Gold-Catalyzed Cyclization and Subsequent Arylidene Group Transfer of O-Propioloyl Oximes
摘要:
Gold-catalyzed cyclizations of O-propioloyl oximes via C-N bond formation followed by arylidene group transfer were successfully carried out to afford the corresponding 4-arylideneisoxazol-5(4H)-ones in good to excellent yields. As an example, (E)-benzaldehyde O-3-phenylpropioloyl oxime (1a) was reacted in acetonitrile at 25 degrees C in the presence of Au(PPh(3))NTf(2) (5 mol %) to give 4-benzylidene-3-phenylisoxazol-5(4H)-one (2a) in 90% yield. On the basis of crossover experiments, the arylidene "migration" was shown to proceed in an intermolecular manner.
An Aminocatalyzed Stereoselective Strategy for the Formal α-Propargylation of Ketones
作者:Igor D. Jurberg
DOI:10.1002/chem.201701433
日期:2017.7.21
A two‐step reaction sequence is described for the asymmetric formal α‐propargylation of ketones. This approach takes advantage of an aminocatalyzed conjugateaddition of ketones to alkylidene isoxazol‐5‐ones, followed by a controlled nitrosative degradation event. The target compounds can be accessed in broad scope, in moderate to good yields, perfect diastereocontrol and good to excellent enantioselectivity
Enhancing the Equilibrium of Dynamic Thia-Michael Reactions through Heterocyclic Design
作者:Alex E. Crolais、Neil D. Dolinski、Nicholas R. Boynton、Julia M. Radhakrishnan、Scott A. Snyder、Stuart J. Rowan
DOI:10.1021/jacs.3c03643
日期:2023.7.5
Although the catalyst-free dynamicthia-Michael (tM) reaction has been leveraged for a range of significant applications in materials science and pharmaceutical development, exploiting its full potential has been limited by relatively low equilibrium constants. To address this shortcoming, a new series of catalyst-free, room-temperature dynamicthia-Michael acceptors bearing an isoxazolone motif were
Action d'agents nucleophiles sur les 4-arylideneisoxazoline-5-ones, synthese et etude de la stereoisomerie de 4-cinnamylideneisoxazoline-5-ones.
作者:A. Maquestiau、Y. Van Haverbeke、R.N. Muller、G. Lo Vecchio、G. Grassi
DOI:10.1016/s0040-4039(01)87161-6
日期:1973.1
Cooperative Catalysis with Coupled Chiral Induction in 1,3-Dipolar Cycloadditions of Azomethine Ylides
作者:Alberto Cayuelas、Olatz Larrañaga、Verónica Selva、Carmen Nájera、Takahiko Akiyama、José M. Sansano、Abel de Cózar、José I. Miranda、Fernando P. Cossío
DOI:10.1002/chem.201801433
日期:2018.6.7
3‐Dipolar cycloadditions (1,3‐DC) between imino esters (as precursors of N‐metallated azomethine ylides) and π‐deficient alkenes are promoted by cooperative asymmetric Lewis acid/Brønsted base catalysis. The components of these catalytic pairs are silver saltsderivedfrom enantiopure commercially available BINOL‐based phosphoric acids and Cinchona alkaloids. Chiral phosphoric silver(I) salts promote
Gold-Catalyzed Cyclization and Subsequent Arylidene Group Transfer of <i>O</i>-Propioloyl Oximes
作者:Itaru Nakamura、Masashi Okamoto、Masahiro Terada
DOI:10.1021/ol100581m
日期:2010.6.4
Gold-catalyzed cyclizations of O-propioloyl oximes via C-N bond formation followed by arylidene group transfer were successfully carried out to afford the corresponding 4-arylideneisoxazol-5(4H)-ones in good to excellent yields. As an example, (E)-benzaldehyde O-3-phenylpropioloyl oxime (1a) was reacted in acetonitrile at 25 degrees C in the presence of Au(PPh(3))NTf(2) (5 mol %) to give 4-benzylidene-3-phenylisoxazol-5(4H)-one (2a) in 90% yield. On the basis of crossover experiments, the arylidene "migration" was shown to proceed in an intermolecular manner.