A simple route to optically pure 2,3-diaminobutane

Chooi, Simon Y.M.; Leung, Pak‐Hing; Ng, S. C. Cindy; Quek, Glenn; Sim, Keng‐Yeow

doi:10.1016/s0957-4166(00)86141-8

Cited by 14 publications

(6 citation statements)

References 13 publications

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“…Synthesis of complexes 12 and 13 is described in Scheme . Starting diamines 6 and 7 were prepared according to a published procedure and subsequently coupled to o -tolyl groups by Pd-catalyzed reaction to give diamines 8 and 9 . Dihydroimidazolium salts 10 and 11 were obtained by salification of 8 and 9 with HCl, followed by condensation with triethyl orthoformate.…”

Section: Resultsmentioning

confidence: 99%

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Influence of syn and anti Configurations of NHC Backbone on Ru-Catalyzed Olefin Metathesis

et al. 2009

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The synthesis and characterization of two ruthenium-based olefin metathesis catalysts bearing N-heterocyclic carbene (NHC) ligands with syn (12) and anti (13) methyl groups on the backbone and o-tolyl N-substituents are reported. The catalytic performance of both 12 and 13 has been evaluated in ring-closing metathesis, ring-opening metathesis polymerization, and cross-metathesis reactions. The results have been compared to those obtained in the presence of the Grubbs second-generation catalyst 3a, lacking substituents on the NHC backbone. Of particular interest, compound 12 outperformed both 3a and 13 in the ring-closing metathesis of hindered olefins, demonstrating to be the most active monophosphine catalyst in this class of metathesis reactions up to now. The influence of syn and anti stereochemical relationship of methyl groups on the NHC backbone of 12 and 13 in the formation of sterically encumbered olefins has been discussed. The X-ray structure of novel ruthenium complex 15, generated during an attempt to prepare pyridine-based complex 14 and identified as a decomposition product derived from C−H activation of N-tolyl substituents, is also reported.

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Section: Resultsmentioning

confidence: 99%

“…These products were used without further purification. Diamines 6 and 7 , as well as dienes 18 and 20 , were synthesized according to literature procedures.…”

Section: Methodsmentioning

confidence: 99%

Influence of syn and anti Configurations of NHC Backbone on Ru-Catalyzed Olefin Metathesis

et al. 2009

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“…1), (+)-(7S,9S)-9-acetyl-9-amino-7-[(2-deoxy-β-D-erythro-pentopyranosyl)oxy]-7,8,9,10-tetrahydro-6,11-dihydroxy-5,12-naphthacenedione hydrochloride (SM-5887), amrubicinol hydrochloride and ICRF-193 were prepared by Sumitomo Pharmaceuticals Co., Ltd. (Osaka). 12,13) 14) Aliquots (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) µl) of DNA solution (0.2 mg/ml), up to 150 µl, were added to a cuvette filled with 3 ml of reaction buffer. The reaction mixture was stirred for 5 min, and the absorbance was measured on a spectrometer V-520-SR (Nihon Bunkoh, Tokyo) at 460 nm for amrubicin and amrubicinol, and 470 nm for DXR.…”

Section: Methodsmentioning

confidence: 99%

A New Antitumor Agent Amrubicin Induces Cell Growth Inhibition by Stabilizing Topoisomerase II‐DNA Complex

Hanada¹,

Mizuno²,

Fukushima³

et al. 1998

Japanese Journal of Cancer Research

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Amrubicin is a novel, completely synthetic 9-aminoanthracycline derivative. Amrubicin and its C-13 alcohol metabolite, amrubicinol, inhibited purified human DNA topoisomerase II (topo II). Compared with doxorubicin (DXR), amrubicin and amrubicinol induced extensive DNA-protein complex formation and double-strand DNA breaks in CCRF-CEM cells and KU-2 cells. In this study, we found that ICRF-193, a topo II catalytic inhibitor, antagonized both DNA-protein complex formation and double-strand DNA breaks induced by amrubicin and amrubicinol. Coordinately, cell growth inhibition induced by amrubicin and amrubicinol, but not that induced by DXR, was antagonized by ICRF-193. Taken together, these findings indicate that the cell growthinhibitory effects of amrubicin and amrubicinol are due to DNA-protein complex formation followed by double-strand DNA breaks, which are mediated by topo II.Key words: Amrubicin -Anthracycline -DNA-protein complex -Double-strand DNA break -DNA topoisomerase II DNA topoisomerase II (topo II) is a nuclear enzyme that regulates DNA topology through strand breakage, strand passage and religation. Thus, topo II is extensively involved in DNA metabolism, including replication, transcription, recombination and sister chromatid segregation.1) Mammalian topo II is the primary cellular target of a number of potent antitumor agents such as doxorubicin (DXR), daunorubicin (DNR), etoposide and amsacrine (m-AMSA).2) These agents interfere with the breakagereunion reaction of topo II by trapping a covalent enzyme-DNA complex, termed "cleavable complex," in which DNA strands are broken and their 5′ termini are covalently linked to the protein. In general, the cytotoxicity of these topo II poisons is dependent on stabilization of the cleavable complex followed by topo II-mediated DNA damage, rather than inactivation of topo II cellular functions. 3)Amrubicin is a novel, completely synthetic 9-aminoanthracycline derivative, and has antitumor activities in murine experimental tumor systems and human tumornude mouse systems. 4,5) Like other anthracycline derivatives, such as DXR and DNR, amrubicin is converted to its C-13 alcohol metabolite, amrubicinol.6) In contrast to doxorubicinol and daunorubicinol, amrubicinol has much higher antitumor activity than the parent drug in vitro. 6, 7)In addition, amrubicin showed much weaker cardiotoxicity than DXR in a rabbit chronic experimental model. 8)Phase II clinical trials of amrubicin for the treatment of malignant lymphoma, superficial bladder, small cell lung carcinoma, and non-small cell lung carcinoma are in progress. 9,10) Amrubicin showed substantial activity (response rate of 25%) against non-small cell lung cancer, and a response rate of 78.8% was obtained against small cell lung cancer.The mechanisms underlying the antitumor activities of amrubicin and amrubicinol are not well understood. Our present study has shown that amrubicin and amrubicinol target human topo II by stabilizing the cleavable complex. Furthermore, amrubicin and amrubicinol induced DNApro...

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“…Moreover, the often concomitant formation of the meso diastereomer with most methods further compromises the yield of the desired product in addition to the requirement of a tedious purification procedure. Syntheses from chiral building blocks or auxiliaries provide improved yields but require additional synthetic steps at the expense of valuable chiral starting materials (Figure b). , The efficient synthesis of chiral vicinal diamines with excellent yields, selectivities, and practicality remains a significant challenge. We herein report a general, simple, and practical method for the synthesis of a wide range of chiral vicinal diamines by developing a chiral diboron-templated reductive coupling of imines.…”

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confidence: 99%

Enantioselective Reductive Coupling of Imines Templated by Chiral Diboron

Zhou

Chen

et al. 2020

J. Am. Chem. Soc.

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We herein report a general, practical, and highly efficient method for asymmetric synthesis of a wide range of chiral vicinal diamines via reductive coupling of imines templated by chiral diboron. The protocol features high enantioselectivity and stereospecificity, mild reaction conditions, simple operating procedures, use of readily available starting materials, and a broad substrate scope. The method signifies the generality of diboron-enabled [3,3]-sigmatropic rearrangement.

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A simple route to optically pure 2,3-diaminobutane

Cited by 14 publications

References 13 publications

Influence of syn and anti Configurations of NHC Backbone on Ru-Catalyzed Olefin Metathesis

Influence of syn and anti Configurations of NHC Backbone on Ru-Catalyzed Olefin Metathesis

A New Antitumor Agent Amrubicin Induces Cell Growth Inhibition by Stabilizing Topoisomerase II‐DNA Complex

Enantioselective Reductive Coupling of Imines Templated by Chiral Diboron

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