19307-74-5Relevant academic research and scientific papers
Fine-tuning dirhodium compounds with bridging ligands: Synthesis, structure, catalytic efficiency
Ning, Yangbo,Tan, Jiantao,Wang, Yuanhua,Wang, Zhifan
supporting information, (2021/09/28)
The structure of dirhodium compounds contains a unique Rh-Rh bond, two axial ligands and four bridging ligands. In the dirhodium(II) compounds, it is easy to migrate the coordinating atoms of the bridging ligand during the catalysis process, which leads to the degradation of the catalyst. Coordination atom migration was identified in bridging ligands. To improve the catalyst stability, we carried out a study on the effect of fine-tuning of the bridging ligand on the dirhodium compound. Several dirhodium compounds were designed and synthesized. During this process, we have successfully found Rh2(5-Br-esp)2 and Rh2(5-tBu-esp)2, which are closer to the ideal geometric configuration of the dirhodium(II) compounds. Rh2(5-Br-esp)2 has been applied in the oxidation of propargyl position and Rh2(5-tBu-esp)2 in the formation reaction of the C–N bond.
Catalytic Ynone-Amidine Formal [4 + 2]-Cycloaddition for the Regioselective Synthesis of Tricyclic Azepines
Reddy, T. Prabhakar,Gujral, Jagjeet,Roy, Pritam,Ramachary, Dhevalapally B.
supporting information, p. 9653 - 9657 (2021/01/09)
A Ca(OTf)2- and self-promoted ynone-amidine atom-economic formal [4 + 2]-cycloaddition of various ynones with amidines is reported for the construction of highly functionalized tricyclic azepines. High reaction rate, ease of operation, and high product se
General Synthesis of α-Alkyl Ynones from Morpholine Amides and 1-Copper(I) Alkynes Promoted by Triflic Anhydride
Weng, Yunxiang,Min, Lin,Zeng, Xiaobao,Shan, Lidong,Wang, Xinyan,Hu, Yuefei
, p. 8296 - 8301 (2020/11/03)
The first general method for the synthesis of α-alkyl ynones was developed based on the strategy of electrophilic activation of amides. Its distinctive advantages are attributed to the use of air-stable "bare"1-copper(I) alkyne as a mild nucleophile witho
Fast and Efficient Continuous Flow Method for the Synthesis of Ynones and Pyrazoles
Kandasamy, Mohanraj,Ganesan, Balaji,Hung, Min-Yuan,Lin, Wei-Yu
supporting information, p. 3183 - 3189 (2019/05/28)
In this study, we developed a convenient and efficient two-step method for the synthesis of ynones in a flow reactor, through the generation of lithium acetylide and its subsequent reactions with acid chlorides. Using this approach, we obtained the ynones in moderate to good yields at room temperature. Moreover, we transformed the ynones into pyrazole derivatives through coupling with hydrazines. This transition metal-free process, mild reaction conditions, and broad functional group tolerance are all attractive features in comparison with conventional bench-top methods.
Use of the 2-Pyridinesulfonyloxy Leaving Group for the Fast Copper-Catalyzed Coupling Reaction at Secondary Alkyl Carbons with Grignard Reagents
Shinohara, Riku,Morita, Masao,Ogawa, Narihito,Kobayashi, Yuichi
supporting information, p. 3247 - 3251 (2019/05/10)
Investigation of the copper-catalyzed coupling reaction of 2-pyridinesulfonates with Grignard reagents revealed that reactions with catalytic Cu(OTf)2 were completed in 40 min. The results differed from those of the previous CuI-catalyzed reactions of tosylates in the presence of additives (LiOMe and TMEDA) for 12-24 h. It was shown that the preferred coordination of the leaving group to the reagents accelerated the reaction. Successful reagents were MeMgCl and other RMgX. Complete inversion was established.
Transition-metal-free C-C σ-bond activation of α-aryl ketones and subsequent Zn-catalyzed intramolecular cyclization: synthesis of tetrasubstituted furans
Yuan, Yang,Tan, Hailu,Kong, Lingkai,Zheng, Zhong,Xu, Murong,Huang, Jiaqi,Li, Yanzhong
, p. 2725 - 2733 (2019/03/12)
A highly atom-economical protocol for the synthesis of tetrasubstituted furans has been developed. This process is realized through the tandem reactions of Cs2CO3 promoted C-C σ-bond activation of α-aryl ketones followed by Zn-cataly
Phosphine-Catalyzed Intermolecular Annulations of Fluorinated ortho-Aminophenones with Alkynones – The Switchable [4+2] or [4+2]/[3+2] Cycloaddition
Zhang, Yanshun,Sun, Yaoliang,Wei, Yin,Shi, Min
supporting information, p. 2129 - 2135 (2019/03/13)
A phosphine-catalyzed intermolecular annulation reaction of functionalized ortho-aminoacetophenones with alkynones has been disclosed in this paper. A variety of 2-alkynylquinolines and benzo-fused indolizine were selectively afforded in moderate to good yields at different reaction temperatures and with different phosphine catalysts via the in situ generated zwitterionic intermediate derived from alkynone and phosphine. (Figure presented.).
Photocatalytic Annulation-Alkynyl Migration Strategy for Multiple Functionalization of Dual Unactivated Alkenes
Zhao, Qi,Hao, Wen-Juan,Shi, Hao-Nan,Xu, Ting,Tu, Shu-Jiang,Jiang, Bo
supporting information, p. 9784 - 9789 (2019/12/24)
A novel photoredox catalysis for multiple functionalization of two different types of unactivated alkenes in a single operation was reported through a conceptually new mode of annulation-alkynyl migration. A wide array of cyclopentane carboxylates were sy
Acyl Radicals from Benzothiazolines: Synthons for Alkylation, Alkenylation, and Alkynylation Reactions
Li, Lei,Guo, Shan,Wang, Qi,Zhu, Jin
supporting information, p. 5462 - 5466 (2019/08/01)
We describe herein a fundamentally new visible light-driven homolytic C-C bond breaking mode for the generation of acyl radicals from C2-acyl-substituted benzothiazolines. The reactive species can be used as versatile synthons for formal radical alkylatio
Merging " Anti-Baldwin" 3- Exo-Dig Cyclization with 1,2-Alkynyl Migration for Radical Alkylalkynylation of Unactivated Olefins
Zhao, Qi,Ji, Xiao-Shuang,Gao, Yi-Yun,Hao, Wen-Juan,Zhang, Ke-Ying,Tu, Shu-Jiang,Jiang, Bo
supporting information, p. 3596 - 3600 (2018/06/26)
A new combination of "anti-Baldwin" 3-exo-dig cyclization with 1,2-alkynyl migration of 1,4-enynes with simple cycloalkanes was established, enabling C-C breaking and reconstruction to access a wide range of α-alkynyl ketones with generally good yields by
