Ruthenium-catalyzed stereospecific decarboxylative allylation of non-stabilized ketone enolates

Abstract

The ruthenium-catalyzed stereospecific decarboxylative allylation of ketone enolates provides access to gamma,delta-unsaturated ketones with good yields and enantio-enrichments.

Transition metals in organic synthesis: Highlights for the year 2005

“…(71)) [618]. Ruthenium also catalyzed a stereospecific decarboxylative allylation of allyl ␤-keto esters [619].…”

Reactions of Ru(Cp∗) complexes with P(o-tolyl)3

“…[RuCp * (P(p-tol) 3 ) 2 CH 3 CN]PF 6 (6) and [RuCp * (g 6 -ptol)P(p-tol) 2 ]PF 6 (7). A solution of P(p-tol) 3 [PhACH@CHACH 2 -P(o-tol) 3 ]PF 6 (9) and [RuCp * g 6 -C 5 H 5 ACH@CHACH 2 P (o-tol) 3 ](PF 6 ) 2 (10). A solution of P(o-tol) 3 (34.9 mg, 0.115 mmol) in 1 mL acetone was added to a solution of [RuCp * (DMF) 2 (g 3 -phenylallyl)](PF 6 ) 2 (52.5 mg, 0.057 mmol) in 1 mL acetone.…”

“…A variety of complexes of ruthenium continue to attract interest both for their organometallic and catalytic chemistry [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The now readily available Ru(II) salts, [Ru(Cp or Cp * )(CH 3 CN) 3 ](PF 6 ) [4e], have been widely employed as starting materials in the synthesis, study and catalytic reactions of an increasing number of half sandwich complexes.…”

Pentamethylcyclopentadienyl–Ruthenium Catalysts for Regio‐ and Enantioselective Allylation of Nucleophiles

“…[12] Decarboxylative allylation of ketone enolates using the [{RuClA C H T U N G T R E N N U N G (Cp*)} 4 ]/bipyridine catalytic system proceeds also in a stereospecific manner (Scheme 9). [37] Here again, the p-s-p allyl interconversion is slow, and the rearrangement is highly stereospecific. The imperfect stereospecificity was attributed to a ruthenium-catalysed isomerisation of the starting material into the regioisomeric linear allyl b-ketoester, through reversible formation of h 3 -allyl-ruthenium intermediate.…”

“…[18] From the chirality point of view, stereospecific nucleophilic substitution starting from optically active substrates has been reported in the presence of 6 as catalyst. [12,37] However, it is very difficult to control the ste-A C H T U N G T R E N N U N G reochemistry of the ruthenium centre and enantioselective catalytic processes have been achieved only with catalysts bearing an optically pure ligand. Examples based on the uti- [22,24] and [23] in the presence of a chiral bis-oxazoline ligand will be presented.…”