The fragrance compound indomuscone is used here as a
scaffold to
prepare two different sterically hindered phosphines, one aromatic
and another alkylic, in good yields, after four synthetic steps. The
new phosphines show enhanced electronic and steric properties when
compared to benchmark commercial phosphine ligands, which is reflected
in the catalytic results obtained for representative palladium-catalyzed
reactions such as the telomerization reaction, the Buchwald–Hartwig
and Suzuki cross-coupling reactions of chloroaromatic rings, and the
semi-hydrogenation reaction of an alkyne. In particular, the indomuscone-based
aromatic phosphine ligand leads to the highest selectivity for the
tail-to-head telomerization product between isoprene and methanol,
while the indomuscone-based alkylic phosphine ligand shows extraordinary
similarities with the Buchwald-type SPhos phosphine ligand.