Trifluoroacetyl-Activated Nitrogen−Nitrogen Bond Cleavage of Hydrazines by Samarium(II) Iodide
摘要:
Trifluoroacetyl derivatives of hydrazines undergo clean and efficient reductive cleavage of the N-N bond with SmI2 in the presence of MeOH. After N-trifluoroacetylation, acyl-, aryl-, and alkyl-substituted hydrazines are reductively cleaved by this method to afford trifluoroacetamides in yields ranging from 70 to 96%. These conditions accommodate alkene functionality, avoid racemization, and furnish chiral amines bearing a readily removable TFA protecting group.
Dual Activation in Asymmetric Allylsilane Addition to Chiral <i>N</i>-Acylhydrazones: Method Development, Mechanistic Studies, and Elaboration of Homoallylic Amine Adducts
作者:Gregory K. Friestad、Chandra Sekhar Korapala、Hui Ding
DOI:10.1021/jo052037d
日期:2006.1.1
CN bonds. In the presence of indium(III) trifluoromethanesulfonate [In(OTf)3], N-acylhydrazones undergo highly diastereoselective fluoride-initiated additions of allylsilanes (aza-Sakurai reaction). Mechanistic studies including control experiments and comparisons with allyltributylstannane, allylmagnesium bromide, and allylindium species implicate a dual activation mechanism involving addition of an
Trifluoroacetyl-Activated Nitrogen−Nitrogen Bond Cleavage of Hydrazines by Samarium(II) Iodide
作者:Hui Ding、Gregory K. Friestad
DOI:10.1021/ol036480r
日期:2004.2.1
Trifluoroacetyl derivatives of hydrazines undergo clean and efficient reductive cleavage of the N-N bond with SmI2 in the presence of MeOH. After N-trifluoroacetylation, acyl-, aryl-, and alkyl-substituted hydrazines are reductively cleaved by this method to afford trifluoroacetamides in yields ranging from 70 to 96%. These conditions accommodate alkene functionality, avoid racemization, and furnish chiral amines bearing a readily removable TFA protecting group.