Synthese von funktionalisierten Bi(cyclopropylidenen)
摘要:
In view of the synthesis of attractive triafulvalene precursors 9, a series of bi(cyclopropylidenes) 8 with vinyl-(8a), alkoxycarbonyl (8c -f), hydroxymethyl (8h), as well as protected hydroxymethyl groups (8g, 8i) have been prepared by simple one-pot reactions of the corresponding 1,2-dibromo-cyclopropanes 6 with BuLi/CuCl2 at -95 degrees. First experiments towards a direct low-temperature synthesis of bi(cyclopropylidenes) bearing good leaving groups 9k (X = AcO) and 91 (X = Br) are reported.
Thermodynamic Control of Diastereoselectivity in the Formal Nucleophilic Substitution of Bromocyclopropanes
作者:Joseph E. Banning、Anthony R. Prosser、Michael Rubin
DOI:10.1021/ol100187c
日期:2010.4.2
A new, general, and chemoselective protocol for the formal nucleophilic substitution of 2-bromocyclopropylcarboxamides Is described. A wide range of alcohols and phenols can be employed as pronucleophiles in this transformation, providing expeditious access to trans-cyclopropanol ethers. A new mode of the selectivity control through a thermodynamic equilibrium is realized, alternative to the previously described steric and directing modes.
Alnasleh, Bassam K.; Sherrill, William M.; Rubina, Marina, Journal of the American Chemical Society, 2009, vol. 131, p. 6906 - 6907
作者:Alnasleh, Bassam K.、Sherrill, William M.、Rubina, Marina、Banning, Joseph、Rubin, Michael