Iridium-catalyzed stereoselective [3+2] annulation of α-oxocarboxylic acids with 1,3-dienes
作者:Ryota Yabe、Yusuke Ebe、Takahiro Nishimura
DOI:10.1039/d1cc02003j
日期:——
The stereoselective annulation of α-oxocarboxylic acids with 1,3-dienes proceeded in the presence of a hydroxoiridiumcatalyst to give α-hydroxy-γ-lactones in good yields with high 3,5-trans relative stereochemistry. The use of a chiraldiene ligand for a cationic iridium complex enabled asymmetricannulation with high enantioselectivity.
feedstock isoprene with unactivated silanes has been developed using earth‐abundant iron catalysts. The manipulation of regioselectivity relies on fine modification of the coordination geometry of the iron center. While a bidentate pyridine imine ligand promoted the formation of allylic silanes through 4,1‐addition, selectivity for the 3,4‐adduct homoallylic silanes was observed with a tridentate nitrogen
multiple active sites. Herein, an orthogonalregulation of nucleophilic and electrophilicsites in the regiodivergent hydroamination of isoprene with indazoles is demonstrated. Under Pd‐hydride catalysis, the 1,2‐ or 4,3‐insertion pathway with respect to the electrophilicsites on isoprene could be controlled by the choice of ligands. In terms of the nucleophilicsites on indazoles, the reaction occurs
Ruthenium-Catalyzed Cross Metathesis of β-Myrcene and its Derivatives with Methyl Acrylate
作者:Arno Behr、Leif Johnen、Andreas Wintzer、Arzu Gümüş Çetin、Peter Neubert、Lutz Domke
DOI:10.1002/cctc.201500993
日期:2016.2
β‐myrcene with methylacrylate produces 3‐methylenecyclopent‐1‐ene in the presence of the Ru catalyst Neolyst M2 by ring‐closing metathesis in the first step. In the second step, the generated methylidene unit reacts with methylacrylate to give the corresponding unsaturated cyclic ester by crossmetathesis. Under the optimized reaction conditions (80 °C, Neolyst M2, 16 equivalents of methylacrylate), derivatives
Cyclic siloxanes that contain releasable active ingredients are described. The active ingredient can be an alcohol or enolizable carbonyl-containing compound such as a ketone, aldehyde, or ester. The product siloxanes are useful in a variety of personal and household care products where slow or controlled release of active ingredient is desired. A preferred embodiment utilizes substituents that when released as active ingredients are fragrant.