959687-85-5Relevant articles and documents
Synthesis, structure, properties and antimicrobial activity of para trifluoromethyl phenylboronic derivatives
Adamczyk-Wo?niak, Agnieszka,Tarkowska, Magdalena,Lazar, Zofia,Kaczorowska, Ewa,Madura, Izabela D.,Maria D?browska, Anna,Lipok, Jacek,Wieczorek, Dorota
, (2021/12/23)
The [2-formyl-4-(trifluoromethyl)phenyl]boronic acid as well as its benzoxaborole and bis(benzoxaborole) derivatives were obtained and their properties studied. The 2-formyl compound displays an unusual structure in the crystalline state, with a significa
Sustainable Passerini-tetrazole three component reaction (PT-3CR): selective synthesis of oxaborol-tetrazoles
Singh, Akansha,Kumar, Ravindra
supporting information, p. 9708 - 9711 (2021/09/30)
A sustainable catalyst- and solvent-free Passerini-tetrazole three component reaction (PT-3CR) has been developed for the selective synthesis of benzoxaborol-tetrazoles for the first time. The synthetic potential of oxaboroles was demonstrated towards various functionalized tetrazoles, which are otherwise difficult to achieve through conventional PT-3CR from aromatic aldehydes/ketones. The reaction features high practicality, broad substrate scope and excellent yields (80-98%). Preliminary results of the asymmetric PT-3CR are also shown for the synthesis of chiral benzoxaboroles.
Catalytic Synthesis of 1 H-2-Benzoxocins: Cobalt(III)-Carbene Radical Approach to 8-Membered Heterocyclic Enol Ethers
De Bruin, Bas,De Zwart, Felix J.,Li, Zirui,Mathew, Simon,Wolzak, Lukas A.,Zhou, Minghui
supporting information, p. 20501 - 20512 (2021/12/03)
The metallo-radical activation of ortho-allylcarbonyl-aryl N-arylsulfonylhydrazones with the paramagnetic cobalt(II) porphyrin catalyst [CoII(TPP)] (TPP = tetraphenylporphyrin) provides an efficient and powerful method for the synthesis of novel 8-membered heterocyclic enol ethers. The synthetic protocol is versatile and practical and enables the synthesis of a wide range of unique 1H-2-benzoxocins in high yields. The catalytic cyclization reactions proceed with excellent chemoselectivities, have a high functional group tolerance, and provide several opportunities for the synthesis of new bioactive compounds. The reactions are shown to proceed via cobalt(III)-carbene radical intermediates, which are involved in intramolecular hydrogen transfer (HAT) from the allylic position to the carbene radical, followed by a near-barrierless radical rebound step in the coordination sphere of cobalt. The proposed mechanism is supported by experimental observations, density functional theory (DFT) calculations, and spin trapping experiments.
Nickel(0)-catalyzed intramolecular reductive coupling of alkenes and aldehydes or ketones with hydrosilanes
Hayashi, Yukari,Hoshimoto, Yoichi,Kumar, Ravindra,Ohashi, Masato,Ogoshi, Sensuke
supporting information, p. 6237 - 6240 (2016/05/19)
A nickel(0)-catalyzed reductive coupling of aldehydes and simple alkenes with hydrosilanes has been developed. A variety of silyl-protected 1-indanol derivatives were prepared in a highly diastereoselective manner (up to >99:1 dr) by employing a combination of nickel(0)/N-heterocyclic carbene and triethylsilane. The present system was also applied to a reductive coupling with ketones. Preliminary results of a nickel(0)-catalyzed asymmetric three-component coupling reaction of an aldehyde, an alkene, and triethylsilane are also shown.
Regiodivergent cyclobutanone cleavage: Switching selectivity with different Lewis acids
Souillart, Laetitia,Cramer, Nicolai
supporting information, p. 1863 - 1867 (2015/01/30)
The exploitation of strain release in small rings as driving force to enable complex transformations is a powerful synthetic tool. Among them, cyclobutanones are particularly versatile substrates that can be elaborated in a wide variety of structurally diverse building blocks. Herein, Lewis acid catalyzed rearrangement reactions are presented that provide selective access to two structurally distinct polycyclic scaffolds, that is, indenylacetic acid derivatives and benzoxabicyclo[3.2.1]octan-3-ones. The choice of the Lewis acid fully controls the reaction pathway and the regioselectivity of the cyclobutanone C-C bond cleavage site.
Highly enantioselective rhodium(I)-catalyzed carbonyl carboacylations initiated by C-C bond activation
Souillart, Laetitia,Cramer, Nicolai
supporting information, p. 9640 - 9644 (2014/11/27)
The lactone motif is ubiquitous in natural products and pharmaceuticals. The Tishchenko disproportionation of two aldehydes, a carbonyl hydroacylation, is an efficient and atom-economic access to lactones. However, these reaction types are limited to the transfer of a hydride to the accepting carbonyl group. The transfer of alkyl groups enabling the formation of C-C bonds during the ester formation would be of significant interest. Reported herein is such asymmetric carbonyl carboacylation of aldehydes and ketones, thus affording complex bicyclic lactones in excellent enantioselectivities. The rhodium(I)-catalyzed transformation is induced by an enantiotopic C-C bond activation of a cyclobutanone and the formed rhodacyclic intermediate reacts with aldehyde or ketone groups to give highly functionalized lactones. Delivering the goods: Asymmetric carbonyl carboacylations of aldehydes and ketones provide access to functionalized bicyclic lactones. The rhodium(I)-catalyzed transformation is induced by an enantiotopic C-C bond activation of a cyclobutanone and the transient rhodacyclic adds across an appended carbonyl group to deliver the lactones in excellent enantioselectivities.
Highly efficient activation of organosilanes with η2-aldehyde nickel complexes: Key for catalytic syntheses of aryl-, vinyl-, and alkynyl-benzoxasiloles
Hoshimoto, Yoichi,Yabuki, Hayato,Kumar, Ravindra,Suzuki, Haruka,Ohashi, Masato,Ogoshi, Sensuke
supporting information, p. 16752 - 16755 (2015/01/16)
An η2-aldehyde nickel complex was utilized as an effective activator for an organosilane in order to generate a hypervalent silicate reactant for the first time. This method was successfully applied to the highly efficient syntheses of 3-aryl-, vinyl-, and alkynyl-2,1-benzoxasiloles from benzaldehydes with aryl-, vinyl-, and alkynylsilyl groups at the ortho position. Initial mechanistic studies revealed that an intermolecular aryl transfer process was involved in the reaction mechanism. The formation of an η2-aldehyde complex was directly confirmed by NMR.
