3-alcohol 71 as promising anti-metastatic agents.
