text:  <unk> of nucleophiles with N @-@ unsubstituted <unk> is quite versatile in the breadth of possible nucleophiles and corresponding products . <unk> may be derived from the amination of secondary or tertiary amines , <unk> and <unk> may be formed from their corresponding alcohols and thiols , <unk> may be formed from thioethers and α @-@ <unk> may be formed by attack of corresponding <unk> . 
  