Search

The microwave-assisted intramolecular [3 + 2] cycloaddition reaction of azomethine ylides to activated and nonactivated alkenes and alkynes is described. The procedure allows the synthesis of pyrrolidines and pyrrole products in good to excellent overall yields in short reaction times. It appears from parallel comparative studies that the microwave procedure favors the reaction times and overall purity of the crude reaction mixture. The reactions can also be performed in the absence of solvent. [reaction: see text]

Reaction of N-unsubstituted ketimines with organoaluminum reagents prepared from allylic and propargylic halides, allows to prepare, in good yields, tertiary carbinamines with three different groups (phenyl, alkyl and α-unsaturated group) on the tertiary carbon center.

The reaction between Grignard reagents prepared from allylic or propargylic halides and the N-phenylsulfenimine derived from the heptane-2,6-dione affords primary 1-alkenyl (or alkynyl)-3-methylcyclohex-2-enamines in good yields.

The synthesis of azobenzene derivatives and of azo-linked carbohydrate moieties is reviewed. The report contains 119 references. Figure options Download full-size image Download as PowerPoint slide

The straightforward synthesis of families of novel tri-cyclic and tetracyclic pyrrolino and indolino heterocycles in a one-pot [3+2]-cycloaddition reaction is described. The process enables the synthesis of diversified pyrroles or pyrrolines in high yields in a single step. Microwave and conventional thermal conditions were explored, with remarkable acceleration observed under the microwave conditions.