One-pot sequential four-component coupling via Cp*RuCl-catalyzed cyclotrimerization and Suzuki–Miyaura coupling

The catalytic intermolecular cyclotrimerization of alkynylboronates, propargyl alcohols, and terminal alkynes was accomplished by means of the ruthenium catalysis and the temporary tethering approach with the C–B–O linkage to give rise to highly substituted arylboronates with excellent selectivity. The resultant arylboronates were further converted to highly substituted biaryls via the Suzuki–Miyaura coupling with various aryl iodides using Pd2(dba)3/PCy3 as a catalyst precursor in aqueous toluene. As a consequence, the four-component coupling approach to highly substituted biaryls was successfully established by combining these two operations into a sequential one-pot process.