Pd-Catalyzed diastereoselective [3 + 2] cycloaddition of vinylcyclopropanes with sulfamate-derived cyclic imines

2018 ◽  
Vol 16 (26) ◽  
pp. 4881-4887 ◽  
Author(s):  
Qijun Wang ◽  
Chang Wang ◽  
Wangyu Shi ◽  
Yumei Xiao ◽  
Hongchao Guo

The palladium-catalyzed diastereoselective [3 + 2] cycloaddition reaction of vinylcyclopropanes with sulfamate-derived cyclic imines worked efficiently under mild conditions, providing sulfamate-fused pyrrolidines in good to excellent yields.

2020 ◽  
Vol 7 (18) ◽  
pp. 2612-2617
Author(s):  
Wenhao Dai ◽  
Chunpu Li ◽  
Yichu Liu ◽  
Xu Han ◽  
Xingjun Li ◽  
...  

An efficient approach to obtain saturated seven-membered ring containing three heteroatoms has been developed by using a palladium-catalyzed [4 + 3] dearomatizing cycloaddition. This approach features mild conditions and good functional group tolerance.


2012 ◽  
Vol 557-559 ◽  
pp. 1031-1036 ◽  
Author(s):  
Jian Xin Yang ◽  
Xiang Hui Wang

A series of fluorescence compounds, 4-benzofuranyl-1,8-naphthalimides, were prepared through cycloaddition reaction from 4-ethynyl-1,8-naphthalimides and o-iodophenols which catalyzed by a Pd(PPh3)2Cl2 / CuI system under mild conditions. The intermediate material, 4-ethynyl-1,8- naphthalimide, was synthesized from 4-bromo-1,8- naphthalimide and trimethylsilyl- acetylene. The absorption and fluorescence spectra of 4-benzofuranyl-1,8- naphthalimides were studied and the quantum yields were measured. The maximum UV/vis absorption spectra were in the range of 375-400 nm and the maximum emission spectra were in the range of 470-510 nm. The electro- luminescent properties were also mensurated through a doped electroluminescent device which contains 1% 1,8-naphthalimides and 99% CBP (4,4'-N,N'-dicarbazole-biphenyl), It’s shown the maximum brightness reached 3700 cd/ m2 at 22.5V.


2020 ◽  
Author(s):  
Hojoon Park ◽  
jin-quan yu

<div>Cycloaddition reactions provide an expeditious route to construct ring systems in a highly convergent and stereoselective manner. For a typical cycloaddition reaction to occur, however, the installation of multiple reactive functional groups (π-bonds, leaving group, etc.) are required within the substrates, compromising the overall efficiency or scope of the cycloaddition reaction. Here, we report a palladium-catalyzed [3+2] reaction that utilizes C(sp<sup>3</sup>)–H activation to generate the three-carbon unit for formal cycloaddition with maleimides. We implemented a strategy where the initial C(sp<sup>3</sup>)–H activation/olefin insertion would trigger a relayed, second remote C(sp<sup>3</sup>)–H activation to complete a formal [3+2] cycloaddition. The diastereoselectivity profile of this reaction resembles that of a typical pericyclic cycloaddition reaction in that the relationships between multiple stereocenters are exquisitely controlled in a single reaction. The key to success was the use of weakly coordinating amides as the directing group, as undesired Heck or alkylation pathways were preferred with other types of directing groups. The use of the pyridine-3-sulfonic acid ligands is critical to enable C(sp<sup>3</sup>)–H activation directed by this weak coordination. The method is compatible with a wide range of amide substrates, including lactams, which lead to novel spiro-bicyclic products. The [3+2] product is also shown to undergo a reductive desymmetrization process to access chiral cyclopentane bearing multiple stereocenters with excellent enantioselectivity.</div>


2016 ◽  
Vol 7 (6) ◽  
pp. 3757-3762 ◽  
Author(s):  
Jiang Wu ◽  
Yafei Liu ◽  
Changhui Lu ◽  
Qilong Shen

A palladium-catalyzed difluoromethylthiolation of heteroaryl halides and triflates under mild conditions was described.


2017 ◽  
Vol 41 (1) ◽  
pp. 372-376 ◽  
Author(s):  
Jinyi Song ◽  
Hongyan Zhao ◽  
Yang Liu ◽  
Huatao Han ◽  
Zhuofei Li ◽  
...  

A series of N,O-bidentate ligands were synthesized and studied as high activity ligands for palladium-catalyzed Suzuki–Miyaura cross-coupling reactions of aryl chlorides with arylboronic acids under mild conditions.


Synthesis ◽  
2021 ◽  
Author(s):  
Zhuo Zeng ◽  
Zhanyu He ◽  
Chu Yan ◽  
Mei Zhang ◽  
Majeed Irfan ◽  
...  

AbstractPalladium-catalyzed Hiyama coupling of active thioureas via selective C–N bond cleavage is reported. Notably, the new approach employed active thioureas as coupling partners in the presence of arylsilanes to give amides in good yield. Further, this strategy, which utilized CuF2 as a key oxidant and activator, afforded various amide products under mild conditions and an easy to handle procedure without extra base.


Synthesis ◽  
2019 ◽  
Vol 51 (22) ◽  
pp. 4215-4230 ◽  
Author(s):  
Adesh Kumar Singh ◽  
Rapelly Venkatesh ◽  
Jeyakumar Kandasamy

The palladium-catalyzed one-pot synthesis of 2,3-deoxy-3-keto aryl C-glycosides is achieved from glycals and anilines in the presence of tert-butyl nitrite and aqueous HBF4 under mild conditions. This one-pot method stereospecifically provides α- and β-aryl glycosides (≥19:1 by NMR) in good yields at room temperature. The configuration at the C-3 position in the glycal determines the anomeric selectivity (i.e., α or β) of the desired products.


2019 ◽  
Vol 17 (12) ◽  
pp. 3103-3107 ◽  
Author(s):  
Yunlong Guo ◽  
Zengming Shen

We discovered an effective and simple system (Pd/BQ/air/r.t.) for making allylic alcohols through Pd-catalyzed allylic C–H bond functionalization.


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