Rhodium-catalyzed decarbonylation cross-coupling reactions of aromatic aldehydes and arylboronic acids via C C bond activation directed by a guide group chelation

2020 ◽  
Vol 119 ◽  
pp. 108065
Author(s):  
Xiaobo Yu ◽  
Guanchen Liu ◽  
Shudong Geng
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bingnan Du ◽  
Chun-Ming Chan ◽  
Pui-Yiu Lee ◽  
Leong-Hung Cheung ◽  
Xin Xu ◽  
...  

Abstractgem-Difluoroalkene is a bioisostere of carbonyl group for improving bioavailability of drug candidates. Herein we develop structurally diverse 2,2-difluorovinyl benzoates (BzO-DFs) as versatile building blocks for modular synthesis of gem-difluoroenol ethers (44 examples) and gem-difluoroalkenes (2 examples) by Ni-catalyzed cross coupling reactions. Diverse BzO-DFs derivatives bearing sensitive functional groups (e.g., C = C, TMS, strained carbocycles) are readily prepared from their bromodifluoroacetates and bromodifluoroketones precursors using metallic zinc as reductant. With Ni(COD)2 and dppf [1,1’-bis(diphenylphosphino)ferrocene] as catalyst, reactions of BzO-DFs with arylboronic acids and arylmagnesium/alkylzinc reagents afforded the desired gem-difluoroenol ethers and gem-difluoroalkenes in good yields. The Ni-catalyzed coupling reactions features highly regioselective C(vinyl)–O(benzoate) bond activation of the BzO-DFs. Results from control experiments and DFT calculations are consistent with a mechanism involving initial oxidative addition of the BzO-DFs by the Ni(0) complex. By virtue of diversity of the BzO-DFs and excellent functional group tolerance, this method is amenable to late-stage functionalization of multifunctionalized bioactive molecules.


2004 ◽  
Vol 82 (2) ◽  
pp. 206-214 ◽  
Author(s):  
Richard W Friesen ◽  
Laird A Trimble

4,7-Dichloroquinoline (1a) and 7-chloro-4-iodoquinoline (1b) undergo Suzuki cross-coupling reactions with arylboronic acids catalyzed by phosphine-free palladium acetate in boiling water. Using phenylboronic acid (2), the reaction of 1a provides 7-chloro-4-phenylquinoline (3) (78%) together with diphenylquinoline (4) (12%), while 1b reacts in a much more regioselective fashion and provides 3 in 98% isolated yield. Although 1b undergoes a more regioselective Suzuki reaction than 1a, additional important observations are that the overall reaction of 1b with 2 is three times slower than 1a and that the reaction occurs in the absence of tetrabutylammonium bromide. Using optimized reaction conditions, a variety of aryl and vinylboronic acids undergo regioselective Suzuki cross-coupling with 1b to provide the products 7, 10, and 11 in good to excellent yield.Key words: palladium, cross-coupling, regioselectivity, quinolines, boronic acids.


2019 ◽  
Author(s):  
Dengmengfei Xiao ◽  
Lili Zhao ◽  
Diego Andrada

Unstrained cyclic ketones can participate in cooperative Suzuki-Miyaura cross-coupling type reaction using rhodium(I)-based catalyst via C-C bond activation. The regioselectivity indicates a trend where the most substituted side is activated and it is controlled by the beta-substituents. In this work, Density Functional Theory (DFT) calculations have been carried out to disclose the underlying mechanism in the reaction of a ketone series and arylboronate using ylidene as ancillary ligand and pyridine as co-catalysts. The computed energies suggest the reductive elimination step with the highest energy while the reductive elimination has the highest energy barrier. By the means of the Activation Strain Model (ASM) of chemical reactivity, it is found that the ketone strain energy released on the oxidative addition does not control the relativity of the OA reactivity, but indeed is the interaction energy between Rh(I) and C-C bond the ruling effect. The effect of the beta-substituents on regioselectivity has been additionally studied.


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.


Tetrahedron ◽  
1992 ◽  
Vol 48 (37) ◽  
pp. 8117-8126 ◽  
Author(s):  
Naji M. Ali ◽  
Alexander McKillop ◽  
Michael B. Mitchell ◽  
Ricardo A. Rebelo ◽  
Philip J. Wallbank

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