Synthesis of 3,3-Disubstituted Heterocycles by Pd-Catalyzed Arylallylation of Unactivated Alkenes

Finding new methods of carbon-carbon bond formation is a key goal in expanding current methodology for heterocycle formation. Because of their inherently nonplanar shape, new methods of forming sp³-rich scaffolds are of particular importance. Although there are methods for combining heterocyclization and formation of new sp³-sp³ carbon-carbon bonds, these form the carbon-heteroatom bond rather than a carbon-carbon bond of the heterocycle. Here, we show a new alkene arylallylation reaction that generates a heterocycle with concomitant formation of two new carbon-carbon bonds. Furthermore, we demonstrate that this process occurs through an isohypsic (redox neutral) mechanism. Overall, this carboallylation reaction gives a new route to the synthesis of 3,3-disubstituted heterocycles.

Mechanistic investigations of a bifunctional squaramide organocatalyst in asymmetric Michael reaction and observation of stereoselective retro-Michael reaction

The mechanism of cinchona–squaramide organocatalytic Michael addition was studied usingin situIR and NMR experiments. As a result, not only kinetic parameters were determined but a stereoselective retro-Michael reaction was also observed.