Deactivation of the Grubbs Carbene Complex [RuCl₂(CHPh)(PCy₃)₂] by Allylic Alcohols

Abstract

While the (hydroxymethyl)carbene complex [RuCl 2 ( CHCH 2 OH)(PCy 3 ) 2 ] ( 2 ), prepared by metathesis from [RuCl 2 ( CHPh)(PCy 3 ) 2 ] ( 1 ) and allyl alcohol, reacts in solution to give the carbonyl derivative [RuCl 2 (CO)(PCy 3 ) 2 ] ( 3 ), in the absence of solvent the methoxycarbene isomer [RuCl 2 ( CHOCH 3 )(PCy 3 ) 2 ] ( 4 ) is formed. The catalytic reaction of 1 with allyl alcohol affords, besides small amounts of ethene and acrolein, predominantly propionaldehyde; with 3-buten-2-ol and catalytic amounts of 1, 3-butanone is obtained exclusively.