92525-13-8Relevant academic research and scientific papers
Silylcarboxylic Acids as Bifunctional Reagents: Application in Palladium-Catalyzed External-CO-Free Carbonylative Cross-Coupling Reactions
Li, Xiong,Xu, Jie,Li, Yue,Kramer, S?ren,Skrydstrup, Troels,Lian, Zhong
supporting information, p. 4078 - 4083 (2020/07/30)
A palladium-catalyzed external-CO-free carbonylative Hiyama-Denmark cross-coupling reaction is presented. The introduction of silylcarboxylic acids as bifunctional reagents (CO and nucleophile source) avoids the need for external gaseous CO and a silylarene coupling partner. The transformation features high functional group tolerance and it is successful with electron-rich, -neutral, and -poor aryl iodides. Stoichiometric studies and control experiments provide insight into the reaction mechanism and support the hypothesized dual role of silylcarboxylic acids. (Figure presented.).
Palladium-catalyzed synthesis of diaryl ketones from aldehydes and (hetero)aryl halides via C-H bond activation
Wakaki, Takayuki,Togo, Takaya,Yoshidome, Daisuke,Kuninobu, Yoichiro,Kanai, Motomu
, p. 3123 - 3128 (2018/04/14)
We developed a palladium-catalyzed C-H transformation that enabled the synthesis of ketones from aldehydes and (hetero)aryl halides. The use of picolinamide ligands was key to achieving the transformation. Heteroaryl ketones, as well as diaryl ketones, were synthesized in good to excellent yields, even in gram-scale, using this reaction. Results of density functional theory (DFT) calculations support the C-H bond activation pathway.
Ni-Catalyzed cross-coupling reactions of N-acylpyrrole-type amides with organoboron reagents
Huang, Pei-Qiang,Chen, Hang
, p. 12584 - 12587 (2017/11/30)
The catalytic conversion of amides to ketones is highly desirable yet challenging in organic synthesis. We herein report the first Ni/bis-NHC-catalyzed cross-coupling of N-acylpyrrole-type amides with arylboronic esters to obtain diarylketones. This method is facilitated by a new chelating bis-NHC ligand. The reaction tolerates diverse functional groups on both arylamide and arylboronic ester partners including sensitive ester and ketone groups.
Regioselective Halo- and Carbodesilylation of (Trimethylsilyl)-1-methylpyrazoles
Effenberger, Franz,Krebs, Andreas
, p. 4687 - 4695 (2007/10/02)
The isomeric 3-, 4-, and 5-(trimethylsilyl)- as well as the 3,4-, 3,5-, and 4,5-bis(trimethylsilyl)-1-methylpyrazoles (2, 7, 3, 5, 9, and 10, respectively) are obtained by methylation of the corresponding (trimethylsilyl)-1H-pyrazoles or by silylation of Grignard or lithio derivatives of appropriate 1-methylpyrazoles with chlorotrimethylsilane. 5 and 10 are halodesilylated regioselectively by Br2 or ICl in the 4-position, yielding 13 and 15.With addditional bromine, these monobromo compounds suffer exclusively bromodesilylation to give 3,4- and 4,5-dibromo-1-methylpyrazole (14 and 16, respectively).These findings are in accord with the electrophilic substitution reactivity indices for 1-methylpyrazole (8) and with ipso-directing influence of the Me3Si group.The reaction of 5 with I2, unexpectedly, attacks preferentially at the 3-position.Regioselective carbodesilylation in the 5-position is observed in the fluoride-catalyzed reactions of 3, 9, and 10 with carbon electrophiles.The high regiospecificity of this reaction is rationalized in terms of carbanion stabilization at the individual pyrazole positions.
