70959-98-7Relevant academic research and scientific papers
Synergistic Peptide and Gold Catalysis: Enantioselective Addition of Branched Aldehydes to Allenamides
Nicholls, Leo D. M.,Wennemers, Helma
supporting information, p. 17559 - 17564 (2021/10/19)
The combination of a peptide catalyst and a gold catalyst is presented for enantioselective addition reactions between branched aldehydes and allenamides. The two catalysts act in concert to provide γ,δ-enamide aldehydes bearing a fully substituted, benzylic stereogenic center – a structural motif common in many natural products and therapeutically active compounds – with good yields and enantioselectivities. The reaction tolerates a variety of alkyl and alkoxy substituted aldehydes and the products can be elaborated into several chiral building blocks bearing either 1,4- or 1,5- functional group relationships. Mechanistic studies showed that the conformational features of the peptide are important for both the catalytic efficiency and stereochemistry, while a balance of acid/base additives is key for ensuring formation of the desired product over undesired side reactions.
Facile synthesis of α-alkoxyl amides: Via scandium-catalyzed oxidative reaction between ynamides and alcohols
Zhang, Zhi-Xin,Zhu, Bo-Han,Xie, Pei-Xi,Tang, Jia-Qi,Li, Xin-Ling,Zhu, Chunyin,Yin, Ying-Wu,Ye, Long-Wu
, p. 18308 - 18315 (2018/05/30)
A novel and efficient scandium-catalyzed oxidative reaction between ynamides and alcohols for the facile synthesis of various α-alkoxyl amides is reported in this paper. The reaction avoids the need for the use of α-diazo carbonyls which are unstable and
Zirconium triflate grafted on SBA-15 as a highly efficient solid acid catalyst for ring opening of epoxides by amines and alcohols
Tayade, Kamlesh N.,Wang, Lianyue,Shang, Sensen,Dai, Wen,Mishra, Manish,Gao, Shuang
, p. 758 - 766 (2017/04/24)
Metal (Al, Ti, Zr) triflate grafted mesoporous SBA-15 (AlTf/S, TiTf/S, ZrTf/S) samples were synthesized as inexpensive solid acid materials by a simple one-pot-two-step synthesis methodology. These materials were characterized by X-ray diffraction, N2-sorption, thermogravimetric analysis, Fourier transform infrared spectroscopy (FT-IR), in-situ pyridine FT-IR spectroscopy, and elemental analysis. ZrTf/S was found to be a highly efficient and reusable solid acid catalyst for ring opening of epoxides with amines and alcohols and produced β-amino alcohols and β-alkoxy alcohols respectively under ambient reaction conditions. The ZrTf/S catalyst showed the highest activity, which was attributed to its high acidity compared with that of the Ti and Al containing samples.
Supported Tetrahedral Oxo-Sn Catalyst: Single Site, Two Modes of Catalysis
Beletskiy, Evgeny V.,Hou, Xianliang,Shen, Zhongliang,Gallagher, James R.,Miller, Jeffrey T.,Wu, Yuyang,Li, Tiehu,Kung, Mayfair C.,Kung, Harold H.
supporting information, p. 4294 - 4297 (2016/05/09)
Mild calcination in ozone of a (POSS)-Sn-(POSS) complex grafted on silica generated a heterogenized catalyst that mostly retained the tetrahedral coordination of its homogeneous precursor, as evidenced by spectroscopic characterizations using EXAFS, NMR, UV-vis, and DRIFT. The Sn centers are accessible and uniform and can be quantified by stoichiometric pyridine poisoning. This Sn-catalyst is active in hydride transfer reactions as a typical solid Lewis acid. However, the Sn centers can also create Br?nsted acidity with alcohol by binding the alcohol strongly as alkoxide and transferring the hydroxyl H to the neighboring Sn-O-Si bond. The resulting acidic silanol is active in epoxide ring opening and acetalization reactions.
Lanthanide-based coordination polymers as promising heterogeneous catalysts for ring-opening reactions
Kumar, Gulshan,Kumar, Girijesh,Gupta, Rajeev
, p. 21352 - 21361 (2016/03/08)
This work presents the synthesis and structural characterization of Eu3+- and Tb3+-based coordination polymers starting from a Co3+-based metalloligand offering appended arylcarboxylic acid groups. Both coordination polymers function as reusable heterogeneous catalysts for ring-opening reactions utilizing amines, alcohols, thiols, and azides as the nucleophiles. The catalytic results illustrate an excellent control over the regioselectivity whereas a filtration test and mechanistic studies substantiate Lewis-acid catalyzed activation of the epoxide during the reaction.
An epoxide ring-opening reaction by using sol–gel-synthesized palladium supported on a strontium hydroxyl fluoride catalyst
Acham, Vaibhav R.,Dongare, Mohan K.,Kemnitz, Erhard,Umbarkar, Shubhangi B.
, p. 1237 - 1246 (2016/10/13)
Palladium supported on a strontium hydroxyl fluoride catalyst was synthesized by a one-pot fluorolytic sol–gel method. The prepared catalyst was characterized by various physicochemical techniques. The sol–gel method has led to the formation of a high surface area (57?m2g?1), mesoporous (pore diameter?=?13.0?nm) catalyst with uniform dispersion of Pd nanoparticles of size ~7?nm on the surface of strontium hydroxyl fluoride. The catalyst was used for epoxide alcoholysis, and 100% conversion was obtained with 96% selectivity for β-alkoxy alcohols under mild conditions. The catalyst could be recycled for up to three catalytic cycles without any appreciable decrease in conversion and selectivity, indicating the stability of the catalyst under the reaction conditions. Further, the mechanism of alcoholysis was proposed on the basis of the physicochemical characteristics of the catalyst and on the basis of the products formed during the catalytic reaction.
An Iron(III) Catalyst with Unusually Broad Substrate Scope in Regioselective Alkylation of Diols and Polyols
Ren, Bo,Ramstr?m, Olof,Zhang, Qiang,Ge, Jiantao,Dong, Hai
, p. 2481 - 2486 (2016/02/12)
In this study, [Fe(dibm)3] (dibm=diisobutyrylmethane) is shown to have unusually broad scope as a catalyst for the selective monoalkylation of a diverse set of 1,2- and 1,3-diol-containing structures. The mechanism is proposed to proceed via a cyclic dioxolane-type intermediate, formed between the iron(III) species and two adjacent hydroxyl groups. This approach represents the first transition-metal catalysts that are able to replace stoichiometric amounts of organotin reagents in regioselective alkylation. The reactions generally lead to very high regioselectivities and high yields, on par with, or better than, previous methods used for regioselective alkylation.
Mild regiospecific alcoholysis and aminolysis of epoxides catalyzed by zirconium(IV) oxynitrate
Shinde, Sandip S.,Said, Madhukar S.,Surwase, Trupti B.,Kumar, Pradeep
supporting information, p. 5916 - 5919 (2015/11/02)
A regiospecific method for the ring-opening reaction of epoxides by the primary, secondary, tertiary alcohols, and aryl, aliphatic amines has been developed using non-toxic metal nitrate salt as a catalyst. The best results were obtained using zirconium(IV) oxynitrate among the various screened metal nitrate salts. The reported protocol works efficiently for styrene epoxide and aliphatic as well.
Graphite oxide: A simple and efficient solid acid catalyst for the ring-opening of epoxides by alcohols
Mirza-Aghayan, Maryam,Alizadeh, Mahdi,Molaee Tavana, Mahdieh,Boukherroub, Rabah
, p. 6694 - 6697 (2014/12/11)
A simple, efficient, and general procedure for the ring-opening of epoxides with various alcohols to give the corresponding β-alkoxy alcohols using graphite oxide (GO) as the catalyst, under very mild reaction conditions is described. The method proceeds in good to excellent yields and in short reaction times at room temperature under metal-free conditions.
Tetrahedral Sn-silsesquioxane: Synthesis, characterization and catalysis
Beletskiy, Evgeny V.,Shen, Zhongliang,Riofski, Mark V.,Hou, Xianliang,Gallagher, James R.,Miller, Jeffrey T.,Wu, Yuyang,Kung, Harold H.,Kung, Mayfair C.
supporting information, p. 15699 - 15701 (2015/02/19)
A tetrahedral stannasilsesquioxane complex was synthesized as a racemic mixture using Sn(OiPr)4 and silsesquioxanediol, and its structure was confirmed with X-ray crystallography, NMR, and EXAFS. The complex was a Lewis acid, and both anti and syn-binding with Lewis bases were possible with the formation of octahedral Sn complexes. It was also a Lewis acid catalyst active for epoxide ring opening and hydride transfer.
