Michael Additions versus Cycloaddition Condensations with Ethyl Nitroacetate and Electron-Deficient Olefins
作者:Elena Trogu、Francesco De Sarlo、Fabrizio Machetti
DOI:10.1002/chem.200802652
日期:2009.8.10
nitroacetate (1) reacts with electron‐poor olefins in the presence of a base to give either the Michael adducts 3 or the isoxazoline cycloadducts 4, resulting from water elimination. The proportions of the two products depend on the reaction conditions and change in the course of the process. Kinetic profiles for the two reactions show that the cycloaddition‐condensations require long induction times that dramatically
E-factor minimized protocols for the polystyryl-BEMP catalyzed conjugate additions of various nucleophiles to α,β-unsaturated carbonyl compounds
作者:Simona Bonollo、Daniela Lanari、Julie M. Longo、Luigi Vaccaro
DOI:10.1039/c1gc16088e
日期:——
Efficient protocols for the addition of carbon-, sulphur- and nitrogen-nucleophiles to α,β-unsaturated carbonylcompounds catalyzed by PS-BEMP have been reported. The adoption of solvent-free conditions (SolFC) was crucial for improving the efficiency of all the processes, while by using an organic reaction medium poor results were obtained. Addition reactions were performed by using equimolar amounts
Reactivity of [60]Fullerene with Primary Nitro Compounds: Addition or Catalysed Condensation to Isoxazolo[60]fullerenes
作者:Giacomo Biagiotti、Stefano Cicchi、Francesco De Sarlo、Fabrizio Machetti
DOI:10.1002/ejoc.201402990
日期:2014.12
addition products, depending on the nitrocompound and catalyst. The former product was favoured by the use of CuII in the catalytic system. Conversely, [60]fullerene underwent catalytic condensation, even in the absence of copper(II) salts, only with activatednitrocompounds and addition only with nitroalkanes in excess base. Note, the formal conjugated fullerene addition product was obtained in
Conjugate Addition versus Cycloaddition/Condensation of Nitro Compounds in Water: Selectivity, Acid-Base Catalysis, and Induction Period
作者:Luca Guideri、Francesco De Sarlo、Fabrizio Machetti
DOI:10.1002/chem.201202698
日期:2013.1.7
react in water as in chloroform with electron‐deficient dipolarophiles to give condensation or conjugate addition products under basecatalysis. In general, high selectivity towards condensation is observed in water, with shorter induction periods than in chloroform. In water, condensations slowly occur even without base; kinetic profiles evidence the catalytic effect of the base, which should be related