57699-45-3Relevant academic research and scientific papers
Zn- And Cu-catalyzed coupling of tertiary alkyl bromides and oxalates to forge challenging C?O, C?S, and C?N bonds
Gong, Yuxin,Zhu, Zhaodong,Qian, Qun,Tong, Weiqi,Gong, Hegui
supporting information, p. 1005 - 1010 (2021/02/01)
We describe here the facile construction of sterically hindered tertiary alkyl ethers and thioethers via the Zn(OTf)2catalyzed coupling of alcohols/phenols with unactivated tertiary alkyl bromides and the Cu(OTf)2-catalyzed thiolation of unactivated tertiary alkyl oxalates with thiols. The present protocol represents one of the most effective unactivated tertiary C(sp3)? heteroatom bond-forming conditions via readily accessible Lewis acid catalysis that is surprisingly less developed.
Encapsulation of Flavin Cofactor within a Manganese Porphyrin-Based Metal-Organic Polyhedron for Reductive Dioxygen Activation
Guo, Huimin,He, Cheng,Li, LiLi,Li, Xuezhao,Wang, Hailing,Yang, Linlin
supporting information, p. 2636 - 2640 (2020/03/19)
Encapsulation of flavin mononucleotide (FMN) in a porphyrinatomanganese(III)-based cubic cage allowed the fast reduction of manganese(III) porphyrin in the presence of nicotinamide adenine dinucleotide (NADH). This supramolecular system was capable of efficiently activating dioxygen and catalyzing the oxidation of benzyl alcohol. Control experiments suggested that the close proximity between FMN and manganese(III) porphyrins forced by the host-guest interaction might benefit the electron-transfer process from the FMN cofactor to the metal centers.
Visible-Light-Promoted Nickel- and Organic-Dye-Cocatalyzed Formylation Reaction of Aryl Halides and Triflates and Vinyl Bromides with Diethoxyacetic Acid as a Formyl Equivalent
Huang, He,Li, Xiangmin,Yu, Chenguang,Zhang, Yueteng,Mariano, Patrick S.,Wang, Wei
supporting information, p. 1500 - 1505 (2017/02/05)
A simple formylation reaction of aryl halides, aryl triflates, and vinyl bromides under synergistic nickel- and organic-dye-mediated photoredox catalysis is reported. Distinct from widely used palladium-catalyzed formylation processes, this reaction proceeds by a two-step mechanistic sequence involving initial in situ generation of the diethoxymethyl radical from diethoxyacetic acid by a 4CzIPN-mediated photoredox reaction. The formyl-radical equivalent then undergoes nickel-catalyzed substitution reactions with aryl halides and triflates and vinyl bromides to form the corresponding aldehyde products. Significantly, besides aryl bromides, less reactive aryl chlorides and triflates and vinyl halides serve as effective substrates for this process. Since the mild conditions involved in this reaction tolerate a plethora of functional groups, the process can be applied to the efficient preparation of diverse aromatic aldehydes.
Alcohols and di-tert-butyl dicarbonate: How the nature of the Lewis acid catalyst may address the reaction to the synthesis of tert-butyl ethers
Bartoli, Giuseppe,Bosco, Marcella,Carlone, Armando,Dalpozzo, Renato,Locatelli, Manuela,Melchiorre, Paolo,Sambri, Letizia
, p. 9580 - 9588 (2007/10/03)
The reaction between alcohols and Boc2O leads to the formation of ferf-butyl ethers and/or Boc-alcohols, depending on the nature of the Lewis acid catalyst. Product distribution is mainly tuned by the anionic part of the salt. Perchlorates and Inflates, anions with highly delocalized negative charge, give prevalent or exclusive ether formation. On the other hand, Boc alcohols are the main or exclusive products with un-delocalized isopropoxide or low-delocalized acetate ions. The metal ion influences only the reaction rate, roughly following standard parameters for calculating Lewis acidity. A reaction mechanism is supposed, and a series of experimental evidences is reported to support it. These studies allowed us to conclude that, to synthesize tert-butyl ethers, in reactions involving aliphatic alcohols, Mg(ClO4) 2 or Al(ClO4)3 represents the best compromise between costs and efficiency of the reaction, while, in reactions involving phenols, Sc(OTf)3 is the best choice, since aromatic tert-butyl ethers are not stable in the presence of perchlorates.
Oxoammonium resins as metal-free, highly reactive, versatile polymeric oxidation reagents
Weik, Steffen,Nicholson, Graeme,Jung, Gnther,Rademann, Jrg
, p. 1436 - 1439 (2007/10/03)
Polymer-supported oxidation of alcohols was conducted very efficiently by employing oxoammonium salts, the reactive intermediates in TEMPO oxidations (TEMPO = 2,2,6,6-tetramethylpiperidinoxyl). These highly reactive salts (see scheme; X = Br, C1) could be prepared and isolated on the polymeric support, and were used for the conversion of single compounds as well as of complex mixtures of alcohols.
Oxidizing polymers: A polymer-supported, recyclable hypervalent iodine(V) reagent for the efficient conversion of alcohols, carbonyl compounds, and unsaturated carbamates in solution
Sorg,Mengel,Jung,Rademann
, p. 4395 - 4397 (2007/10/03)
The oxidation of various alcohols and cyclization of an olefinic carbamate succeeds with the first polymer-supported iodine(v) reagent (see scheme). The novel oxidizing polymer oxidizes sensitive and complex alcohols, including protected amino alcohols, efficiency in good excellent yields. In addition, the α,β-dehydration of a ketone is demonstrated.
Protection of phenols as t-butyl ethers under mild conditions
Bandgar,Kasture
, p. 252 - 253 (2007/10/03)
Zinc mediated selective O-y-butylation of phenols has been carried out in good to excellent yields under mild conditions. No trace of C-t-butylation was observed.
Palladium/P(t-Bu)3-catalyzed synthesis of aryl t-butyl ethers and application to the first synthesis of 4-chlorobenzofuran
Watanabe, Makoto,Nishiyama, Masakazu,Koie, Yasuyuki
, p. 8837 - 8840 (2007/10/03)
Pd/P(t-Bu)3 catalyzed reaction of aryl halides with sodium t-butoxide effectively to give aryl t-butyl ethers. The high catalytic activity realized the formation of aryl t-butyl ethers from not only electron-deficient aryl halides but also electron-rich aryl halides. Moreover, the first synthesis of 4-chlorobenzofuran was attained utilizing the selective mono-t-butoxylation of aryl dihalide.
Aromatic nucleophilic substitutions under microwave irradiation
Salmoria, Gean V.,Dall'Oglio, Evandro,Zucco, Cesar
, p. 2471 - 2474 (2007/10/03)
In order to study the effect of microwave irradiation over aromatic nucleophilic substitutions at atmospheric pressure and in a homogeneous medium, experiments with disubstituted-benzenes and the nucleophiles piperidine and potassium t-butoxide, in refluxing DMSO or DMF, were carried out. The aromatic nucleophilic substitutions under microwave irradiation were 2.7 to 12 times faster than under conventional reflux.
Synthesis, structure and stability of E/Z-isomers of novel conjugated enamines prepared from 9-arylmethyl- or 9-arylpropenyl-9H-carbazole with arylmethyleneanilines
Paventi, Martino,Hay, Allan S.
, p. 1059 - 1068 (2007/10/03)
Active methylene groups, substituted by 9H-carbazol-9-yl (Carb) and aryl or 2-phenylethenyl groups, condense with arylmethyleneanilines in DMF at 75°C in the presence of Bu'OK to form the corresponding enamines [(Carb)(Ar1)C=C(Ar2)H] and dienamines [(Ar3)HC=C(Carb)CH=CHPh] in almost quantitative yield. The 1H and 13C NMR spectra for the enamine 1′Z-isomers [16 (Ar1 = Ar2 = 4-fluorophenyl), 17 (Ar1 = 4-fluorophenyl, Ar2 = 4-tert-butoxyphenyl), 19 (Ar1 = Ar2 = 4-tert-butoxyphenyl)], dienamine 1′Z-isomers [14a (Ar3 = 1-naphthyl), 14b (Ar3 = 4-methoxyphenyl), 14c (Ar3 = Ph)] and 1′E-isomers [15a (Ar3 = 1-naphthyl), 15c (Ar3 = Ph)] and precursors are assigned with the aid of COSY, HMBC, and HMQC techniques. The geometrical isomerism of the different dienamines 14-15 is established by 3JC-H NMR couplings and that of enamine 12 by a difference NOE experiment. X-Ray crystal structures for 16, 14a and 15c corroborate the isomerism results deduced by NMR studies. Dienamines 14a and 15a hydrolyse to the ketone under relatively strong acid conditions [AcOH-HCl-H2O (18:1:1 v/v)] under reflux over 7 h. There is an equilibrium between 14c and 15c in 1,2,4-trichlorobenzene at 180 ± 1°C with K = 15c/14c = 0.77 as estimated from the kinetic rate profiles from HPLC data acquired over 4 days. However, under the same conditions, 14a and 15a undergo an equilibration concurrent with a reaction (monitored over 9 days) giving apparently a carbazolyl-substituted phenylphenanthrene. In contrast, enamine 16 is thermally stable with no detectable change after boiling for 4 days in 1,2,4-trichlorobenzene.
