55145-34-1Relevant academic research and scientific papers
Synthesis of Unsymmetrical N-Heterocyclic Carbene-Nitrogen-Phosphine Chelated Ruthenium(II) Complexes and Their Reactivity in Acceptorless Dehydrogenative Coupling of Alcohols to Esters
He, Xiaochun,Li, Yaqiu,Fu, Haiyan,Zheng, Xueli,Chen, Hua,Li, Ruixiang,Yu, Xiaojun
, p. 1750 - 1760 (2019/04/17)
Two novel ruthenium complexes RuH(CO)Cl(PPh3)(κ2-CP) (1) and [fac-RuH(CO)(PPh3)(κ3-CNP)]Cl (2) bearing unsymmetrical N-heterocyclic carbene-nitrogen-phosphine (CNP) were synthesized and characterized with 1H NMR, 31P NMR, and HRMS. The structure of complex 2 was further confirmed by single-crystal X-ray diffraction. An anion exchange experiment proved that complex 2 could transform into complex 1 in solution. The two complexes exhibited a highly catalytic performance in acceptorless dehydrogenative coupling of alcohols to esters, and the excellent isolated yields of esters were given in a catalyst loading of 1% for para- and meta-substituted benzyl alcohols and long-chain primary alcohols. Although some ortho-substituted benzyl alcohols displayed a relatively low reactivity due to the steric hindrance and the coordination of electron donor with the ruthenium center, the good product yields were still obtained by prolonging the reaction time. Especially, this system successfully realized the dehydrogenative cross-coupling to esters between two different primary alcohols.
Synthesis, Characterization, and unique catalytic activities of a fluorinated nickel enolate
Doi, Ryohei,Kikushima, Kotaro,Ohashi, Masato,Ogoshi, Sensuke
supporting information, p. 3276 - 3282 (2015/03/30)
We have synthesized a new nickel enolate [(PhCOCF2)Ni(dcpe)][FB(C6F5)3] featuring fluorine atoms on the enolate moiety via B(C6F5)3-promoted C-F bond activation of α,α,α-trifluoroacetophenone. X-ray diffraction study of [(PhCOCF2)Ni(dcpe)][FB(C6F5)3] revealed that the complex had adopted an η3-oxallyl coordination mode in the crystal lattice. The reaction of tBuNC with [(PhCOCF2)Ni(dcpe)][FB(C6F5)3] resulted in the coordination of isocyanide to the nickel center to form a C-bound enolate complex. The reactions of [(PhCOCF2)Ni(dcpe)][FB(C6F5)3] with aldehydes gave insertion products quantitatively which were fully characterized by NMR spectroscopy. Furthermore, we established unique catalytic applications for [(PhCOCF2)Ni(dcpe)][FB(C6F5)3] toward a Tishchenko reaction, along with a highly selective crossed-esterification of α,α,α-trifluoroacetophenones with aldehydes.
Nickel-catalyzed selective conversion of two different aldehydes to cross-coupled esters
Hoshimoto, Yoichi,Ohashi, Masato,Ogoshi, Sensuke
supporting information; experimental part, p. 4668 - 4671 (2011/05/16)
In the presence of a Ni(0)/NHC catalyst, an equimolar mixture of aliphatic and aryl aldehydes can be employed to selectively yield a single cross-coupled ester. This reaction can be applied to a variety of aliphatic (1°, 2°, cyc-2°, and 3°) and aryl aldehyde combinations. The reaction represents 100% atom efficiency and generates no waste. Mechanistic studies have revealed that the striking feature of the reaction is the simultaneous coordination of two aldehydes to Ni(0).
Oxone/sodium chloride: A simple and efficient catalytic system for the oxidation of alcohols to symmetric esters and ketones
Schulze, Agnes,Pagona, Georgia,Giannis, Athanassios
, p. 1147 - 1156 (2007/10/03)
An efficient method for the oxidation of alcohols is presented. The use of catalytic amounts of sodium chloride in combination with oxone allows the conversion primary aliphatic alcohols to symmetric esters. Secondary alcohols can be easily oxidized to ketones, and benzylic alcohols are converted to the corresponding aldehydes. The method is cost effective and enviromentally benign. Copyright Taylor & Francis Group, LLC.
Oxidation Using Quaternary Ammonium Polyhalides. III. An Effective Oxidation of Alcohols and Ethers by the Use of Benzyltrimethylammonium Tribromide
Kajigaeshi, Shoji,Kawamukai, Hiroshi,Fujisaki, Shizuo
, p. 2585 - 2588 (2007/10/02)
The reaction of primary alcohols or simple ethers and α,ω-diols or cyclic ethers with a stoichiometric amount of benzyltrimethylammonium tribromide (BTMA) Br3) in carbon tetrachloride in the presence of Na2HPO4 aq or in acetic acid in the presence of CH3CO2Na aq at 60-70 deg C gave dimeric esters and lactones respectively in good yields.The reaction of secondary alcohols with 1 equiv of BTMA Br3 in the presence of a buffer at 60 deg C gave ketones.
