Non-stabilized diazoalkane synthesis <i>via</i> the oxidation of free hydrazones by iodosylbenzene and application in <i>in situ</i> MIRC cyclopropanation
作者:Emmanuelle M. D. Allouche、André B. Charette
DOI:10.1039/c8sc05558k
日期:——
powerful reagents in organic synthesis, but the risks associated with their toxicity and instability often limit their uses. Herein we describe an efficient, easy-to-handle and safe batch protocol for the in situ generation and cyclopropanation of these highly reactive non-stabilized diazoalkanes through the oxidation of free hydrazones using iodosylbenzene. Numerous substituted cyclopropanes have been
Cyclopropane formation by electroreductive coupling of activated olefins and gem-polyhalo compounds
作者:Eric Léonel、Jean Paul Paugam、Sylvie Condon-Gueugnot、Jean-Yves Nédélec
DOI:10.1016/s0040-4020(98)00059-3
日期:1998.3
be involved to lead to the products. The radical anion of the olefin can react with the halo compound by electron-tranfer followed by radical coupling, or be reduced into the dianion which reacts by nucleophilicdisplacement.
Cyclopropane formation by nickel-catalysed electroreductive coupling of activated olefins and unactivated gem-dibromo compounds
作者:Stéphane Sengmany、Eric Léonel、Jean Paul Paugam、Jean-Yves Nédélec
DOI:10.1016/s0040-4020(01)01133-4
日期:2002.1
Cyclopropylderivatives have been prepared with good yields by transition-metal catalysed electroreductive coupling of activatedolefins and unactivated gem-dibromo compounds. This electrolysis is characterized by the use of a Fe/Ni catalyst system, acetonitrile as the solvent and a catalytic amount of triphenylphosphine as ligand. This procedure is a good alternative to the classical preparations