Trifluoroacetyl-activated nitrogen-nitrogen bond cleavage of hydrazines by samarium(II) iodide

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.