- Tandem C(sp3)?H Arylation/Oxidation and Arylation/Allylic Substitution of Isoindolinones
-
Isoindolinones comprise an important class of medicinally active compounds. Herein we report a straightforward functionalization of isoindolinones with aryl bromides (22 examples) using a palladium(II) acetate/NIXANTPHOS-based catalyst system. Additionally 3-aryl-3-hydroxyisoindolinone derivatives, which exhibit anti-tumor activity, can be accessed via a tandem reaction. Thus, when the arylation product is exposed to air under basic conditions, in situ oxidation takes place to install the 3-hydroxy group. Furthermore, a tandem arylation/allylic substitution reaction is advanced in which both the arylation and allylic substitution are catalyzed by the same palladium catalyst. Finally, a tandem arylation/alkylation procedure is presented. These tandem reactions enable the synthesis of a variety of structurally diverse isoindolinone derivatives from common starting materials. (Figure presented.).
- Jiménez, Jacqueline,Kim, Byeong-Seon,Walsh, Patrick J.
-
supporting information
p. 2829 - 2837
(2016/09/13)
-
- Electrogenerated Superoxide-Activated Carbon Dioxide. A New Mild and Safe Approach to Organic Carbamates
-
The electrochemical reduction of O2 (E = -1.0 V vs SCE) in dipolar aprotic solvents in the presence of CO2 gave a carboxylating reagent (O2·-/CO2) able to convert amines and different types of their derivatives into carbamates. Primary and secondary aliphatic and aromatic amines were converted into the corresponding ethyl carbamates by the addition of EtI to the carbamate anions generated in the first step of the reactions. The yields were dependent on the nucleophilicity of the nitrogen atom ω-Bromoethyl- and propylamine gave 2-oxazolidinone and tetrahydro-l,3-oxazm-2-one in moderate yields. N-Acyl or N-(alkoxycarbonyl)alkylamines bearing a leaving group at the β position of the alkyl substituent were converted into 3-substituted-2-oxazolidinones in high yields. By using chiral substrates, enantiopure 3-alkoxycarbonyl(or acyl)-4-substituted oxazolidin-2-ones (70-85% isolated yields) were obtained. This represents a new mild and safe route to these important auxiliaries for asymmetric synthesis. Some limitations of the process are also evidenced and accounted for.
- Casadei, Maria Antonietta,Moracci, Franco Micheletti,Zappia, Giovanni,Inesi, Achille,Rossi, Leucio
-
p. 6754 - 6759
(2007/10/03)
-