Pd(II)-catalyzed cyclization of alkyne-tethered malononitriles nitrile insertion.

Herein, we have developed a Pd(II)-catalyzed cyclization of prochiral alkyne-tethered malononitriles to access five-membered carbocycles having a nitrile-containing all-carbon quaternary center. The reaction pathway involves a -acetoxypalladation, nitrile group insertions into the carbon-palladium bond and sequential deacetylation followed by -acetylation. Initial studies on asymmetric cyclization were also performed with chiral Pyox ligands.

Synthesis of α-Vinyltrialkoxysilanes via Nickel-Mediated Cross-Electrophile Coupling Reactions.

Vinyltrialkoxysilanes are indispensable for organic synthesis, particularly cross-coupling reactions. Hydrosilylation of alkynes inevitably yields α- and β-isomers of vinyltrialkoxysilanes even with complex ligands and catalysts, limiting its usage in organic synthesis. We report the synthesis of α-vinyltrialkoxysilanes via cross-electrophile C(sp)-C(sp) coupling of bromoalkenes.