allylarenes with excess Grignard reagent. It occurs regiospecifically at the position of C(sp2)–H activation and represents a new method for the synthesis of 1,1-disubstituted olefins. The results of deuterium labeling experiments reveal an alkenyl/alkyl mechanism involving allylic internal C(sp2)–H activation and multiple intermolecular 1,2-, 1,3-, and 2,3-hydride shifts. These methods represent new
One-step method for the synthesis of aryl olefins from aryl aldehydes and aliphatic aldehydes
作者:Hanumant B. Borate、Supriya H. Gaikwad、Ananada S. Kudale、Subhash P. Chavan、Shrikant G. Pharande、Vitthal D. Wagh、Vikram S. Sawant
DOI:10.1016/j.tetlet.2013.01.008
日期:2013.3
A conceptually newone-step reaction affording unexpected aryl olefinic product from aromatic aldehyde, aliphatic aldehyde and malononitrile in the presence of acetic acid-ammonium acetate under mild reaction conditions without using any metal catalyst is reported. This novel reaction was used to prepare a number of substituted aryl olefins including new molecules.
Aryltriolborates as Air- and Water-Stable Bases for Wittig Olefination
作者:Wenhua Huang、Shuang-Hong Zhao、Ning Xu
DOI:10.1055/s-0034-1378919
日期:——
1-tris(hydroxymethyl)ethane, and aqueous tetrabutylammonium hydroxide. The aryltriolborates can be used as bases in Wittigreactions of aromatic aldehydes with all three types of phosphorus ylides: stabilized and semistabilized ylides can be generated at room temperature, and nonstabilizedylides at 120 °C (bath temperature). Tetrabutylammonium aryltriolborates have been synthesized in 37–66% yield by a one-pot
A facile and convenient sequential homobimetallic catalytic approach towards β-methylstyrenes. A one-pot Stille cross-coupling/isomerization strategy
作者:Sebastián O. Simonetti、Enrique L. Larghi、Teodoro S. Kaufman
DOI:10.1039/c4ob00604f
日期:——
A one-pot approach towards β-methylstyrenes is reported. The transformation involves a Stille cross-coupling reaction of aryl halides with allyltributylstannane, followed by an in situ Pd-catalyzed double bond conjugative migration.
Orthogonally Protected 1,2-Diols from Electron-Rich Alkenes Using Metal-Free Olefin <i>syn</i>-Dihydroxylation
作者:Ignacio Colomer、Rosimeire Coura Barcelos、Kirsten E. Christensen、Timothy J. Donohoe
DOI:10.1021/acs.orglett.6b02959
日期:2016.11.18
A new method for the stereoselective metal-free syn-dihydroxylation of electron-richolefins is reported, involving reaction with TEMPO/IBX in trifluoroethanol (TFE) or hexafluoroisopropanol (HFIP) and the addition of a suitable nucleophile. Orthogonally protected syn 1,2-diols were obtained with high levels of diastereocontrol, and these products were selectively deprotected and selectively functionalized