2445-93-4Relevant articles and documents
Synergistic Relay Reactions To Achieve Redox-Neutral α-Alkylations of Olefinic Alcohols with Ruthenium(II) Catalysis
Kan, Jian,Li, Chao-Jun,Li, Chen-Chen,Li, Jianbin,Lv, Leiyang,Qiu, Zihang
supporting information, p. 4544 - 4549 (2020/02/04)
Herein, we report a ruthenium-catalyzed redox-neutral α-alkylation of unsaturated alcohols based on a synergistic relay process involving olefin isomerization (chain walking) and umpolung hydrazone addition, which takes advantage of the interaction between the two rather inefficient individual reaction steps to enable an efficient overall process. This transformation shows the compatibility of hydrazone-type “carbanions” and active protons in a one-pot reaction, and at the same time achieves the first Grignard-type nucleophilic addition using olefinic alcohols as latent carbonyl groups, providing a higher yield of the corresponding secondary alcohol than the classical hydrazone addition to aldehydes does. A broad scope of unsaturated alcohols and hydrazones, including some complex structures, can be successfully employed in this reaction, which shows the versatility of this approach and its suitability as an alternative, efficient means for the generation of secondary and tertiary alcohols.
Stabilization of cobalt catalysts by embedment for efficient production of valeric biofuel
Sun, Peng,Gao, Guang,Zhao, Zelun,Xia, Chungu,Li, Fuwei
, p. 4136 - 4142 (2015/02/19)
We herein report, for the first time, a bifunctional base-metal catalyst (Co@HZSM-5) that acts as an efficient alternative to noble-metal catalysts (e.g., Pt, Ru) for the conversion of levulinic acid into valeric biofuel under batch and fixed-bed reactor conditions. The cobalt nanoparticles were embedded in HZSM-5 crystals and catalyzed the sequential hydrogenations of the ketone and alkene functional groups; meanwhile, the acidic zeolite catalyzed the ring opening of the γ-valerolactone intermediate. Although base metals (e.g., Co) are abundant and inexpensive, their sintering and/or leaching under liquid-phase conditions always lead to the irreversible deactivation of the catalyst. In this system, the embedment structure stabilizes the nanoparticles, and Co@HZSM-5 could be used up to eight times. This work provides a practical clue toward the stabilization of base-metal catalysts and will inspire the development of large-scale biorefinery.
Radical mechanism in the elimination of 2-arylsulfinyl esters
Latorre, Antonio,Lopez, Irakusne,Ramirez, Victoria,Rodriguez, Santiago,Izquierdo, Javier,Gonzalez, Florenci V.,Vicent, Cristian
experimental part, p. 5191 - 5197 (2012/07/27)
The mechanism of the dehydrosulfenylation of 2-arylsulfinyl esters was investigated. The reaction was found to follow a homolytic cleavage mechanism as verified by electrospray ionization tandem mass spectrometry and experimental work. Rearranged sulfoxides are obtained as byproduct during the elimination reaction.
