ol048351w_si_001.pdf (3.31 MB)
Regioselectivity Control in a Ruthenium-Catalyzed Cycloisomerization of Diyne-ols
journal contribution
posted on 2004-11-11, 00:00 authored by Barry M. Trost, Michael T. Rudd, Moisés Gulías Costa, Philip I. Lee, Andrew E. PomerantzThe ruthenium-catalyzed cycloisomerization of diynes containing one silyl alkyne and one propargyl alcohol yields 2-silyl-[6H]-pyrans instead
of the expected unsaturated acylsilanes except when additional conjugation of a aromatic ring is present at the δ-position. Under certain
conditions, a facile ruthenium-catalyzed isomerization of the product takes place as well. This regioselectivity of the cyclization can be controlled
by the choice of solvent system. DFT calculations confirm the expected greater stability of the silyl-pyrans relative to the acylsilanes.