Cobalt-catalyzed C2α-acyloxylation of 2-substituted indoles with tert-butyl peresters

2019 ◽  
Vol 17 (13) ◽  
pp. 3343-3347
Author(s):  
Yuxiang Zhou ◽  
Chenglong Li ◽  
Xiaoyan Yuan ◽  
Feiyan Zhang ◽  
Xiaozu Liu ◽  
...  

An efficient cobalt-catalyzed C2α selective C(sp3)–H acyloxylation of 2-substituted indoles with tert-butyl peresters to synthesize diverse 2α-acyloxylated indole derivatives is described. This developed method exhibits mild conditions, low-cost catalyst, and high functional group compatibility. The effectiveness of this chemistry is illuminated by a late-stage modification of methylated indomethacin.

2021 ◽  
Author(s):  
Ru Cui ◽  
Jie Sheng ◽  
Bing-Bing Wu ◽  
Duo-Duo Hu ◽  
Hong-Qian Zheng ◽  
...  

A nickel-catalysed direct terminal monofluormethlyation between alkyl tosylates and a low-cost, industrial raw material bromofluoromethane has been developed. This transformation has demonstrated high efficiency, mild conditions, and good functional-group compatibility....


Synthesis ◽  
2020 ◽  
Vol 52 (24) ◽  
pp. 3881-3890
Author(s):  
Jie Li ◽  
Lei Liu ◽  
Zhao Zhang ◽  
Yucheng Wang ◽  
Yan Zhang

Cobalt(III)-catalyzed electrophilic amination of inert C(sp3)–H bonds of weakly coordinating thioamides with readily accessible anthranil derivatives was accomplished under mild conditions, with good functional group tolerance, thus providing various amino aldehydes and amino ketones. Moreover, our protocol with the versatile [Cp*Co(MeCN)3][SbF6]2 features excellent atom-economy and oxidant-free conditions, and allows facile late-stage functionalization.


Synthesis ◽  
2017 ◽  
Vol 49 (17) ◽  
pp. 3937-3944 ◽  
Author(s):  
Deepti Kalsi ◽  
Nagaraju Barsu ◽  
Pardeep Dahiya ◽  
Basker Sundararaju

A simple efficient, atom-economical procedure was developed for the cobalt-catalyzed C–H bond annulation of benzamides with isonitriles under mild conditions. The reaction tolerates a variety of functional group including heterocycles. Diverse 3-(alkylimino)-2-quinolin-8-yl-2,3-dihydro-1H-isoindol-1-ones were synthesized using isonitriles as the C1 source through C–H and N–H bond annulation via C–H bond activation in a ‘green’ solvent. Vinylamides were also used similarly with tert-butyl isonitrile to give 3-(tert-butylimino)-1-quinolin-8-yl-1H-pyrrol-2(5H)-ones.


2021 ◽  
Author(s):  
Ya-Xuan Zhang ◽  
Kang-Jie Bian ◽  
Ruoxing Jin ◽  
Chi Yang ◽  
Xi-Sheng Wang

An efficient copper-catalyzed 1,2-difunction of alkenes with commercially available BrCH2Cl as a chloromethylating source, in which mild conditions, high reactivity, excellent functional-group tolerance, and late-stage modification of bioactive molecule have...


2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.


Synlett ◽  
2021 ◽  
Author(s):  
Xianqing Wu ◽  
Mohini Shrestha ◽  
Yifeng Chen

AbstractChiral-auxiliary-mediated synthesis represents the most frequently used synthetic tool for the induction of chirality on α-position of γ-lactams in organic synthesis. However, the general strategy requires the stoichiometric use of chiral reagents with multiple manipulation steps. Transition-metal-catalyzed asymmetric alkene dicarbofunctionalization using readily available substrates under mild conditions allows the simultaneous construction of two vicinal chemical bonds and a chiral carbon center, hence, gain expedient access to chiral heterocycles. Herein, we disclose a Ni-catalyzed enantioselective reaction of 3-butenyl carbamoyl chloride and primary alkyl iodide enabled by a newly designed chiral 8-quinoline imidazoline ligand (8-Quinim). This protocol features broad functional group tolerance and high enantioselectivities, achieving unprecedented synthesis of chiral nonaromatic heterocycles via catalytic reductive protocol.1 Introduction2 Development of 8-Quinim Ligand3 Nickel/8-Quinim-Catalyzed Enantioselective Synthesis of Chiral α-Alkylated γ-Lactam4 Conclusion and Outlook


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shi Cao ◽  
Wei Hong ◽  
Ziqi Ye ◽  
Lei Gong

AbstractThe direct and selective C(sp3)-H functionalization of cycloalkanes and alkanes is a highly useful process in organic synthesis owing to the low-cost starting materials, the high step and atom economy. Its application to asymmetric catalysis, however, has been scarcely explored. Herein, we disclose our effort toward this goal by incorporation of dual asymmetric photocatalysis by a chiral nickel catalyst and a commercially available organophotocatalyst with a radical relay strategy through sulfur dioxide insertion. Such design leads to the development of three-component asymmetric sulfonylation involving direct functionalization of cycloalkanes, alkanes, toluene derivatives or ethers. The photochemical reaction of a C(sp3)-H precursor, a SO2 surrogate and a common α,β-unsaturated carbonyl compound proceeds smoothly under mild conditions, delivering a wide range of biologically interesting α-C chiral sulfones with high regio- and enantioselectivity (>50 examples, up to >50:1 rr and 95% ee). This method is applicable to late-stage functionalization of bioactive molecules, and provides an appealing access to enantioenriched compounds starting from the abundant hydrocarbon compounds.


2021 ◽  
Author(s):  
Zhi-Peng Han ◽  
Mengmeng Xu ◽  
Rui-Ying Zhang ◽  
Xiao-Ping Xu ◽  
Shun-Jun Ji

Rhodium-catalyzed synthesis of indoloquinazoline from readily available hypervalent iodonium reagent and N-carboxamide indole was developed. The protocol features broad functional group tolerance, mild conditions, excellent yields and simple workup. Notably,...


RSC Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 5080-5085
Author(s):  
Lei Zheng ◽  
Chen Sun ◽  
Wenhao Xu ◽  
Alexandr V. Dushkin ◽  
Nikolay Polyakov ◽  
...  

We have developed I2/KH2PO2 and KI/P(OEt)3 strategy syntheses of esters from carboxylic acids and alcohols through different reaction mechanisms. The advantages of present protocol: mild conditions and late-stage diversification of natural products.


2021 ◽  
pp. 174751982110325
Author(s):  
Yan Xiao ◽  
Jiyu Gao ◽  
Peng Chen ◽  
Guangliang Chen ◽  
Zicheng Li ◽  
...  

A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.


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