ja209679c_si_002.cif (43.44 kB)
Iridium-Catalyzed Addition of Aroyl Chlorides and Aliphatic Acid Chlorides to Terminal Alkynes
dataset
posted on 2012-01-18, 00:00 authored by Tomohiro Iwai, Tetsuaki Fujihara, Jun Terao, Yasushi TsujiIridium complexes show high catalytic activity in intermolecular
additions of acid chlorides to terminal alkynes to afford valuable
(Z)-β-chloro-α,β-unsaturated ketones.
Ligands in the catalytic system play a crucial role in this reaction.
An N-heterocyclic carbene (NHC) is an efficient ligand
for the addition of aroyl chlorides, while dicyclohexyl(2-methylphenyl)phosphine
(PCy2(o-Tol)) is indispensable for the
reaction of aliphatic acid chlorides. The addition reactions proceed
regio- and stereoselectively with suppression of decarbonylation and
β-hydrogen elimination, which have been two major intrinsic
problems in transition-metal-catalyzed reactions. Stoichiometric reactions
of active iridium catalysts with aroyl chlorides and aliphatic acid
chlorides are carried out to gain insights into the reaction mechanisms.