Cobalt-catalyzed alkyne cyclotrimerization and crossed [2 + 2 + 2] cycloadditions are developed in a plug flow reactor. The protocol generally uses 5 mol % of Co2(CO)8 and is scalable at least at multigram scale. Efficient and scalable use of Co2(CO)8 for crossed reactions of diynes and alkynes has hardly any precedent.
combination of cationic rhodium(I) complexes with N-phosphino tert-butylsulfinamides (PNSO) ligands is efficient for catalytic intra- and intermolecular [2+2+2] cycloaddition reactions. PNSO ligands are a new class of chiral bidentate ligands, which have the characteristic of combining the easily accessible sulfur chirality with the coordinating capacity of phosphorous. Cycloaddition of open-chained and