50555-04-9Relevant academic research and scientific papers
Regioselective Wacker-Type Oxidation of Internal Olefins in tBuOH Using Oxygen as the Sole Oxidant and tBuONO as the Organic Redox Cocatalyst
Huang, Qing,Li, Ya-Wei,Ning, Xiao-Shan,Jiang, Guo-Qing,Zhang, Xiao-Wei,Qu, Jian-Ping,Kang, Yan-Biao
supporting information, p. 965 - 969 (2020/02/15)
A regioselective Wacker-Tsuji oxidation of internal olefins in tBuOH has been developed using oxygen as the terminal oxidant and tert-butyl nitrite as the simple organic redox cocatalyst without the involvement of hazardous cocatalysts or harsh reaction conditions. A series of internal olefins bearing various functional groups can be oxidized to the corresponding substituted ketones in generally good yields with high regioselectivities.
Aerobic Acyloxylation of Allylic C?H Bonds Initiated by a Pd0 Precatalyst with 4,5-Diazafluoren-9-one as an Ancillary Ligand
Kozack, Caitlin V.,Sowin, Jennifer A.,Jaworski, Jonathan N.,Iosub, Andrei V.,Stahl, Shannon S.
, p. 3003 - 3007 (2019/06/17)
Palladium-catalyzed allylic C?H oxidation has been widely studied, but most precedents use acetic acid as the coupling partner. In this study, a method compatible with diverse carboxylic acid partners has been developed. Use of a Pd0 precatalyst under aerobic reaction conditions leads to oxidation of Pd0 by O2 in the presence of the desired carboxylic acid to generate a PdII dicarboxylate that promotes acyloxylation of the allylic C?H bond. Good-to-excellent yields are obtained with a roughly 1:1 ratio of the alkene and carboxylic acid reagents. Optimized reaction conditions employ 4,5-diazafluoren-9-one (DAF) as a ligand, in combination with a quinone/iron phthalocyanine cocatalyst system to support aerobic catalytic turnover.
Systematic Evaluation of Sulfoxides as Catalysts in Nucleophilic Substitutions of Alcohols
Motsch, Sebastian,Schütz, Christian,Huy, Peter H.
supporting information, p. 4541 - 4547 (2018/09/13)
Herein, a method for the nucleophilic substitution (SN) of benzyl alcohols yielding chloro alkanes is introduced that relies on aromatic sulfoxides as Lewis base catalysts (down to 1.5 mol-%) and benzoyl chloride (BzCl) as reagent. A systematic screening of various sulfoxides and other sulfinyl containing Lewis bases afforded (2-methoxyphenyl)methyl sulfoxide as optimal catalyst. In contrast to reported formamide catalysts, sulfoxides also enable the application of plain acetyl chloride (AcCl) as reagent. In addition, it was demonstrated that weakly electrophilic carboxylic acid chlorides like BzCl promote Pummerer rearrangement of sulfoxides already at room temperature. This side-reaction also provided the explanation, why sulfoxide catalyzed SN-reactions of alcohols do not allow the effective production of aliphatic and electron deficient chloro alkanes. Comparison experiments provided further insight into the reaction mechanism.
Iridium-Catalyzed Enantioselective Allylic Substitution of Aliphatic Esters with Silyl Ketene Acetals as the Ester Enolates
Jiang, Xingyu,Hartwig, John F.
supporting information, p. 8887 - 8891 (2017/07/17)
Enantioselective allylic substitution with enolates derived from aliphatic esters under mild conditions remains challenging. Herein we report iridium-catalyzed enantioselective allylation reactions of silyl ketene acetals, the silicon enolates of esters, to form products containing a quaternary carbon atom at the nucleophile moiety and a tertiary carbon atom at the electrophile moiety. Under relatively neutral conditions, the allylated aliphatic esters were obtained with excellent regioselectivity and enantioselectivity. These products were readily converted into primary alcohols, carboxylic acids, amides, isocyanates, and carbamates, as well as tetrahydrofuran and γ-butyrolactone derivatives, without erosion of enantiomeric purity.
Transition-Metal-Free Poly(thiazolium) Iodide/1,8-Diazabicyclo[5.4.0]undec-7-ene/Phenazine-Catalyzed Esterification of Aldehydes with Alcohols
Chun, Supill,Chung, Young Keun
supporting information, p. 3787 - 3790 (2017/07/26)
Poly(3,4-dimethyl-5-vinylthiazolium) iodide was used as a polymer precatalyst in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and phenazine for the oxidative esterification of aldehydes with alcohols. Selective functionalization of OH groups was achieved in the presence of NH2 groups. The poly(thiazolium) iodide/DBU/phenazine system exhibited excellent catalytic activity and could be reused five times without loss of activity.
Highly efficient nitrogen chelated ruthenium carbene metathesis catalysts
Duan, Yulian,Wang, Tao,Xie, Qingxiao,Yu, Xiaobo,Guo, Weijie,Wang, Jianhui,Liu, Guiyan
, p. 19441 - 19448 (2016/12/16)
A series of nitrogen chelated ruthenium carbene metathesis catalysts containing an N-heterocyclic carbene (NHC) and a carbonyl group have been developed and their catalytic activities for olefin metathesis reactions were investigated. The X-ray structure of the [(H2IMes)(Cl)2Ru]C(H)CH2[p-F(C6H3)NC(CF3)(C(O)OCH2CH3)] complex shows that the carbonyl oxygen of the ester and the imine nitrogen are both coordinated to the Ru metal to give an octahedral structure. The catalytic activity of these ruthenium carbene complexes for olefin metathesis reactions was tested. Some of the complexes bearing electron withdrawing groups had high initiation rates. These complexes exhibited excellent performance for both ring-closing metathesis and cross metathesis.
METHOD OF CONVERTING ALCOHOL TO HALIDE
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Page/Page column 50; 107; 108, (2017/01/02)
The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
A six-coordinated cationic ruthenium carbyne complex with liable pyridine ligands: Synthesis, structure, catalytic investigation, and DFT study on initiation mechanism
Liu, Guiyan,Zheng, Lu,Shao, Mingbo,Zhang, Huizhu,Qiao, Weixia,Wang, Xiaojia,Liu, Bowen,Zhao, Haitao,Wang, Jianhui
supporting information, p. 4718 - 4725 (2014/06/24)
A novel six-coordinated high-valence cationic ruthenium carbyne complex bearing two liable pyridine ligands was prepared in high yield by the reaction of the ruthenium-based complex (IMesH2)(Cl)2(C 5H5N)2RuCHPh [IMesH2=1,3-dimesityl- 4,5-dihydroimida-zol-2-ylidene] with excess iodine as an oxidant in CH 2Cl2 at 25 °C under N2. The new ruthenium carbyne-based complex shows moderate to good catalytic activity for ring-closing metathesis reactions. Importantly, no double bond isomerization by-product was produced at elevated reaction temperatures (100 °C-137 °C) in the reaction catalyzed by the synthesized ruthenium carbyne complex. A mechanism involving the in situ conversion of the ruthenium carbyne through the addition of an iodide to the carbyne carbon was also proposed, and DFT calculations were performed to explain the initiating mechanism.
Modified Yamaguchi reagent: Convenient and efficient esterification
Okuno, Yoshinori,Isomura, Shigeki,Nishibayashi, Akihiro,Hosoi, Aiko,Fukuyama, Kei,Ohba, Masashi,Takeda, Kazuyoshi
supporting information, p. 2854 - 2860 (2014/10/15)
A convenient and efficient esterification method that used a modified Yamaguchi reagent (2,4,6-trichlorobenzoyl chloride-4-dimethylaminopyridine) and avoided use not only of intractable acid chloride but also of acid anhydrides was proposed. The reaction mechanism was described by Fourier transform infrared spectroscopy and supported by a density functional theory calculation.
Synthesis of acyclic ketones by catalytic, bidirectional homologation of formaldehyde with nonstabilized diazoalkanes. Application of a chiral diazomethyl(pyrrolidine) in total syntheses of erythroxylon alkaloids
Wommack, Andrew J.,Kingsbury, Jason S.
, p. 10573 - 10587 (2013/11/19)
This work offers a catalytic approach to convergent ketone assembly based upon formal and tandem C-H insertion of diazoalkanes in the presence of limiting amounts of monomeric formaldehyde, which is easily generated as a gas by thermolysis of the inexpensive and abundant paraformaldehyde (～30 USD/kg). The method forms di-, tri-, and even tetrasubstituted acetones with high efficiency, and it has streamlined a synthesis of (-)-dihydrocuscohygrine in which the absolute stereochemistry of a proline-based starting material is preserved. Assisted by the advent of new protocols for hydrazone oxidation, we also provide full details on handling non-carbonyl-stabilized diazo compounds.
