Search

Your search keyword '"Xian Chen"' showing total 16 results
Start Over Author "Xian Chen" Journal organic letters
16 results on '"Xian Chen"'

9. Ir(III)-Catalyzed Mono-Olefination of Aryl C–H Bonds Using −SCF3 as a Weak Directing Group

Author

Xian Chen, Rui-Peng Bao, Donghui Wang, and Chen Li

Subjects
Bipyridine, chemistry.chemical_compound, chemistry, Group (periodic table), Ligand, Aryl, Organic Chemistry, Physical and Theoretical Chemistry, Cleavage (embryo), Biochemistry, Medicinal chemistry, Catalysis
Abstract

The trifluoromethylthionyl group (-SCF3) is an efficient weak directing group for Ir(III)-catalyzed aryl C-H olefination. Various trifluoromethylthioethers provide high levels of mono-olefination products in good to excellent yields under mild conditions with a 2,2'-bipyridine ligand or AgBF4 as an additive. Mechanistic studies indicate the C-H cleavage is the rate-determining step. The directing group ability of the -SCF3 group is benchmarked against several other weak directing groups by competition experiments under Ir(III)-catalyzed conditions.

Published
2019

10. Phosphonium Ylide-Mediated Programmable Fluorination to Access Mono- and Difluoromethylarenes

Author

Xiaoqing Chen, Wen-Shuo Cheng, Zhen-Zhen Xie, Kai Chen, Hao-Yue Xiang, Xian-Chen He, Hua Yang, Yan-Shan Chen, and Yu Zheng

Subjects
chemistry.chemical_classification, 010405 organic chemistry, Organic Chemistry, 010402 general chemistry, 01 natural sciences, Biochemistry, Combinatorial chemistry, Chemical synthesis, 0104 chemical sciences, chemistry.chemical_compound, Deprotonation, Reaction sequence, chemistry, Ylide, Phosphonium, Physical and Theoretical Chemistry
Abstract

Compounds bearing fluorinated moieties are pervasive in a wide range of pharmaceuticals and agrochemicals. The installation of fluorinated units is a persistently vital task in synthetic chemistry, where facile and manipulable assays are highly demanding. Herein, we establish a general and programmable fluorination strategy for the modular assembly of mono- and difluoromethylarenes through the controllable deprotonation and fluorination of phosphonium ylides. Moreover, the rational combination of the reaction sequence allows the rapid construction of diversified fluorine-containing arenes.

Published
2021

15. Photoredox/Nickel Dual Catalysis-Enabled Aryl Formylation with 2,2-Dimethoxy- N , N -dimethylethan-1-amine as CO Source.

Author

Gao J, He XC, Liu YL, Yao PP, Guan JP, Chen K, Xiang HY, and Yang H

Abstract

Herein, a dual photoredox/nickel catalyzed formylation of aryl bromide with commercially available 2,2-dimethoxy- N , N -dimethylethan-1-amine as an effective CO source has been successfully achieved, delivering a series of aromatic aldehydes in moderate to good yields. Compared with the traditional reductive carbonylation process, this newly designed synthetic protocol provides a straightforward toolbox to access aromatic aldehydes, obviating the use of carbon monoxide and stoichiometric reductants. Finally, the utility of this direct formylation reaction was demonstrated in the pharmaceutical analogue synthesis.

Published
2024
Full Text
View/download PDF

16. Photoexcited Ni II -Aryl Complex-Mediated Giese Reaction of Aryl Bromides.

Author

He XC, Li KR, Gao J, Guan JP, Chen HB, Xiang HY, Chen K, and Yang H

Subjects
Catalysis, Nickel, Electrons, Bromides, Alkenes
Abstract

A Giese reaction of aryl bromides with electron-deficient alkenes was developed, enabled by a dual catalyst system containing Ni II complex and Ir III photocatalyst. This protocol could accommodate a variety of aryl bromides and electron-deficient alkenes, delivering the conjugate adducts in up to 97% yield. The utilization of photoexcited (dtbbpy)Ni II (aryl)Br intermediate as an aryl radical source allows this novel transformation of aryl halides, thus expanding the chemical space of excited nickel catalysis.

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results