Unsymmetrical tin(II) amides can be generated, in situ, by adding one
equivalent of an amine to bis(bistrimethylsilylamino) tin, Sn[N(TMS)2]
2. Treatment of carboxylic acids with these tin(II) reagents derived f
rom alkyl or aryl amines results in smooth conversion to the correspon
ding N-alkyl or N-aryl amides.