Hydration of terminal alkynes to aldehydes in aqueous micellar solutions by ruthenium(II) catalysis; first anti-Markovnikov addition of water to propargylic alcohols

The hydration of terminal alkynes and of propargylic alcohols to the corres ponding aldehyde derivatives is conveniently carried out at 60 degreesC in an aqueous micellar environment, in the presence of 5 mol% of the indenyl r uthenium(II) complex [Ru(eta (5)-C9H7)Cl(PPh3)(2)]. Higher yields and impro ved regioselectivity of aldehyde versus ketone as well as reaction conditio ns, in particular temperature and catalyst load, are found with respect to a solvent mixture 2-propanol-water, due to the aggregating conditions of th e micellar solution. The reactions of the propargylic alcohols indicate the tolerance of the hydroxy functionality by the ruthenium complex. (C) 2001 Elsevier Science Ltd. All rights reserved.