The unexpected formation of N-benzylated tertiary amines from their corresponding CBZ-protected precursors

The unexpected formation of N-benzyl tertiary amines was observed during th e hydrogenolysis of their corresponding CBZ-protected secondary amines, ind icating a potential problem for the industrial application of a process oth erwise thought to be robust. The reaction is favoured by low hydrogen avail ability, and under such conditions competitive formation of N-benzyl analog ues occurs rather than affording exclusively the expected free amine. (C) 2 000 Elsevier Science B.V. All rights reserved.