20401-88-1Relevant articles and documents
Conjugate addition of electron-rich aromatics to acrolein in the confined space of zeolite Y
Imachi, Shouhei,Onaka, Makoto
, p. 708 - 709 (2005)
Acrolein gas was spontaneously entrapped in supercages of NaY zeolite and the sorption was confirmed by solid 13C MAS NMR spectra. In the confined cavities, acrolein smoothly underwent conjugate addition with electron-rich aromatics such as ind
Magnetic nanoparticles as a catalyst vehicle for simple and easy recycling
Yoon, Tae-Jong,Lee, Woo,Oh, Yoon-Seuk,Lee, Jin-Kyu
, p. 227 - 229 (2003)
The surface of magnetic ferrite nanoparticles (CoFe2O4) was coated with a Rh-based cationic complex, [Rh(cod)(η6-benzoic acid)]BF4, to make them homogeneously dispersable and thermodynamically stable without an
Complex Polyheterocycles and the Stereochemical Reassignment of Pileamartine A via Aza-Heck Triggered Aryl C-H Functionalization Cascades
Bower, John F.,Caiger, Lewis,García-Cárceles, Javier,Hazelden, Ian R.,Jones, Benjamin T.,Langer, Thomas,Lewis, Richard J.
supporting information, p. 15593 - 15598 (2021/10/12)
Structurally complex benzo- and spiro-fused N-polyheterocycles can be accessed via intramolecular Pd(0)-catalyzed alkene 1,2-aminoarylation reactions. The method uses N-(pentafluorobenzoyloxy)carbamates as the initiating motif, and this allows aza-Heck-type alkene amino-palladation in advance of C-H palladation of the aromatic component. The chemistry is showcased in the first total synthesis of the complex alkaloid (+)-pileamartine A, which has resulted in the reassignment of its absolute stereochemistry.
Catalytic δ-hydroxyalkynone rearrangement in the stereoselective total synthesis of centrolobine, engelheptanoxides A and C and analogues
Ahmad, Mohammad N.,Chopra, Sidharth,Fernandes, Rodney A.,Kumar, Praveen
, (2021/08/13)
A catalytic stereoselective total synthesis of centrolobine and engelheptanoxides A and C has been completed via a metal-free catalytic δ-hydroxyalkynone rearrangement to 2,3-dihydro-4H-pyran-4-one and diastereoselective hydrogenation to the all syn-2,4,6-trisubstituted pyran strategy. The onliest required chirality was introduced by Jacobsen kinetic resolution, which further directed the diastereoselective hydrogenation. A first stereoselective synthesis of engelheptanoxide A is also accomplished. The analogues and derivatives of centrolobine and engelheptanoxides prepared were evaluated for antitubercular activity against M. tuberculosis H37Rv ATCC 27294.
Chemo- And regioselective hydroformylation of alkenes with CO2/H2over a bifunctional catalyst
Hua, Kaimin,Liu, Xiaofang,Wei, Baiyin,Shao, Zilong,Deng, Yuchao,Zhong, Liangshu,Wang, Hui,Sun, Yuhan
supporting information, p. 8040 - 8046 (2021/11/01)
As is well known, CO2 is an attractive renewable C1 resource and H2 is a cheap and clean reductant. Combining CO2 and H2 to prepare building blocks for high-value-added products is an attractive yet challenging topic in green chemistry. A general and selective rhodium-catalyzed hydroformylation of alkenes using CO2/H2 as a syngas surrogate is described here. With this protocol, the desired aldehydes can be obtained in up to 97% yield with 93/7 regioselectivity under mild reaction conditions (25 bar and 80 °C). The key to success is the use of a bifunctional Rh/PTA catalyst (PTA: 1,3,5-triaza-7-phosphaadamantane), which facilitates both CO2 hydrogenation and hydroformylation. Notably, monodentate PTA exhibited better activity and regioselectivity than common bidentate ligands, which might be ascribed to its built-in basic site and tris-chelated mode. Mechanistic studies indicate that the transformation proceeds through cascade steps, involving free HCOOH production through CO2 hydrogenation, fast release of CO, and rhodium-catalyzed conventional hydroformylation. Moreover, the unconventional hydroformylation pathway, in which HCOOAc acts as a direct C1 source, has also been proved to be feasible with superior regioselectivity to that of the CO pathway.
