scholarly journals Manganese/bipyridine-catalyzed non-directed C(sp3)–H bromination using NBS and TMSN3

2021 ◽  
Vol 17 ◽  
pp. 885-890
Author(s):  
Kumar Sneh ◽  
Takeru Torigoe ◽  
Yoichiro Kuninobu

A Mn(II)/bipyridine-catalyzed bromination reaction of unactivated aliphatic C(sp3)−H bonds has been developed using N-bromosuccinimide (NBS) as the brominating reagent. The reaction proceeded in moderate-to-good yield, even on a gram scale. The introduced bromine atom can be converted into fluorine and allyl groups.

2019 ◽  
Author(s):  
Tristan Delcaillau ◽  
Alessandro Bismuto ◽  
Zhong Lian ◽  
Bill Morandi

A nickel-catalyzed carbon-sulfur bond metathesis has been developed to access high-value thioethers. 1,2-bis(dicyclohexylphosphino)ethane (dcype) is essential to promote this highly functional group tolerant reaction. Further, synthetically challenging macrocycles could be obtained in good yield in an unusual example of ring-closing metathesis which does not involve alkene bonds. In-depth organometallic studies support a reversible Ni(0)-Ni(II) pathway to product formation. Overall, this work does not only disclose a more sustainable and more functional group tolerant alternative to previous catalytic systems based on Pd, but also presents new applications and mechanistic information which are highly relevant to the further development and application of unusual single bond metathesis reactions.


2012 ◽  
Vol 29 (2) ◽  
pp. 135
Author(s):  
Junhong DING ◽  
Shuwen GONG ◽  
Lijun LIU ◽  
Kaozhen LI ◽  
Qingxin CUI

2018 ◽  
Vol 16 (1) ◽  
pp. 34-39
Author(s):  
Yao-Wei Li ◽  
Pei-Ming Zhang ◽  
Rui Li ◽  
Yan Bai ◽  
Yu Yu ◽  
...  

CDI combined with CH3SO3H was found to be highly effective for the cyclization of 2-aminothiophenol derivatives with carboxylic acids under MW condition. Fourteen benzothiazole derivatives were synthesized in good yield and their structures were characterized by 1H-NMR, 13CNMR, IR and mass spectrometry. This simple, rapid synthetic method is believed to provide a useful process for the synthesis of 2-substituted benzothiazole compounds.


1974 ◽  
Vol 27 (10) ◽  
pp. 2205 ◽  
Author(s):  
T Fujita ◽  
S Watanabe ◽  
K Suga

Lithium naphthalenide reacts with carboxylic acids in the presence of diethylamine to give the α-anions of lithium carboxylates. Reaction of these anions with various epoxides gives the corresponding y-hydroxy acids in good yield. The γ-hydroxy acids easily cyclize to give γ-butyrolactones.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1505
Author(s):  
Kyle N. Hearn ◽  
Trent D. Ashton ◽  
Rameshwor Acharya ◽  
Zikai Feng ◽  
Nuri Gueven ◽  
...  

Methodology to access fluorescent 3-amido-1,8-naphthalimides using direct Buchwald–Hartwig amidation is described. The protocol was successfully used to couple a number of substrates (including an alkylamide, an arylamide, a lactam and a carbamate) to 3-bromo-1,8-naphthalimide in good yield. To further exemplify the approach, a set of scriptaid analogues with amide substituents at the 3-position were prepared. The new compounds were more potent than scriptaid at a number of histone deacetylase (HDAC) isoforms including HDAC6. Activity was further confirmed in a whole cell tubulin deacetylation assay where the inhibitors were more active than the established HDAC6 selective inhibitor Tubastatin. The optical properties of these new, highly active, compounds make them amenable to cellular imaging studies and theranostic applications.


1982 ◽  
Vol 37 (12) ◽  
pp. 1640-1647 ◽  
Author(s):  
Bernd Sorg ◽  
Erich Hecker

3-Deoxy-3-oxoingenol (3) was prepared from ingenol-5,20-acetonide (25) by oxidation and subsequent removal of the acetonide. 3 was acylated to give homologous 5,20-diacylates 5-9. From these the 5-monoacylates 14, 15 and 17 were obtained in only moderate yields. Therefore the 20-silyl ether 10 (prepared from 3) was acylated. After smooth removal of the silyl ether the homologous 5-acylates 16. 18 and 19 resulted in good yield. The 5,20-dibutyrate 6 and all 5-acylates prepared (14-19) showed no irritant activity on the mouse ear. The 3-oxo-5-acylates 14-19 could not be reduced to give ingenol-5-acylates (24). Therefore various ingenol derivatives, 29-32, with suitable protected hydroxyl functions as well as the corresponding 5-clecanoates 35-38 were synthesized. The protecting groups of the derivatives 35-38 could however not be cleaved off to yield ingenol-5- decanoate (24)


2014 ◽  
Vol 662 ◽  
pp. 59-62
Author(s):  
Shan Shan Gong ◽  
Qi Sun

A facile and efficient method for the synthesis ofP1,P3-dizidovudine-5′,5′-triphosphate has been developed. The coupling of zidovudine diphosphate with zidovudine phosphoropiperidate based on the DCI activation of P-N bond afforded the desired product in good yield.


2007 ◽  
Vol 72 (13) ◽  
pp. 4756-4762 ◽  
Author(s):  
Metin Balci ◽  
Murat Güney ◽  
Arif Daştan ◽  
Akın Azizoǧlu

1977 ◽  
Vol 164 (3) ◽  
pp. 709-714 ◽  
Author(s):  
S Hayakawa ◽  
T Takata ◽  
T Fujiwara ◽  
S Hashimoto

Relatively large amounts of 3-(3aalpha-hexahydro-7abeta-methyl-1,5-dioxoindan-4alpha-yl)propionic acid (IIb), which is believed to be one of the intermediates involved in the degradation of cholic acid (I), were needed to identify is further degradation products. A simple method for the preparation of this compound was then investigated. Arthrobacter simplex could degrade-3-oxoandrost-4-ene-17beta-carboxylic acid (IIIa) to 3-(1beta-carboxy-3aalpha-hexahydro-7abeta-methyl-5-oxoindan-4alpha-yl)propionic acid (IVa) in good yield, the structure of which was established by partial synthesis. It was therefore expected that, if a similar degradation by this organism occurred with 17alpha-hydroxy-3-oxoandrost-4-ene-17beta-carboxylic acid (IIIb), which is easily obtained by chemical oxidation of commercially availabe 17alpha-hydroxydeoxycorticosterone, the resulting product, 3-(1beta-carboxy-3aalpha-hexahydro-1alpha-hydroxy-7abeta-methyl-5-oxoindan-4alpha-yl)propionic acid (IVb), could be readily converted chemically into the required dioxocarboxylic acid, (IIb). Exposure of compound (IIIb) to A. simplex produced, as expected, compound (IVb) which was then oxidized with NaBiO3 to give a reasonable yield of compound (IIb).


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