107644-69-9Relevant academic research and scientific papers
On the Regioselectivity and Stereoselectivity of the Carbene Transfer from Fischer Carbene Complexes to Trisubstituted Electron-Deficient 1,3-Dienes
Buchert, Matthias,Hoffmann, Matthias,Reissig, Hans-Ulrich
, p. 605 - 614 (2007/10/02)
Thermal reactions of Fischer carbene complex 1 with trisubstituted electron-deficient 1,3-dienes 7, 8, 23, 25, 32, and 35 provided highly substituted vinylcyclopropanes in good yields.The carbene transfer proceeds highly regioselectively favouring cyclopropanation of the double bond not bearing the ester function.In addition, the diastereoselectivity is generally fairly high in preference of cyclopropanes with the methoxy group cis-positioned with respect to the olefin moiety.The reaction of methylcarbene complex 2 with diene ester 8 displays inversed regioselectivity.These ovservations are discussed together with solvent effects, and a mechanistic rationale is presented. - Key Words: Chromium complexes/ Carbene complexes/ 1,3-Dienes, electron-deficient/ Cycloadditions/ Vinylcyclopropanes, donor-acceptor-substituted/ Diastereoselectivity/ Regioselectivity
A FACILE, STEREOSELECTIVE PREPARATION OF (Z)-2,4-PENTADIENOATES BY FAVORSKII REARRANGEMENT
Engler, Thomas A.,Falter, Wolfgang
, p. 4115 - 4118 (2007/10/02)
Reaction of 1,3,4-tribromo-2-alkanones, efficiently prepared by direct bromination of the parent enone, with methanolic sodium methoxide gives methyl (Z)-2,4-pentadienoates with high (Z) selectivity about the α,β-double bond.
