Stereo- and Enantioselective Reactions of Thioaldehydes, Thioketones, Thioketenes, and Thionolactones Mediated by Ruthenium Complexes

The Lactone Concept: An Efficient Pathway to Axially Chiral Natural Products and Useful Reagents

“…The chiral ruthenium complex thus recovered can be converted back into the original complex in one step, without loss of stereochemical purity. 39,86,87 This ring cleavage with cheap, achiral reductants, combined with the possibility of recycling the chiral ruthenium reagent, constitutes an interesting novel alternative to the use of chiral hydride transfer reagents.…”

Convenient Synthesis of [(η5-C5Me5)Ru(NCMe)3]PF6 and the Phosphine Derivatives [(η5-C5Me5)Ru(PR3)2(NCMe)]PF6

“…Half-sandwich ruthenium complexes of the type [CpRu(L)(L‘)(L‘ ‘)] (Cp = η 5 -C 5 H 5 , η 5 -C 5 Me 5 ) have a quite prominent role in the chemistry of the late transition metals. , The ruthenium−L bonds are kinetically stable, and the high π-donor capacity of the [CpRu(L) 2 ] complex fragment may in turn be exploited to “tame” unstable π-acceptor ligands such as carbenes, vinylidenes, silylenes, silenes, thioaldehydes, sulfenes, sulfur monoxide, or sulfur trioxide, to name a few. In this regard, the pentamethylcyclopentadienyl complexes are even superior to their C 5 H 5 congeners due to improved electron donation as well as increased steric shielding.Their synthesis usually starts out from the Ru(III) complex [(η 5 -C 5 Me 5 )RuCl 2 ] n ( 1 ), which is readily obtained from RuCl 3 ·3H 2 O and HC 5 Me 5 .…”