27331-33-5Relevant articles and documents
Synthesis, C-H bond functionalisation and cycloadditions of 6-styryl-1,2-oxathiine 2,2-dioxides
Gabbutt, Christopher D.,Heron, B. Mark,Lilly, Thomas,Ogwang, Ochola W.,Zonidis, Dimitrios
, p. 6431 - 6446 (2021)
A series of 6-styryl-1,2-oxathiine 2,2-dioxides have been efficiently obtained by a two-step protocol from readily available (1E,4E)-1-(dimethylamino)-5-arylpenta-1,4-dien-3-ones involving a regioselective sulfene addition and subsequent Cope elimination. Pd-Mediated direct C-H bond functionalisation of the 6-styryl-1,2-oxathiine 2,2-dioxides and a wider selection of 5,6-diaryl substituted 1,2-oxathiine 2,2-dioxides proceeded smoothly to afford C-3 (hetero)aryl substituted analogues and the results are contrasted with those of a complementary bromination - Suzuki cross-coupling sequence. Whilst the cycloaddition of benzyne, derived fromin situfluoride initiated decomposition of 2-(trimethylsilyl)phenyl trifluoromethanesulfonate, to the substituted 1,2-oxathiine 2,2-dioxides resulted in low yields of substituted naphthalenes, the addition of 4-phenyl-1,2,4-triazoline-3,5-dione to the 6-styryl-1,2-oxathiine 2,2-dioxides afforded novel 5,9-dihydro-1H-[1,2]oxathiino[5,6-c][1,2,4]triazolo[1,2-a]pyridazine-1,3(2H)-dione 8,8-dioxides through a silica-mediated isomerisation of the initial [4 + 2] adducts.
Aryl Fluoride Activation through Palladium-Magnesium Bimetallic Cooperation: A Mechanistic and Computational Study
Wu, Chen,McCollom, Samuel P.,Zheng, Zhipeng,Zhang, Jiadi,Sha, Sheng-Chun,Li, Minyan,Walsh, Patrick J.,Tomson, Neil C.
, p. 7934 - 7944 (2020)
Herein is described a mechanistic study of a palladium-catalyzed cross-coupling of aryl Grignard reagents to fluoroarenes that proceeds via a low-energy heterobimetallic oxidative addition pathway. Traditional oxidative additions of aryl chlorides to Pd complexes are known to be orders of magnitude faster than with aryl fluorides, and many palladium catalysts do not activate aryl fluorides at all. The experimental and computational studies outlined herein, however, support the view that at elevated Grignard/ArX ratios (i.e., 2.5:1), a Pd-Mg heterobimetallic mechanism predominates, leading to a remarkable decrease in the energy required for Ar-F bond activation. The heterobimetallic transition state for the C-X bond cleavage is proposed to involve simultaneous Pd backbonding to the arene and Lewis acid activation of the halide by Mg to create a low-energy transition state for oxidative addition. The insights gained from this computational study led to the development of a phosphine ligand that was shown to be similarly competent for Ar-F bond activation.
Iron-Catalyzed Cross-Coupling Reactions of Arylmagnesium Reagents with Aryl Chlorides and Tosylates: Influence of Ligand Structural Parameters and Identification of a General N-Heterocyclic Carbene Ligand
Wu, Wenqin,Teng, Qiaoqiao,Chua, Yi-Yuan,Huynh, Han Vinh,Duong, Hung A.
, p. 2293 - 2297 (2017)
A systematic evaluation of N-heterocyclic carbene ligands in the iron-catalyzed cross-coupling reactions of aryl chlorides and arylmagnesium reagents is performed. There is no clear correlation between the donor strength of the N-heterocyclic carbene and the reaction outcome. Instead, the highest yields of the desired biaryl product are obtained with sterically demanding ligands possessing large %Vbur values. Through this study, SIPrNap has been identified as an efficient and general ligand for the coupling of both aryl chlorides and tosylates.
Construction of Bulky Ligand Libraries by Ru(II)-Catalyzed P(III)-Assisted ortho-C-H Secondary Alkylation
Li, Jia-Wei,Li, Ming,Liu, Yue-Jin,Tao, Jun-Yang,Wang, Liang-Neng,Zeng, Ming-Hua
supporting information, p. 11915 - 11925 (2021/09/13)
Modification of commercially available biaryl monophosphine ligands via ruthenium(II)-catalyzed P(III)-directed-catalyzed ortho C-H secondary alkylation is described. The use of highly ring-strained norbornene as a secondary alkylating reagent is the key to this transformation. A series of highly bulky ligands with a norbornyl group were obtained in excellent yields. The modified ligands with secondary alkyl group outperformed common substituted phosphines in the Suzuki-Miyaura cross-coupling reaction at a ppm mole level of Pd catalyst.
Continuous slurry plug flow Fe/ppm Pd nanoparticle-catalyzed Suzuki-Miyaura couplings in water utilizing novel solid handling equipment
Chang, Jim,Gallou, Fabrice,Lipshutz, Bruce H.,Plummer, Scott,Robinson, Richard I.,Smith, Marie,Wood, Alex B.
supporting information, p. 7724 - 7730 (2021/10/12)
Herein are reported initial efforts to develop a generally accessible flow process, applying a heterogenous nanocatalyst to aqueous micelle-enabled Suzuki-Miyaura coupling reactions. Also disclosed is a new engineering solution (i.e., a self-draining back pressure regulator), which, when applied, enabled 1.5 hours of continuous operation leading to the production of 20 grams of a pharmaceutical intermediate.
