Polycyclic heteroaromatic ring construction driven by silver/cobalt co-catalyzed desulfonylative and defluorinative fragment-recombination of enol nonaflates with amidines
Hypervalent Iodine Chemistry: New Oxidation Reactions Using the Iodosylbenzene−Trimethylsilyl Azide Reagent Combination. Direct α- and β-Azido Functionalization of Triisopropylsilyl Enol Ethers
作者:Philip Magnus、Jérôme Lacour、P. Andrew Evans、Michael B. Roe、Christopher Hulme
DOI:10.1021/ja953906r
日期:1996.1.1
Treatment of triisopropylsilyl (TIPS) enolethers with PhIO/TMSN3/at −18 to −15 °C rapidly (5 min) gave β-azido TIPS enolethers in high yields, with only traces of the α-azido adduct. The reaction...
Catalytic [3+2] Annulation of Aminocyclopropanes for the Enantiospecific Synthesis of Cyclopentylamines
作者:Florian de Nanteuil、Jérôme Waser
DOI:10.1002/anie.201106255
日期:2011.12.9
With nitrogen too: The first catalytic [3+2] annulation of aminocyclopropanes with enol ethers is reported (see scheme; Phth=phthaloyl). The reaction worked with easily accessible phthalimidocyclopropanes using 5 mol % of SnCl4 in nearly quantitative yields. Polysubstituted cyclopentylamines, which are often present in bioactive compounds, were obtained with high diastereoselectivity and enantiospecificity
A metal-free, visible-light photoredox-catalyzed three-component [3 + 2 + 1] heteroannulation for accessing modular fluoroalkylated pyrimidines from readily available silyl enolether, amidine, and fluoroalkyl halide is developed. This protocol distinguishes itself by broad functional group tolerance in a regioselective manner, which provides a complement to the existing methods for the construction
Chemo‐ and Regioselective Ring Construction Driven by Visible‐Light Photoredox Catalysis: an Access to Fluoroalkylated Oxazolidines Featuring an All‐Substituted Carbon Stereocenter
ether, fluoroalkyl halide, and chiral amino alcohol in a single reaction vessel, which provides an efficient strategy for expanding the pool of pharmaceutically important heterocycles featuring an all‐substituted carbon stereocenter. This process proceeds efficiently in a chemo‐, regio‐, and stereoselective fashion under mild reaction conditions at room temperature and exhibits broad functional group
high reactivity of alkoxyl (RO·) radicals and their propensity to easily undergo β-scission or Hydrogen Atom Transfer (HAT) reactions, intermolecular alkoxylations involving RO· radicals are barely described. We report herein for the first time the efficient intermolecular trapping of alkoxyl radicals by silyl enol ethers. This photoredox-mediated protocol enables the introduction of both structurally