RESUMO
We report herein a facile synthetic method for converting unactivated (hetero)aryl electrophiles into ß-fluoroethylated (hetero)arenes via nickel-catalyzed reductive cross-couplings. This coupling reaction features the involvement of FCH2 CH2 radical intermediate rather than ß-fluoroethyl manganese species which provides effective solutions to the problematic ß-fluoride side eliminations. The practical value of this protocol is further demonstrated by the late-stage modification of several complex ArCl or ArOH-derived bioactive molecules.
RESUMO
A novel palladium-catalyzed C-H double carbonylation introduces two adjacent carbonyl groups for the synthesis of isatins from readily available anilines. The reaction proceeds under atmospheric pressure of CO with high regioselectivity and without any additives. Density functional theory investigations indicate that the palladium-catalyzed double carbonylation catalytic cycle is plausible.
RESUMO
Sulfamic acid (NH(2)SO(3)H, SA) was used as an efficient, inexpensive, non-toxic and recyclable green catalyst for the ultrasound-assisted one-pot Mannich reaction of aldehydes with ketones and amines. This ultrasound protocol has advantages of high yield, mild condition, no environmental pollution, and simple work-up procedures. Most importantly, beta-aminocarbonyl compounds with ortho-substituted aromatic amines are obtained in acceptable to good yields by this methodology for the first time.