53578-01-1Relevant articles and documents
Conjugate addition of acetal-derived benzyl radicals generated from low-valent titanium-mediated CO bond cleavage
Suga, Takuya,Nakamura, Masaharu,Takada, Ryusei,Ukaji, Yutaka
supporting information, p. 1258 - 1260 (2021/05/17)
A new method for the generation of benzyl radicals from acetals via low-valent titanium-mediated homolytic CO bond cleavage is presented. The low cost and availability of the developed titanium reagent enable efficient access to α-alkoxy carbon radical species via the developed reaction.
Practical acetalization and transacetalization of carbonyl compounds catalyzed by recyclable PVP-I
Cao, Fu-Rong,Lu, Guangying,Ren, Jiangmeng,Wang, Di,Zeng, Bu-Bing
, (2021/06/21)
A novel PVP-I catalyzed acetalizations/transacetalizations of carbonyl compounds has been developed processing with a mild and easy handling fashion. Different types of Acyclic and cyclic acetals were prepared from carbonyl compounds or their acetals successfully. Further applications of newly developed catalytic combination were testified. This protocol featured with simplicity of operation, mild reaction condition, short reaction time, recyclable of catalyst and broad substrates scope with excellent yields.
Photocatalytic Reductive Formation of α-Tertiary Ethers from Ketals
Rossolini, Thomas,Ferko, Branislav,Dixon, Darren J.
supporting information, p. 6668 - 6673 (2019/09/03)
A general photocatalytic reductive strategy for the construction of unsymmetrical α-tertiary dialkyl ethers is reported. By merging Lewis acid-mediated ketal activation and visible-light photocatalytic reduction, in situ-generated α-alkoxy radicals were found to engage in addition reactions with a variety of olefinic partners. Good reaction efficiency is demonstrated with a range of ketals of aromatic and aliphatic ketones. Extension to acetal substrates is also described, demonstrating the overall synthetic utility of this methodology for complex ether synthesis.
Silver-Catalyzed Olefination of Acetals and Ketals with Diazoesters to β-Alkoxyacrylates
Li, Jiawen,Qian, Bo,Huang, Hanmin
supporting information, p. 7090 - 7094 (2018/11/23)
The first silver-catalyzed reaction of acetals or ketals with diazoesters leading to trisubstituted or tetrasubstituted β-alkoxyacrylates is now reported. A broad range of acetals and ketals bearing different substituents is compatible with this protocol and thus provides an attractive approach for the synthesis of complex β-alkoxyacrylates. The power of this method was further demonstrated by the successful synthesis of picoxystrobin, which is one of the most popular agricultural fungicides commercialized by Dupont.
Dual-gold(I)-generated trifluoromethylation of terminal alkynes with Togni's reagent
Siah, Huey-San Melanie,Fiksdahl, Anne
supporting information, p. 24 - 33 (2017/03/10)
The interaction of a Au(I) catalyst (JohnPhosAu(I)-MeCN/SbF6) and the Togni's reagent 1, as a source of electrophilic trifluoromethyl group, has been studied in order to develop gold-catalysed alkyne trifluoromethylation reactions. Alkyne-CF3products were prepared in moderate yields (up to 46%) by electrophilic trifluoromethylation of terminal arylalkynes with Togni's reagent 1 in the presence of sub-stoichiometric amounts of gold catalyst (25%). The proposed addition-elimination reaction mechanism proceeds through a Au-Togni Reagent complex with a linear Togni Reagent-O-Au(I)-P-(phosphane) coordination mode (X-ray analysis). Alkyne deprotonation gives rapid formation of protonated Togni Reagent and a σ,π-acetylide dual-Au complex, confirmed by X-ray analysis. It was shown that the σ,π-dual-Au complex activates for trifluoromethylation, most likely by transfer of a [LAu]+fragment to the alkyne substrate. The resulting reactive π-Au+-alkyne intermediate probably undergoes O-/CF3-addition of Togni Reagent, and final elimination of Togni alcohol gives the alkyne-CF3product.
Eco-friendly synthesis and antioxidant activity of new trifluoromethyl-substituted N-(pyrimidin-2-yl)benzo[d]thiazol-2-amines and some N-derivatives
Bonacorso, Helio G.,Calheiro, Tainara P.,Rodrigues, Melissa B.,Stefanello, Sílvio T.,Soares, Félix A. A.,Zanatta, Nilo,Martins, Marcos A. P.
, p. 2185 - 2194 (2016/11/17)
Abstract: A convenient and environmentally benign procedure for the synthesis of a new series of trifluoromethyl-substituted N-(pyrimidin-2-yl)benzo[d]thiazol-2-amines by the cyclocondensation reaction of (benzo[d]thiazolyl)guanidine with either 4-alkoxy-4-alkyl(aryl/heteroaryl)-1,1,1-trifluoroalk-3-en-2-ones or 2,2,2-trifluoro-1-(2-methoxycyclohexen-1-en-1-yl)ethanone is described. The main reactions were performed in refluxing water as the solvent (8–24?h), without catalysts, and the corresponding new N-(pyrimidinyl)-1H-(benzo[d]thiazolyl)amines were obtained at a 60–88?% yield. Subsequently, some di(hetero)arylamines were derivatized to the respective tertiary amines via easy N-alkylation and N-alkenylation reactions at 55–82?% yields. Finally, the Lipinski parameters and the total antioxidant activity of the new series of secondary arylamines were also evaluated. Graphical abstract: [Figure not available: see fulltext.]
Efficient syntheses of ethyl 2-methylthio-and ethyl 2-benzylthio-6-methyl(aryl)pyrimidine-4-carboxylates and their carboxylic acid derivatives
Zanatta, Nilo,Fortes, Andressa S.,Bencke, Carlos E.,Marangoni, Mário A.,Camargo, Adriano F.,Fantinel, Cassio A.,Bonacorso, Helio G.,Martins, Marcos A. P.
, p. 827 - 835 (2015/03/14)
A simple and efficient procedure for the synthesis of ethyl 2-methylthio-and ethyl 2-benzylthio-6-methyl(aryl)-pyrimidine-4-carboxylates and their corresponding acid derivatives is reported. The products are obtained in good yields via the cyclocondensation reaction of ethyl 4-alkoxy-2-oxo-4-methyl(aryl)-but-3-enoates with 2-methylisothiourea sulfate or 2-benzylisothiourea hydrochloride, under mild, basic, aqueous conditions.
Investigation of quantitative structure-reactivity relationships in the aliphatic Claisen rearrangement of bis-vinyl ethers reveals a dipolar, dissociative mechanism
O'Rourke, Natasha F.,Wulff, Jeremy E.
, p. 1292 - 1308 (2014/03/21)
Kinetic investigations of substituent effects in the thermal rearrangement of bis-vinyl ether substrates are reported. Findings indicate that the influence of the various substituent patterns on the rate of rearrangement in these compounds differs from that documented in the literature for the analogous [3,3]-sigmatropic rearrangement of allyl vinyl ethers. In addition, the thermochemical data collected suggests the existence of a dissociative transition state with significant dipolar character. These findings provide a unique contribution to the already extensive body of literature dedicated to mechanistic investigation of the Claisen rearrangement of aliphatic allyl vinyl ethers.
Anodic cleavage of several ketone N-phenylsemicarbazones into methyl N-phenylcarbamate and the corresponding dimethyl acetals
Nishikawa, Shinnosuke,Yamamori, Haruki,Ohashi, Kousuke,Okimoto, Mitsuhiro,Hoshi, Masayuki,Yoshida, Takashi
, p. 1766 - 1771 (2013/05/21)
Several ketone N-phenylsemicarbazones were electrooxidized in the presence of potassium iodide and a base using methanol as the solvent to give nearly commensurate amounts of methyl N-phenylcarbamate and the corresponding dimethyl acetals. Continuous evolution of gaseous nitrogen was observed from the anolyte during the electrooxidation. The reactions were carried out under very mild reaction conditions and are presumed to proceed through a four-electron oxidation process, in which the iodide ion plays an important role as an electron carrier.
A novel approach to the practical synthesis of sulfides: An InBr 3-Et3SiH catalytic system promoted the direct reductive sulfidation of acetais with disulfides
Sakai, Norio,Moritaka, Kohei,Konakahara, Takeo
supporting information; experimental part, p. 4123 - 4127 (2009/12/09)
We have demonstrated a facile and direct synthesis of sulfide derivatives using acetais and ketals, derived, from aromatic/ conjugated, aldehydes and aromatic ketones, with disulfides and the InBr3-Et3SiH reducing system., We also succeeded in developing an unprecedented one-pot preparation of an aliphatic sulfide from a disulfide and an aliphatic acetal. (Wiley-VCH Verlag GmbH & Co. KGaA.