Palladium-catalyzed asymmetric allylic amination of racemic butadiene monoxide with isatin derivatives

2015 ◽  
Vol 13 (20) ◽  
pp. 5826-5830 ◽  
Author(s):  
Gen Li ◽  
Xiangqing Feng ◽  
Haifeng Du

Pd-catalyzed asymmetric aminations of butadiene monoxide with isatin derivatives using P/alkene ligands gave high yields, ees and regioselectivity ratios.

2013 ◽  
Vol 85 (6) ◽  
pp. 1089-1101 ◽  
Author(s):  
Shū Kobayashi

Different reactivities and selectivities are observed in water compared with those in organic solvents. In this article, such three examples are described. While ammonia was known not to react in metal-catalyzed allylic amination, palladium-catalyzed allylic amination using aqueous ammonia proceeded to afford primary amines in high yields. Second, allylboronates reacted with aldehydes in aqueous media to afford α-addition adducts exclusively in high yields with high diastereo- and enantioselectivities using Zn(OH)2with ligands as catalysts. Finally, it was found that catalytic use of In(0) was effective for the reactions of allylboronates with ketones in water.


2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>


2020 ◽  
Author(s):  
Evgeny Tretyakov ◽  
Svetlana Zhivetyeva ◽  
Pavel Petunin ◽  
Dmitry Gorbunov ◽  
Nina Gritsan ◽  
...  

<p>Verdazyl-nitroxide diradicals were synthesized using the palladium-catalyzed cross-coupling reaction of the corresponding iodoverdazyls with a nitronyl nitroxide-2-ide gold(I) complex with high yields (up to 82%). The synthesized diradicals were found to be highly thermally stable and have a singlet (D<i>E</i><sub>ST</sub> » -64 cm<sup>–1</sup>) or triplet ground state (D<i>E</i><sub>ST</sub> ³ 25 and 100 cm<sup>–1</sup>), depending on which canonical hydrocarbon diradical type they belong to. Upon crystallization, triplet diradicals form unique one-dimensional (1D) spin <i>S</i> = 1 chains of organic diradicals with intrachain ferromagnetic coupling of <i>J</i>′/<i>k</i><sub>B</sub> from 3 to 6 K.</p>


2021 ◽  
Vol 43 (1) ◽  
pp. 95-95
Author(s):  
Rifhat Bibi Rifhat Bibi ◽  
Muhammad Yaseen Muhammad Yaseen ◽  
Haseen Ahmad Haseen Ahmad ◽  
Ismat Ullah Khan Ismat Ullah Khan ◽  
Shaista Parveen Shaista Parveen ◽  
...  

Transition metals mediated cross coupling methodologies provide an extremely powerful versatile pathway in organic syntheses undoubtedly, a facile route for syntheses and derivatization of biologically important heterocycles from easily available precursors. Sonogashira coupling reaction, a leading method to Csp-Csp2 bond formation is one of the most important and rapid pathways to couple aryl/vinyl halides with terminal alkynes. Current research study deals with the synthesis of alkyne substituted quinoxaline derivatives. The quinoxalines class of aromatic heterocycles exhibits a wide variety of important biological potencies. Palladium catalyzed cross coupling process provided an effective synthetic practice for the synthesis of alkyne derivatives of quinoxaline. Vareity of terminal alkynes were coupled with 2-(4-bromophenyl)quinoxaline under optimized conditions for Sonogashira reaction, affording alkyne substituted quinoxaline derivatives in high yields. The optimized reaction conditions for coupling of range of terminal alkyne with quinoxaline basic core render this process significant for designing of medicinally interesting precursors.


Synthesis ◽  
2021 ◽  
Author(s):  
Antonella Goggiamani ◽  
Antonia Iazzetti ◽  
Antonio Arcadi ◽  
Andrea Calcaterra ◽  
Marco Chiarini ◽  
...  

AbstractThe palladium-catalyzed synthesis of indole/benzofuran-containing diarylmethanes starting from indolylmethyl or benzofuranylmethyl acetates with boronic acids has been investigated. The success of the reaction is influenced by the choice of precatalyst: with indolylmethyl acetates the reaction works well with [Pd(η3-C3H5)Cl]2/XPhos while with benzofuranylmethyl acetates Pd2(dba)3/XPhos is more efficient. The good to high yields and the simplicity of the experimental procedure make this protocol a versatile synthetic tool for the preparation of 2- and 3-substituted indoles and 2-benzo[b]furans. The methodology can be advantageously extended to the preparation of a key precursor of Zafirlukast.


Synthesis ◽  
2017 ◽  
Vol 49 (16) ◽  
pp. 3662-3669 ◽  
Author(s):  
Xiao-Yu Zhou ◽  
Xia Chen ◽  
Liang-Guang Wang ◽  
Dan Yang ◽  
Zhi Li

The palladium-catalyzed oxidation-hydroxylation and oxidation-methoxylation of N-Boc indoles for the synthesis of tert-butyl 2-hydroxy(methoxy)-3-oxoindoline-1-carboxylates and their derivatives is developed. The process occurs readily using PdCl2 as the catalyst and acetonitrile as the solvent to afford 3-oxoindolines in moderate to high yields. A mechanism for this Pd-catalyzed oxidation-hydroxylation and oxidation-methoxylation of N-Boc indoles is proposed.


Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2387-2394 ◽  
Author(s):  
Jorge A. Cabezas ◽  
Natasha Ferllini

A regiospecific palladium-catalyzed cross-coupling reaction using the operational equivalent of the dianion 1,3-dilithiopropyne, with aromatic iodides is reported. This reaction gives high yields of 1-propyn-1-yl-benzenes and 2-(propyn-1-yl)thiophenes in the presence of catalytic amounts of palladium(0) or (II) and stoichiometric amounts of copper iodide. No terminal alkyne or allene isomers were detected. Reaction conditions were very mild and several functional groups were tolerated.


2020 ◽  
Vol 18 (23) ◽  
pp. 4390-4394
Author(s):  
Jia-Hui Zhao ◽  
Zhao-Zhao Zhou ◽  
Yue Zhang ◽  
Xuan Su ◽  
Xi-Meng Chen ◽  
...  

Palladium catalyzed visible-light-mediated borylation of inactivated aryl and alkyl halides is reported; the method provided high yields and excellent functional group compatibility.


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