1069-54-1Relevant articles and documents
An Enantioconvergent and Concise Synthesis of Lasonolide A
Yang, Lin,Lin, Zuming,Shao, Shunjie,Zhao, Qian,Hong, Ran
, p. 16200 - 16204 (2018)
Efficient access to medicinally significant natural products is an essential basis for the development of pharmaceuticals. The limited availability of marine natural products impedes broad biological evaluation. Despite several elegant syntheses of (?)-lasonolide A having been reported, a practical synthesis of this potent anticancer polyketide remains elusive. Based on the application of borane as a traceless protecting group and the development of an unprecedented bissulfone reagent for Julia olefination, (?)-lasonolide A was assembled in an enantioconvergent manner through the application of stereoselective hydroboration, allylation, and oxidation. This concise route may provide a realistic solution for accessing derivatives and analogues.
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Murray,Williams
, p. 1891 (1969)
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Hydrovinylation of Norbornene. Ligand-Dependent Selectivity and Asymmetric Variations
Kumareswaran, Ramaiah,Nandi, Malay,RajanBabu
, p. 4345 - 4348 (2003)
(Equation presented) Norbornene undergoes Ni-catalyzed (1-2 mol% allylnickel bromide/phosphine/NaBARF or AgSbF6, 1 bar ethylene, -50°C) hydrovinylation (>97% yield), giving either a 1:1 or a 2:1 (norbornene/ethylene) adduct depending on the size of the phosphine. Use of binaphthol-derived phosphoramidite ligand results in up to 80% ee for the 1:1 adduct. The course of the reaction is highly dependent on the ligand (size and configuration of the appendages) and the counteranion present.
An epoxidation approach to a chiral lactone: Application of the Shi epoxidation
Ager, David J.,Anderson, Ken,Oblinger, Eric,Shi, Yian,Vanderroest, James
, p. 44 - 51 (2007)
The large-scale epoxidation of the alkene 7 with the organo-catalyst, Epoxone (10), and Oxone as the oxidant is described. This is the first large-scale application of the Shi epoxidation methodology. The large-scale preparation of the catalyst 10 is also described. The potassium salt of the unsaturated acid precursor 7 was prepared by a Suzuki coupling from 3-fluorobenzyl chloride and the vinylborane 8 derived from 4-pentynoic acid.
Extension of Pd-Mediated One-Pot Ketone Synthesis to Macrocyclization: Application to a New Convergent Synthesis of Eribulin
Lee, Jung Hwa,Li, Zhanjie,Osawa, Ayumi,Kishi, Yoshito
, p. 16248 - 16251 (2016)
Recently reported Pd-mediated one-pot ketone synthesis from an unactivated alkyl bromide and a thioester has been extended to a macrocyclic ketone synthesis. In situ generation of alkylzinc halide via single electron transfer (SET), using NbCpCl4 and CrCl3, was the key for the success of macrocyclization. A new convergent synthesis of eribulin has been achieved, using (1) catalytic asymmetric Ni/Cr-mediated coupling to form the C19-C20 bond, (2) base-induced cyclization to form the methylenetetrahydrofuran ring, and (3) Pd-mediated one-pot ketone synthesis to form the macrocyclic ketone.
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Brown,H.C.,Zweifel,G.
, p. 3222 - 3223 (1960)
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Brown,Zweifel
, p. 1241,1243 (1961)
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First synthesis of both 1-aryl-4-[(E)-alk-1-enyl]-1H-1,2,3-triazoles and 1-aryl-4-[(Z)-1-(trimethylsilyl)alk-1-enyl]-1H-1,2,3-triazoles: assembly of π-extended 1,2,3-triazoles using a cross-coupling/click reaction sequence
Oikawa, Asuka,Kindaichi, Gan,Shimotori, Yasutaka,Hoshi, Masayuki
, p. 4205 - 4213 (2016)
A practical and general synthetic approach to a series of π-extended 1,2,3-triazoles with both aryl and alkenyl moieties on the triazole ring is described. Synthesis of 1-aryl-4-[(E)-alk-1-enyl]-1H-1,2,3-triazoles can be achieved by the click reaction between terminal conjugated (E)-enynes, prepared by copper-mediated cross-coupling reaction of (E)-alk-1-enyldisiamylboranes with (trimethylsilyl)ethynyl bromide, and aryl azides, prepared from arylboronic acids and sodium azide in another flask and employed for the following click reaction without any purification. 1-Aryl-4-[(Z)-1-(trimethylsilyl)alk-1-enyl]-1H-1,2,3-triazoles can be also synthesized by a sequential three-step reaction, which involves copper-mediated cross-coupling reaction of (Z)-1-(trimethylsilyl)alk-1-enyldicyclohexylboranes with (trimethylsilyl)ethynyl bromide to form (Z)-1,3-bis(trimethylsilyl)alk-3-en-1-ynes, deprotection of the trimethylsilyl group on the alkynyl carbon atom to generate (Z)-3-(trimethylsilyl)alk-3-en-1-ynes and click reaction with aryl azides prepared in the same manner as described above. Both synthetic routes are tolerant of a wide range of functional groups with moderate to good yields.
Synthesis and biological activity of the C'D'E'F' ring system of maitotoxin
Kunitake, Masahiro,Oshima, Takahiro,Konoki, Keiichi,Ebine, Makoto,Torikai, Kohei,Murata, Michio,Oishi, Tohru
, p. 4948 - 4962 (2014)
Stereoselective synthesis of the C'D'E'F' ring system of maitotoxin was achieved starting from the E' ring through successive formation of the D' and C' rings based on SmI2-mediated reductive cyclization. Construction of the F' ring was accomplished via Suzuki-Miyaura cross-coupling with a side chain fragment and Pd(II)-catalyzed cyclization of an allylic alcohol. The C'D'E'F' ring system inhibited maitotoxin-induced Ca2+ influx in rat glioma C6 cells with an IC50 value of 59 μM.
Synthesis of the all-cis-trimethyldecalin fragment of unusual terpenes by radical-mediated protonolysis of an alkylboron derivative
Villa, Giorgio,Bradshaw, Ben,Bürki, Cédric,Bonjoch, Josep,Renaud, Philippe
, p. 4608 - 4611 (2014)
The synthesis of an enantiopure building-block with a contiguous all-cis-trimethyldecalin motif embedded in unusual terpenes is described. Starting from the Wieland-Miescher ketone, the key step is a one-pot hydroboration of an exocyclic methylene double bond promoted by disiamylborane and radical-mediated protonolysis of the corresponding alkylborane using 4-tert-butylcatechol.
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Hubbard,J.L.,Kramer,G.W.
, p. 81 - 94 (1978)
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Nugent,M.J.,Vigo,T.L.
, p. 2203 - 2206 (1969)
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