77811-12-2Relevant academic research and scientific papers
Catalytic enantioselective allylation of dienals through the intermediacy of unsaturated π-allyl complexes
Zhang, Ping,Morken, James P.
supporting information; scheme or table, p. 12550 - 12551 (2010/01/30)
(Chemical Equation Presented) The nickel-catalyzed enantioselective addition of allylboronic acid pinacol ester [allylB(pin)] to >,β,γ,δ-unsaturated aldehydes is described. This reaction results in a remarkable inversion of substrate olefin geometry, providing the Z,E-configured reaction product in good enantioselectivity and olefin stereoselectivity. The reaction appears to proceed by conversion of the dienal to an unsaturated B-allyl complex followed by reductive elimination via transition state II. Enantioselectivities range from 73-94% ee for a range of δ-substituted dienals when chiral ligand L3 is employed.
A stereoselective palladium-mediated reductive coupling of electron-deficient terminal iodoalkenes
Batsanov, Andrei S.,Knowles, Jonathan P.,Samsam, Benedict,Whiting, Andrew
supporting information; experimental part, p. 227 - 233 (2009/04/11)
Iodoacrylate esters undergo palladium-catalysed reductive homocoupling to derive dienyl diester derivatives. This reductive coupling can be extended to ester-substituted terminal iododienes to derive tetraene diesters. In all cases, the reactions show relatively high levels of stereocontrol, which shows an inversion of stereochemistry about one iodoalkene unit. This process, and the suggestion that the reaction releases diiodine, is consistent with a syn-1,2-addition of an iodopalladium(II)-alkene species across another iodoalkene unit (carbometallation step), followed by reductive syn-elimination of iodopalladium iodide to derive palladium(II) iodide. It appears that under the reaction conditions employed, palladium(II) iodide may equilibrate to palladium(O) and diiodine, which can be observed or trapped out from the reaction mixture.
(ALLYLTHIO)ACETATE DIANION AS A MEW AND CONVENIENT REAGENT FOR THE STEREOSELECTIVE SYNTHESIS OF (2E,4E)DIENOATES FROM ALKYL HALIDES
Tanaka, Kazuhiko,Terauchi, Makoto,Kaji, Aritsune
, p. 315 - 318 (2007/10/02)
Treatment of (allylthio)acetate with lithium diisopropylamide followed by the addition of s-butyllithium produced a new dianion which could react with a variety of alkyl halides exclusively at the allylic position.The high regioselectivity of the allylic alkylation could be realized in the case of methyl (allylthio)acetate dianion.A convenient and general method for the stereoselective synthesis of (2E,4E)dienoates from alkyl halides has been developed.
