- A simple method for synthesis of active esters of isonicotinic and picolinic acids
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A method for preparation of the p-nitrophenyl-, N-hydroxysuccinimidyl- and pentafluorophenyl esters of isonicotinic and picolinic acids from the corresponding acids is reported.
- Christensen, Jorn B.
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- Transesterification of (hetero)aryl esters with phenols by an Earth-abundant metal catalyst
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Readily available and inexpensive Earth-abundant alkali metal species are used as efficient catalysts for the transesterification of aryl or heteroaryl esters with phenols which is a challenging and underdeveloped transformation. The simple conditions and the use of heterogeneous alkali metal catalyst make this protocol very environmentally friendly and practical. This reaction fills in the missing part in transesterification reaction of phenols and provides an efficient approach to aryl esters, which are widely used in the synthetic and pharmaceutical industry.
- Chen, Jianxia,Namila,Bai, Chaolumen,Baiyin, Menghe,Agula, Bao,Bao, Yong-Sheng
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p. 25168 - 25176
(2018/07/29)
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- Total Synthesis and Biological Evaluation of Natural and Designed Tubulysins
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A streamlined total synthesis of N14-desacetoxytubulysin H (Tb1) based on a C-H activation strategy and a short total synthesis of pretubulysin D (PTb-D43) are described. Applications of the developed synthetic strategies and technologies to the synthesis of a series of tubulysin analogues (Tb2-Tb41 and PTb-D42) are also reported. Biological evaluation of the synthesized compounds against an array of cancer cells revealed a number of novel analogues (e.g., Tb14), some with exceptional potencies against certain cell lines [e.g., Tb32 with IC50 = 12 pM against MES SA (uterine sarcoma) cell line and 2 pM against HEK 293T (human embryonic kidney) cell line], and a set of valuable structure-activity relationships. The highly potent cytotoxic compounds discovered in this study are highly desirable as payloads for antibody-drug conjugates and other drug delivery systems for personalized targeted cancer chemotherapies.
- Nicolaou,Yin, Jun,Mandal, Debashis,Erande, Rohan D.,Klahn, Philipp,Jin, Michael,Aujay, Monette,Sandoval, Joseph,Gavrilyuk, Julia,Vourloumis, Dionisios
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supporting information
p. 1698 - 1708
(2016/02/20)
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- DESACETOXYTUBULYSIN H AND ANALOGS THEREOF
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In one aspect, the present disclosure provides tubulysin analogs of the formula (I) wherein R1, R2, R3, R4, X1, X2, X3, and A1 are as defined herein. In another aspect, the present disclosure also provides methods of preparing the compounds disclosed herein. In another aspect, the present disclosure also provides pharmaceutical compositions and methods of use of the compounds disclosed herein.
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Page/Page column 104-105
(2016/09/22)
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- HERBICIDALLY ACTIVE 2-(SUBSTITUTED-PHENYL)-CYCLOPENTANE-1,3-DIONE COMPOUNDS AND DERIVATIVES THEREOF
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The present invention relates to a compound of formula (I): wherein the substituents are as defined herein, and wherein the compound of formula (I) is optionally present as an agrochemically acceptable salt thereof. These compounds are thought to be suitable for use as herbicides. The invention therefore also relates to a method of controlling weeds, especially grassy monocotyledonous weeds, in crops of useful plants, comprising applying a compound of formula (I), or a herbicidal composition comprising such a compound, to the plants or to the locus thereof.
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Page/Page column 143-144
(2014/11/11)
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- Aminolysis of aryl ester using tertiary amine as amino donor via c-o and c-n bond activations
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An aminolysis reaction between various aryl esters and inert tertiary amines by C-O and C-N bond activations has been developed for the selective synthesis of a broad scope of tertiary amides under neutral and mild conditions. The mechanism may undergo the two key steps of oxidative addition of acyl C-O bond in parent ester and C-N bond cleavage of tertiary amine via an iminium-type intermediate.
- Bao, Yong-Sheng,Zhaorigetu, Bao,Agula, Bao,Baiyin, Menghe,Jia, Meilin
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p. 803 - 808
(2014/04/03)
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- Energy-efficient green catalysis: Supported gold nanoparticle-catalyzed aminolysis of esters with inert tertiary amines by C-O and C-N bond activations
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Catalyzed by supported gold nanoparticles, an aminolysis reaction between various aryl esters and inert tertiary amines by C-O and C-N bond activations has been developed for the selective synthesis of tertiary amides. Comparison studies indicated that the gold nanoparticles could perform energy-efficient green catalysis at room temperature, whereas Pd(OAc)2 could not.
- Bao, Yong-Sheng,Baiyin, Menghe,Agula, Bao,Jia, Meilin,Zhaorigetu, Bao
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p. 6715 - 6719
(2014/08/05)
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- Transesterification for synthesis of carboxylates using aldehydes as acyl donors via C-H and C-O bond activations
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A new type of transesterification between aryl, heteroaryl, alkyl N-heteroarene-2-carboxylates and various aldehydes by C-H and C-O bond activations has been developed for the synthesis of versatile carboxylates. A possible mechanism containing oxidative addition of acyl-O bond in parent ester and radical cleavage of sp2 C-H bond in aldehyde is proposed.
- Bao, Yong-Sheng,Chen, Chao-Yue,Huang, Zhi-Zhen
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p. 8344 - 8349,6
(2020/10/15)
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- Convenient syntheses of 1,1,1,3,3,3-hexafluoro-2-organyl-propan-2-ols and the corresponding trimethylsilyl ethers
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A new convenient synthetic procedure to obtain various 1,1,1,3,3,3- hexafluoro-2-organyl-propan-2-ols and the corresponding trimethylsilyl ethers has been worked out starting from anhydrides or activated esters of carboxylic acids and trimethyl(trifluoromethyl)silane in the presence of tetramethylammonium fluoride. Conditions for the selective formation of 1,1,1,3,3,3-hexafluoro-2-organyl-propan-2-ols as well as the trimethylsilyl derivatives have been found.
- Babadzhanova,Kirij,Yagupolskii,Tyrra,Naumann
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p. 1813 - 1819
(2007/10/03)
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- Pentafluorophenyl ester activation for the preparation of N,N'-diaroylhydrazines
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Procedures are reported for the preparation of N,N'-diaroylhydrazines using pentafluorophenyl (Pfp) ester activation of aryl carboxylic acids. Mild conditions which avoid intermediate protection of ring substituents, allows the synthesis of both symmetrical and unsymmetrical diaroylhydrazines in high yields. The recent discovery of potent HIV-1 integrase inhibition by N,N'-bis-salicylhydrazine (1) highlights the potential importance of this class of compounds. The stability of pre-activated Pfp ester intermediates and the facility with which N,N'-diaroylhydrazines can be synthesized using this procedure (stirring at room temperature in DMF) may make the method particularly attractive for synthesis of hydrazide libraries.
- Zhao, He,Burke Jr., Terrence R.
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p. 4219 - 4230
(2007/10/03)
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