Transmetallation with palladium(II) of an organomercurial arising from mercury(II)-mediated cyclopropane cleavage. Tuning of the palladium reactivity and a novel, intramolecular redox reaction
An Approach toward the Triquinane-Type Skeleton via Reagent-Controlled Skeletal Rearrangements. A Facile Method for Protection−Deprotection of Organomercurials, Tuning the Selectivity of Wagner−Meerwein Migrations, and a New Route to Annulated Lactones
rearrangement (3 --> 8), (2) an intramolecularorganometallicaddition across a C=O bond triggered by activation of the C-HgX group by means of Me(3)CuLi(2) (14 --> 26), and (3) selective, reagent-controlled skeletal rearrangements (43 --> 47 with Tl(3+) or Hg(2+); 43 --> 51 + 52 with Pd(2+); 44 --> 47 with Pd(2+)). A new method for protection/deprotection of organomercurials has been developed, which allows
Regioselective opening of a cyclopropane ring by mercury(II) and transmetalation of the product with molybdenum. A novel, stereoelectronically controlled, skeletal rearrangement ans Grob-type fragmentation of organomolybdenum intermediates
作者:Jirˇí Sˇrogl、Pavel Kocˇovský
DOI:10.1016/s0040-4039(00)61108-5
日期:1992.9
Organomercurial 2, arising by a regioselective ring-opening of cyclopropane derivative 1, can be transmetalated with Mo-reagents to initially generate complexes 3 and 7. while 3 reacts further via a stereoelectronically controlled cascade rearrangement to afford 6, complex 7 favors a Grob-type fragmentation leading to 9.
Transmetallation with palladium(<scp>II</scp>) of an organomercurial arising from mercury(<scp>II</scp>)-mediated cyclopropane cleavage. Tuning of the palladium reactivity and a novel, intramolecular redox reaction
The cleavage of the fused-ring cyclopropane hydroxy derivative 1 by means of HgII is highly stereoselective and gives a rearranged organomercurial 3, transmetallation of which with PdII can be controlled by ligands to afford either lactol 4 or acid 8; the latter compound is formed via an intramolecular insertion of Pd into the C–H bond (6→7), as evidenced by isotopic labelling.
Corner opening of cyclopropanes by mercury(II) and thallium(III) and transmetalation of the intermediate organomercurials. A novel, stereoselective approach to cyclobutanes and cyclopropanes
compared, and further evidence for the exclusive corner selectivity for Hg2+ is provided by isotope labeling. Cleavage of cyclopropyl derivative 1 with Hg(NO3)2, followed by KBr quenching, afforded the stable, rearranged organomercurial 3, whose transmetalation has been studied. Whereas reaction of 3 with Pd(I1) afforded lactol 4, treatment with MezCuLi resulted in the formation of cyclobutanol derivative