Auxiliary-assisted palladium-catalyzed halogenation of unactivated C(sp3)–H bonds at room temperature

2016 ◽  
Vol 52 (38) ◽  
pp. 6423-6426 ◽  
Author(s):  
Xinglin Yang ◽  
Yonghui Sun ◽  
Tian-yu Sun ◽  
Yu Rao

The direct transformation of unactivated C(sp3)–H bonds into C-halogen bonds was achieved by palladium catalysis at room temperature with good functional group tolerance.

2015 ◽  
Vol 51 (80) ◽  
pp. 14929-14932 ◽  
Author(s):  
Jiantao Hu ◽  
Tianlong Lan ◽  
Yihua Sun ◽  
Hui Chen ◽  
Jiannian Yao ◽  
...  

A novel palladium catalyzed hydroxylation of unactivated aliphatic C(sp3)–H bonds was successfully developed. Different from conventional methods, water serves as the hydroxyl group source in the reaction. This reaction demonstrates broad functional group tolerance.


Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2581-2586 ◽  
Author(s):  
Wen-Jun Zhou ◽  
Da-Gang Yu ◽  
Yong-Yuan Gui ◽  
Xiao-Wang Chen

The arylation of amide and urea C(sp3)–H bonds with aryl tosylates generated in situ from phenols has been realized at room temperature by combining visible-light-photoredox catalysis, hydrogen-atom-transfer catalysis, and nickel catalysis. This streamlined protocol permits rapid functionalization of phenols and direct transformation of α-amino C(sp3)–H bonds. The C(sp3)–H arylation products are obtained in high yields with good functional-group tolerance at low catalyst loadings.


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.


2010 ◽  
Vol 31 (10) ◽  
pp. 1277-1280
Author(s):  
Chun LIU ◽  
Qijian NI ◽  
Pingping HU ◽  
Hao YUAN ◽  
Zilin JIN

1987 ◽  
Vol 52 (4) ◽  
pp. 970-979 ◽  
Author(s):  
Otto Exner ◽  
Pavel Fiedler

Aromatic chloroformates Ib-Ie were shown to exist in the ap conformation, in agreement with aliphatic chloroformates, i.e. the alkyl group is situated cis to the carbonyl oxygen atom as it is the case in all esters. While 4-nitrophenyl chloroformate (Ie) is in this conformation in crystal, in solution at most several tenths of percent of the sp conformation may be populated at room temperature and in nonpolar solvents only. A new analysis of dipole moments explained the previous puzzling results and demonstrated the impossibility to determine the conformation by this single method, in consequence of the strong interaction of adjoining bonds. If, however, the ap conformation is once proven, the dipole moments reveal some features of the electron distribution on the functional group, characterized by the enhanced polarity of the C-Cl bond and reduced polarity of the C=O bond. This is in agreement with the observed bond lengths and angles.


Synthesis ◽  
2021 ◽  
Author(s):  
Hongji Li ◽  
Wenjie Zhang ◽  
Xueyan Liu ◽  
Zhenfeng Tian

AbstractWe herein report a new nitrogen-directed Rh(III)-catalyzed C(sp2)–H bond functionalization of N-nitrosoanilines and azoxybenzenes with maleimides as a coupling partner, in which the olefination/alkylation process can be finely controlled at room temperature by variation of the reaction conditions. This method shows excellent functional group tolerance, and presents a mild access to the resulting olefination/alkylation products in moderate to good yields.


Author(s):  
Pan Xie ◽  
Cheng Xue ◽  
Cancan Wang ◽  
Dongdong Du ◽  
Sanshan Shi

A CF3SO2Na/Pd(OAc)2 co-catalyzed strategy is developed to produce aryl ketones via visible-light-induced decarboxylative cross-coupling of α-oxocarboxylic acids and aryl boronic acids. This process was perfomed under air at room temperature,...


2021 ◽  
Vol 57 (16) ◽  
pp. 2021-2024
Author(s):  
Zhi-Chao Qi ◽  
Qin-Xin Lou ◽  
Yuan Niu ◽  
Shang-Dong Yang

An efficient palladium-catalyzed, temporary P(O) directing group assisted C–H bond arylation of carbazoles was achieved, accompanied by the directing group being self-shed spontaneously.


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