Barriers to inversion at nitrogen in bicyclic amines and hydrazines

✍ Scribed by John W. Davies; John R. Malpass; Richard E. Moss

• Book ID: 104222219
• Publisher: Elsevier Science
• Year: 1985
• Tongue: French
• Weight: 244 KB
• Volume: 26
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)88951-0

✦ Synopsis

Nitrogen inversion barriers have been measured for 7-chloro-1,7-diazabicyclo-t2.2.11 heptane and 12.2.21octane; the unusual nature of the bridging nitrogen in bicycle [2.2.1) systems is discussed.

The effects of ring strain and heteroatom substitution in raising the barrier to inversion are well known.

1 We have been interested in the inversion process at nitrogen in strained asabicycles2 and, in particular, in derivatives of the 7-azabicyclo[2.2.1]heptane skeleton. In this latter system, the conformational stability at nitrogen has been sufficient to allow study of the stereochemical implications of reactions at nitrogen.

3

We have also studied the diaza- bicycles (1) in order to assess the combined influence of the so-called 'bicyclic effect" and the presence of an additional adjacent nitrogen on both the stereochemical integrity at nitrogen and on the chemistry of (1). The homologue (2) was included for comparison purposes.