6 used that a high yield of 2 was obtained and then only if the reaction was run at-78 “C and the phenyl isocyanide was added to 2 equiv of tert-butyllithium. Low yields resulted if both these requirements were not met. A reasonable explanation for the requirement of low temperature and the need for excess tert-butyllithium in solution is that the lithium aldimine 3 can further react with any excess phenyl isocyanide in solution to form a dimer* 4 which ...
