An atom-economic and selective ruthenium-catalyzed redox isomerization of propargylic alcohols. An efficient strategy for the synthesis of leukotrienes.
Catalytic ruthenium complexes in conjunction with an indium cocatalyst and Bronsted acid isomerize primary and secondary propargylic alcohols in good yields to provide trans enals and enones exclusively. Readily available indenylbis(triphenylphosphine)ruthenium chloride, in the presence of indium triflate and camphorsulfonic acid, gives the best turnover numbers and reactivity with the broadest range of substrates. Deuterium labeling experiments suggest that the process occurs through propargylic hydride migration followed by protic cleavage of the resultant vinylruthenium intermediate. Application of this method to the synthesis of leukotriene B4 demonstrates its utility and extraordinary selectivity.
Trost
Barry M
BM
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA. bmtrost@stanford.edu
Livingston
Robert C
RC
D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D007536:Isomerism; D007975:Leukotriene B4 / Q000138:chemical synthesis*; D009942:Organometallic Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D020005:Propanols / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
D000480:Alkynes; D009942:Organometallic Compounds; D020005:Propanols; D007975:Leukotriene B4; D012428:Ruthenium; C028255:propargyl alcohol