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Publication 101  


  1. P. Müller, N. Pautex, M.P. Doyle, V. Bagheri,
    “Rh(II)-Catalyzed Isomerizations of Cyclopropenes Evidence for Rh(II)-Complexed Vinylcarbene Intermediates”
    Helv. Chim. Acta 1990, 73, 1233-1241.

The thermocatalytic rearrangements of cyclopropenes 1-4 have been investigated in the presence of Rh(IT) perfiuorobutyrate. 1, 2, 3-Triphenylcyclopropene (1a) undergoes rearrangement lo diphenylindene 5a or, with alkoxycyclopropene derivatives, to α, β-unsaturated ketone 6. Furan formation occurs with 2, 3-diphenylcyclo-propenecarboxylate 2, but the diethyl counterpart 3 rearranges to dienoate 8. 2-Alkylcyclopropenecarboxylates 4 afforded (E)-methylidenecyclopentane derivatives 9 as the only isolable product in yields of ca. 35 %. A mechanism involving regio- and stereospecific cyclopropene ring opening to a Rh-complexed vinylcarbene and insertion of the latter into the C—H bond to give 9 is proposed. An analogous mechanism should account for the rearrangement products of 1 to 3.

DOI : 10.1002/hlca.19900730513 

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