An unexpected aminocyclopropane reductive rearrangement
摘要:
A reductive rearrangement of aminocyclopropanes is described for the synthesis of cis- or trans-fused bicyclic 1,2-diaminocyclobutanes. Ionization of a cyclic aminal using BF(3)center dot OEt(2) induces rearrangement to a cyclobutyl iminium ion, which is subsequently reduced by Et(3)SiH. Substitution with allyltrimethylsilane allows carbon incorporation, giving a quaternary center. Silyloxy-substituted cyclopropanes rearrange rapidly to cyclobutanones which react with NaBH(4) to provide 1,2-aminohydroxycyclobutanes. These aminals were generated by the reduction of a Boc-imide with DIBAL-H or LiBH(4). (C) 2007 Elsevier Ltd. All rights reserved.
An unexpected aminocyclopropane reductive rearrangement
摘要:
A reductive rearrangement of aminocyclopropanes is described for the synthesis of cis- or trans-fused bicyclic 1,2-diaminocyclobutanes. Ionization of a cyclic aminal using BF(3)center dot OEt(2) induces rearrangement to a cyclobutyl iminium ion, which is subsequently reduced by Et(3)SiH. Substitution with allyltrimethylsilane allows carbon incorporation, giving a quaternary center. Silyloxy-substituted cyclopropanes rearrange rapidly to cyclobutanones which react with NaBH(4) to provide 1,2-aminohydroxycyclobutanes. These aminals were generated by the reduction of a Boc-imide with DIBAL-H or LiBH(4). (C) 2007 Elsevier Ltd. All rights reserved.