Pd‐catalyzed [3+2]‐dehydrogenative annulation reactions

Dynamic kinetic asymmetric [3 + 2] annulation reactions of aminocyclopropanes.

We report the first example of a dynamic kinetic asymmetric [3 + 2] annulation reaction of aminocyclopropanes with both enol ethers and aldehydes. Using a Cu catalyst and a commercially available bisoxazoline ligand, cyclopentyl- and tetrahydrofurylamines were obtained in 69-99% yield and up to a 98:2 enantiomeric ratio using the same reaction conditions. The method gives access to important en...

Cyclization and annulation reactions of nitrogen-substituted cyclopropanes and cyclobutanes.

Cyclization and annulation reactions initiated by ring-opening of small rings, especially cyclopropanes and cyclobutanes are now well-established in synthetic chemistry. Nevertheless, the potential of aminocyclopropanes and cyclobutanes, an important subclass for the synthesis of nitrogen-rich building blocks, has remained unexploited for a long time, despite important pioneering results. In th...

Annulation Reactions of ( Trialkylsilyl ) Ketenes : Synthesis of Substituted

Directed arene/alkyne annulation reactions via aerobic copper catalysis.

We describe a straightforward protocol for a smooth dehydrogenative annulation reaction between various arenes and terminal alkynes using a catalytic amount of CuBr2 and molecular oxygen. 3-Methyleneisoindoline derivatives are prepared in high yields.

Understanding the cooperative NHC/LA catalysis for stereoselective annulation reactions with homoenolates. A DFT study.

The role of Ti(Oi-Pr)(4) Lewis acid (LA) in the cooperative N-heterocyclic carbene (NHC)/LA catalyzed addition of enals to enones to yield cis-cyclopentenes has been investigated using DFT methods at the B3LYP/6-31G** computational level. Ti(IV) effectively catalyzes the reaction by formation of a complex with cinnamaldehyde 1, which favors the nucleophilic attack of NHC 5 on 1, and the subsequ...