A Simple Procedure for the Synthesis of β-Hydroxyallenamides via Homoallenylation of Aldehydes

Synergistic Pd/Cu-catalysed regio- and stereoselective borylation of allenylic carbonates

A simple Pd/Cu-catalyzed borylation of allenylic carbonates with B₂Pin₂ was developed using a cheap P(OEt)₃ ligand. Under mild neutral conditions, 2-boryl 1,3-butadienes were obtained selectively in moderate to high yields. Furthermore, the use of different diboron reagents was also feasible in the reaction.

Addition of Chloroprene Grignards to Aromatic Aldehydes: Synthesis of Homoallenyl Alcohols

A general procedure for the one-pot synthesis of racemic homoallenyl alcohols from the corresponding aldehyde and chloroprene-derived Grignards is described. Employing bis[2-dimethylaminoethyl]ether (BDMAEE) as an additive at low temperatures shifts the selectivity of the chloroprene Grignard addition to aldehydes such that it is almost exclusive toward allene formation. In a set of follow-up experiments, simple and more elaborate methods for further derivatization have been demonstrated, allowing quick access to more complex structures.

Ligand-free, catalytic and regioselective hydroboration of selenoalkynes

The copper-catalyzed hydroboration of selenoalkynes in a regio- and stereoselective fashion is reported, delivering selenium-containing vinylboronate products in good yields.